Designing the RiverCare knowledge base and web-collaborative platform to exchange knowledge in river management

NASA Astrophysics Data System (ADS)

Cortes Arevalo, Juliette; den Haan, Robert-Jan; van der Voort, Mascha; Hulscher, Suzanne

2016-04-01

Effective communication strategies are necessary between different scientific disciplines, practitioners and non-experts for a shared understanding and better implementation of river management measures. In that context, the RiverCare program aims to get a better understanding of riverine measures that are being implemented towards self-sustaining multifunctional rivers in the Netherlands. During the RiverCare program, user committees are organized between the researchers and practitioners to discuss the aim and value of RiverCare outputs, related assumptions and uncertainties behind scientific results. Beyond the RiverCare program end, knowledge about river interventions, integrated effects, management and self-sustaining applications will be available to experts and non-experts by means of River Care communication tools: A web-collaborative platform and a serious gaming environment. As part of the communication project of RiverCare, we are designing the RiverCare web-collaborative platform and the knowledge-base behind that platform. We aim at promoting collaborative efforts and knowledge exchange in river management. However, knowledge exchange does not magically happen. Consultation and discussion of RiverCare outputs as well as elicitation of perspectives and preferences from different actors about the effects of riverine measures has to be facilitated. During the RiverCare research activities, the platform will support the user committees or collaborative sessions that are regularly held with the organizations directly benefiting from our research, at project level or in study areas. The design process of the collaborative platform follows an user centred approach to identify user requirements, co-create a conceptual design and iterative develop and evaluate prototypes of the platform. The envisioned web-collaborative platform opens with an explanation and visualisation of the RiverCare outputs that are available in the knowledge base. Collaborative sessions are initiated by one facilitator that invites other users to contribute by agreeing on an objective for the session and ways and period of collaboration. Upon login, users can join the different sessions that they are invited or will be willing to participate. Within these sessions, users collaboratively engage on the topic at hand, acquiring knowledge about the ongoing results of RiverCare, sharing knowledge between actors and co-constructing new knowledge in the process as input for RiverCare research activities. An overview of each session will be presented to registered and non-registered users to document collaboration efforts and promote interaction with actors outside RiverCare. At the user requirements analysis stage of the collaborative platform, a questionnaire and workshop session was launched to uncover the end user's preferences and expectations about the tool to be designed. Results comprised insights about design criteria of the collaborative platform. The user requirements will be followed by interview sessions with RiverCare researchers and user committee members to identify considerations for data management, objectives of collaboration, expected outputs and indicators to evaluate the collaborative platform. On one side, considerations of intended users are important for co-designing tools that effectively communicate and promote a shared understanding of scientific outputs. On the other one, active involvement of end-users is important for the establishment of measurable indicators to evaluate the tool and the collaborative process.

Multi-octave spectral beam combiner on ultra-broadband photonic integrated circuit platform.

PubMed

Stanton, Eric J; Heck, Martijn J R; Bovington, Jock; Spott, Alexander; Bowers, John E

2015-05-04

We present the design of a novel platform that is able to combine optical frequency bands spanning 4.2 octaves from ultraviolet to mid-wave infrared into a single, low M2 output waveguide. We present the design and realization of a key component in this platform that combines the wavelength bands of 350 nm - 1500 nm and 1500 nm - 6500 nm with demonstrated efficiency greater than 90% in near-infrared and mid-wave infrared. The multi-octave spectral beam combiner concept is realized using an integrated platform with silicon nitride waveguides and silicon waveguides. Simulated bandwidth is shown to be over four octaves, and measured bandwidth is shown over two octaves, limited by the availability of sources.

High Power Broadband Multispectral Source on a Hybrid Silicon Chip

DTIC Science & Technology

2017-03-14

insulator (SONOI) waveguide platform are demonstrated and emit over 200 mW pulsed output power at room temperature. Improvements are made to the 1.5-µm...silicon-on-nitride-on- insulator (SONOI) waveguide platform are demonstrated and emit over 200 mW pulsed output power at room temperature. Improvements are...optical bandwidth of the erbium-doped-fiber-amplifier with densely-spaced frequency channels. To extend the spectral capacity of the Si-on- insulator

Hypercalcemia in a bodybuilder with cosmetic silicone injections.

PubMed

Hamadeh, Majdi; Fares, Jawad; Maatouk, Khalil; Darwish, Mohamad

2018-04-13

Granulomatous hypercalcemia due to silicone injections is a rare disease with scarce literature. We present a case of a 35-year-old Caucasian male bodybuilder with multiple silicone injections in his upper extremities who developed hypercalcemia and urinary symptoms. He necessitated two sessions of dialysis. A biopsy of the upper arm showed granulomatous tissue. Corticosteroids were administered to relieve symptoms and reverse laboratory abnormalities. Silicone-induced hypercalcemia should be on high alert because of the increasing trend of body contour enhancements with injections, implants and fillers.

Telecom-Wavelength Bottom-up Nanobeam Lasers on Silicon-on-Insulator.

PubMed

Kim, Hyunseok; Lee, Wook-Jae; Farrell, Alan C; Balgarkashi, Akshay; Huffaker, Diana L

2017-09-13

Semiconductor nanowire lasers are considered promising ultracompact and energy-efficient light sources in the field of nanophotonics. Although the integration of nanowire lasers onto silicon photonic platforms is an innovative path toward chip-scale optical communications and photonic integrated circuits, operating nanowire lasers at telecom-wavelengths remains challenging. Here, we report on InGaAs nanowire array lasers on a silicon-on-insulator platform operating up to 1440 nm at room temperature. Bottom-up photonic crystal nanobeam cavities are formed by growing nanowires as ordered arrays using selective-area epitaxy, and single-mode lasing by optical pumping is demonstrated. We also show that arrays of nanobeam lasers with individually tunable wavelengths can be integrated on a single chip by the simple adjustment of the lithographically defined growth pattern. These results exemplify a practical approach toward nanowire lasers for silicon photonics.

Luneburg lens in silicon photonics.

PubMed

Di Falco, Andrea; Kehr, Susanne C; Leonhardt, Ulf

2011-03-14

The Luneburg lens is an aberration-free lens that focuses light from all directions equally well. We fabricated and tested a Luneburg lens in silicon photonics. Such fully-integrated lenses may become the building blocks of compact Fourier optics on chips. Furthermore, our fabrication technique is sufficiently versatile for making perfect imaging devices on silicon platforms.

Launching of multi-project wafer runs in ePIXfab with micron-scale silicon rib waveguide technology

NASA Astrophysics Data System (ADS)

Aalto, Timo; Cherchi, Matteo; Harjanne, Mikko; Ylinen, Sami; Kapulainen, Markku; Vehmas, Tapani

2014-03-01

Silicon photonics is a rapidly growing R&D field where universities, institutes and companies are all involved and the business expectations for the next few years are high. One of the key enabling elements that led to the present success of silicon photonics is ePIXfab. It is a consortium of institutes that has together offered multi-project wafer (MPW) runs, packaging services, training, and feasibility studies. These services have significantly lowered the barrier of various research groups and companies to start developing silicon photonics. Until now the MPW services have been offered by the ePIXfab partners IMEC, CEA-Leti and IHP, which all use CMOS-type silicon photonics technology with a typical silicon-on-insulator (SOI) waveguide thickness of 220 nm. In November 2013 this MPW offering was expanded by the ePIXfab partner VTT that opened the access to its 3 μm SOI waveguide platform via ePIXfab MPW runs. This technology platform is complementary to the mainstream silicon photonics technology (220 nm) and it offers such benefits as very low losses, small polarization dependency, ultrabroadband operation and low starting costs

A collaborative platform for consensus sessions in pathology over Internet.

PubMed

Zapletal, Eric; Le Bozec, Christel; Degoulet, Patrice; Jaulent, Marie-Christine

2003-01-01

The design of valid databases in pathology faces the problem of diagnostic disagreement between pathologists. Organizing consensus sessions between experts to reduce the variability is a difficult task. The TRIDEM platform addresses the issue to organize consensus sessions in pathology over the Internet. In this paper, we present the basis to achieve such collaborative platform. On the one hand, the platform integrates the functionalities of the IDEM consensus module that alleviates the consensus task by presenting to pathologists preliminary computed consensus through ergonomic interfaces (automatic step). On the other hand, a set of lightweight interaction tools such as vocal annotations are implemented to ease the communication between experts as they discuss a case (interactive step). The architecture of the TRIDEM platform is based on a Java-Server-Page web server that communicate with the ObjectStore PSE/PRO database used for the object storage. The HTML pages generated by the web server run Java applets to perform the different steps (automatic and interactive) of the consensus. The current limitations of the platform is to only handle a synchronous process. Moreover, improvements like re-writing the consensus workflow with a protocol such as BPML are already forecast.

LCoS-SLM technology based on Digital Electro-optics Platform and using in dynamic optics for application development

NASA Astrophysics Data System (ADS)

Tsai, Chun-Wei; Wang, Chen; Lyu, Bo-Han; Chu, Chen-Hsien

2017-08-01

Digital Electro-optics Platform is the main concept of Jasper Display Corp. (JDC) to develop various applications. These applications are based on our X-on-Silicon technologies, for example, X-on-Silicon technologies could be used on Liquid Crystal on Silicon (LCoS), Micro Light-Emitting Diode on Silicon (μLEDoS), Organic Light-Emitting Diode on Silicon (OLEDoS), and Cell on Silicon (CELLoS), etc. LCoS technology is applied to Spatial Light Modulator (SLM), Dynamic Optics, Wavelength Selective Switch (WSS), Holographic Display, Microscopy, Bio-tech, 3D Printing and Adaptive Optics, etc. In addition, μLEDoS technology is applied to Augmented Reality (AR), Head Up Display (HUD), Head-mounted Display (HMD), and Wearable Devices. Liquid Crystal on Silicon - Spatial Light Modulator (LCoSSLM) based on JDC's On-Silicon technology for both amplitude and phase modulation, have an expanding role in several optical areas where light control on a pixel-by-pixel basis is critical for optimum system performance. Combination of the advantage of hardware and software, we can establish a "dynamic optics" for the above applications or more. Moreover, through the software operation, we can control the light more flexible and easily as programmable light processor.

Designing an Online Social Support Platform Through Co-Creation with Seniors.

PubMed

Rochat, Jessica; Nap, Henk Herman; Ricci, Arnaud; Cornelisse, Lotte; Lukkien, Dirk; Lovis, Christian; Ehrler, Frédéric

2018-01-01

The high number of seniors that feels excluded of society highlights the necessity to promote active ageing. This intention can be supported through online platforms that encourage participation in social activities. The goal of the present study was to identify design principles of online support platforms for seniors through focus groups and to ideate the platform through co-creation sessions. The results show that a social platform for seniors must, among other, help to foster contact between users, and must provide services and meaningful activities. A first mock-up of the platform's design has been created based on the co-creation sessions and will be iteratively evaluated and enhanced in future studies in four countries across Europe. Our findings are in line with those of other studies demonstrating that seniors attach importance to trustworthiness and need to maintain social ties.

A novel approach for osteocalcin detection by competitive ELISA using porous silicon as a substrate.

PubMed

Rahimi, Fereshteh; Mohammadnejad Arough, Javad; Yaghoobi, Mona; Davoodi, Hadi; Sepehri, Fatemeh; Amirabadizadeh, Masood

2017-11-01

In this study, porous silicon (PSi) was utilized instead of prevalent polystyrene platforms, and its capability in biomolecule screening was examined. Here, two types of porous structure, macroporous silicon (Macro-PSi) and mesoporous silicon (Meso-PSi), were produced on silicon wafers by electrochemical etching using different electrolytes. Moreover, both kinds of fresh and oxidized PSi samples were investigated. Next, osteocalcin as a biomarker of the bone formation process was used as a model biomarker, and the colorimetric detection was performed by competitive enzyme-linked immunosorbent assay (ELISA). Both Macro-PSi and Meso-PSi substrates in the oxidized state, specifically the Meso-porous structure, were reported to have higher surface area to volume ratio, more capacitance of surface-antigen interaction, and more ability to capture antigen in comparison with the prevalent platforms. Moreover, the optical density signal of osteocalcin detected by the ELISA technique was notably higher than the common platforms. Based on the findings of this study, PSi can potentially be used in the ELISA to achieve better results and consequently more sensitivity. A further asset of incorporating such a nanometer structure in the ELISA technique is that the system response to analyte concentration could be maintained by consuming lower monoclonal antibody (or antigen) and consequently reduces the cost of the experiment. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

Monolithic silicon-photonic platforms in state-of-the-art CMOS SOI processes [Invited].

PubMed

Stojanović, Vladimir; Ram, Rajeev J; Popović, Milos; Lin, Sen; Moazeni, Sajjad; Wade, Mark; Sun, Chen; Alloatti, Luca; Atabaki, Amir; Pavanello, Fabio; Mehta, Nandish; Bhargava, Pavan

2018-05-14

Integrating photonics with advanced electronics leverages transistor performance, process fidelity and package integration, to enable a new class of systems-on-a-chip for a variety of applications ranging from computing and communications to sensing and imaging. Monolithic silicon photonics is a promising solution to meet the energy efficiency, sensitivity, and cost requirements of these applications. In this review paper, we take a comprehensive view of the performance of the silicon-photonic technologies developed to date for photonic interconnect applications. We also present the latest performance and results of our "zero-change" silicon photonics platforms in 45 nm and 32 nm SOI CMOS. The results indicate that the 45 nm and 32 nm processes provide a "sweet-spot" for adding photonic capability and enhancing integrated system applications beyond the Moore-scaling, while being able to offload major communication tasks from more deeply-scaled compute and memory chips without complicated 3D integration approaches.

IIIV/Si Nanoscale Lasers and Their Integration with Silicon Photonics

NASA Astrophysics Data System (ADS)

Bondarenko, Olesya

The rapidly evolving global information infrastructure requires ever faster data transfer within computer networks and stations. Integrated chip scale photonics can pave the way to accelerated signal manipulation and boost bandwidth capacity of optical interconnects in a compact and ergonomic arrangement. A key building block for integrated photonic circuits is an on-chip laser. In this dissertation we explore ways to reduce the physical footprint of semiconductor lasers and make them suitable for high density integration on silicon, a standard material platform for today's integrated circuits. We demonstrated the first room temperature metalo-dielectric nanolaser, sub-wavelength in all three dimensions. Next, we demonstrated a nanolaser on silicon, showing the feasibility of its integration with this platform. We also designed and realized an ultracompact feedback laser with edge-emitting structure, amenable for in-plane coupling with a standard silicon waveguide. Finally, we discuss the challenges and propose solutions for improvement of the device performance and practicality.

Vertical silicon nanowires as a universal platform for delivering biomolecules into living cells

PubMed Central

Shalek, Alex K.; Robinson, Jacob T.; Karp, Ethan S.; Lee, Jin Seok; Ahn, Dae-Ro; Yoon, Myung-Han; Sutton, Amy; Jorgolli, Marsela; Gertner, Rona S.; Gujral, Taranjit S.; MacBeath, Gavin; Yang, Eun Gyeong; Park, Hongkun

2010-01-01

A generalized platform for introducing a diverse range of biomolecules into living cells in high-throughput could transform how complex cellular processes are probed and analyzed. Here, we demonstrate spatially localized, efficient, and universal delivery of biomolecules into immortalized and primary mammalian cells using surface-modified vertical silicon nanowires. The method relies on the ability of the silicon nanowires to penetrate a cell’s membrane and subsequently release surface-bound molecules directly into the cell’s cytosol, thus allowing highly efficient delivery of biomolecules without chemical modification or viral packaging. This modality enables one to assess the phenotypic consequences of introducing a broad range of biological effectors (DNAs, RNAs, peptides, proteins, and small molecules) into almost any cell type. We show that this platform can be used to guide neuronal progenitor growth with small molecules, knock down transcript levels by delivering siRNAs, inhibit apoptosis using peptides, and introduce targeted proteins to specific organelles. We further demonstrate codelivery of siRNAs and proteins on a single substrate in a microarray format, highlighting this technology’s potential as a robust, monolithic platform for high-throughput, miniaturized bioassays. PMID:20080678

Low-loss compact multilayer silicon nitride platform for 3D photonic integrated circuits.

PubMed

Shang, Kuanping; Pathak, Shibnath; Guan, Binbin; Liu, Guangyao; Yoo, S J B

2015-08-10

We design, fabricate, and demonstrate a silicon nitride (Si(3)N(4)) multilayer platform optimized for low-loss and compact multilayer photonic integrated circuits. The designed platform, with 200 nm thick waveguide core and 700 nm interlayer gap, is compatible for active thermal tuning and applicable to realizing compact photonic devices such as arrayed waveguide gratings (AWGs). We achieve ultra-low loss vertical couplers with 0.01 dB coupling loss, multilayer crossing loss of 0.167 dB at 90° crossing angle, 50 μm bending radius, 100 × 2 μm(2) footprint, lateral misalignment tolerance up to 400 nm, and less than -52 dB interlayer crosstalk at 1550 nm wavelength. Based on the designed platform, we demonstrate a 27 × 32 × 2 multilayer star coupler.

Dorsolateral striatal lesions impair navigation based on landmark-goal vectors but facilitate spatial learning based on a “cognitive map”

PubMed Central

Poulter, Steven L.; Austen, Joe M.

2015-01-01

In three experiments, the nature of the interaction between multiple memory systems in rats solving a variation of a spatial task in the water maze was investigated. Throughout training rats were able to find a submerged platform at a fixed distance and direction from an intramaze landmark by learning a landmark-goal vector. Extramaze cues were also available for standard place learning, or “cognitive mapping,” but these cues were valid only within each session, as the position of the platform moved around the pool between sessions together with the intramaze landmark. Animals could therefore learn the position of the platform by taking the consistent vector from the landmark across sessions or by rapidly encoding the new platform position on each session with reference to the extramaze cues. Excitotoxic lesions of the dorsolateral striatum impaired vector-based learning but facilitated cognitive map-based rapid place learning when the extramaze cues were relatively poor (Experiment 1) but not when they were more salient (Experiments 2 and 3). The way the lesion effects interacted with cue availability is consistent with the idea that the memory systems involved in the current navigation task are functionally cooperative yet associatively competitive in nature. PMID:25691518

Near-infrared gallium nitride two-dimensional photonic crystal platform on silicon

NASA Astrophysics Data System (ADS)

Roland, I.; Zeng, Y.; Han, Z.; Checoury, X.; Blin, C.; El Kurdi, M.; Ghrib, A.; Sauvage, S.; Gayral, B.; Brimont, C.; Guillet, T.; Semond, F.; Boucaud, P.

2014-07-01

We demonstrate a two-dimensional free-standing gallium nitride photonic crystal platform operating around 1550 nm and fabricated on a silicon substrate. Width-modulated waveguide cavities are integrated and exhibit loaded quality factors up to 34 000 at 1575 nm. We show the resonance tunability by varying the ratio of air hole radius to periodicity, and cavity hole displacement. We deduce a ˜7.9 dB/cm linear absorption loss for the suspended nitride structure from the power dependence of the cavity in-plane transmission.

Near-infrared gallium nitride two-dimensional photonic crystal platform on silicon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roland, I.; Zeng, Y.; Han, Z.

We demonstrate a two-dimensional free-standing gallium nitride photonic crystal platform operating around 1550 nm and fabricated on a silicon substrate. Width-modulated waveguide cavities are integrated and exhibit loaded quality factors up to 34 000 at 1575 nm. We show the resonance tunability by varying the ratio of air hole radius to periodicity, and cavity hole displacement. We deduce a ∼7.9 dB/cm linear absorption loss for the suspended nitride structure from the power dependence of the cavity in-plane transmission.

Reliability of center of pressure measures within and between sessions in individuals post-stroke and healthy controls.

PubMed

Gray, Vicki L; Ivanova, Tanya D; Garland, S Jayne

2014-01-01

Knowing the reliability of the center of pressure (COP) is important for interpreting balance deficits post-stroke, especially when the balance deficits can necessitate the use of short duration trials. The novel aspect of this reliability study was to examine the center of pressure measures using two adjacent force platforms between and within sessions in stroke and controls. After stroke, it is important to understand the contribution of the paretic and non-paretic leg to the motor control of standing balance. Because there is a considerable body of knowledge on COP reliability on a single platform, we chose to examine reliability using two adjacent platforms which has not been examined previously in stroke. Twenty participants post-stroke and 22 controls performed an arm raise, load drop and quiet stance balance task while standing on two adjacent force platforms, on two separate days. Intraclass correlations coefficient (ICC2,1) and percentage standard error of measurement (SEM%) were calculated for COP velocity, ellipse area, anterior-posterior (AP) displacement, and medial-lateral (ML) displacement. Between sessions, COP velocity was the most reliable with high ICCs and low SEM% across groups and tasks and ellipse area was less reliable with low ICCs across groups and tasks. COP measures were less reliable during the arm raise than load drop post-stroke. Within session reliability was high for COP velocity and ML displacement requiring no more than six trials across tasks. The COP velocity was the most reliable measure with high ICCs between sessions and the high reliability was achieved with fewer trials in both groups in a single session. Copyright © 2014 Elsevier B.V. All rights reserved.

A Silicon-Chip Source of Bright Photon-Pair Comb

DTIC Science & Technology

2012-10-16

A silicon -chip source of bright photon-pair comb Wei C. Jiang,1, ∗ Xiyuan Lu,2, ∗ Jidong Zhang,3 Oskar Painter,4 and Qiang Lin1, 3, † 1Institute of...efficient monolithic photon-pair source for on-chip application. Here we report a device on the silicon -on-insulator platform that utilizes dramatic cavity...enhanced four-wave mixing in a high-Q silicon microdisk resonator. The device is able to produce high-purity photon pairs in a comb fashion, with an

Demonstration of slot-waveguide structures on silicon nitride / silicon oxide platform.

PubMed

Barrios, C A; Sánchez, B; Gylfason, K B; Griol, A; Sohlström, H; Holgado, M; Casquel, R

2007-05-28

We report on the first demonstration of guiding light in vertical slot-waveguides on silicon nitride/silicon oxide material system. Integrated ring resonators and Fabry-Perot cavities have been fabricated and characterized in order to determine optical features of the slot-waveguides. Group index behavior evidences guiding and confinement in the low-index slot region at O-band (1260-1370nm) telecommunication wavelengths. Propagation losses of <20 dB/cm have been measured for the transverse-electric mode of the slot-waveguides.

Hybrid integration of carbon nanotubes in silicon photonic structures

NASA Astrophysics Data System (ADS)

Durán-Valdeiglesias, E.; Zhang, W.; Alonso-Ramos, C.; Le Roux, X.; Serna, S.; Hoang, H. C.; Marris-Morini, D.; Cassan, E.; Intonti, F.; Sarti, F.; Caselli, N.; La China, F.; Gurioli, M.; Balestrieri, M.; Vivien, L.; Filoramo, A.

2017-02-01

Silicon photonics, due to its compatibility with the CMOS platform and unprecedented integration capability, has become the preferred solution for the implementation of next generation optical interconnects to accomplish high efficiency, low energy consumption, low cost and device miniaturization in one single chip. However, it is restricted by silicon itself. Silicon does not have efficient light emission or detection in the telecommunication wavelength range (1.3 μm-1.5 μm) or any electro-optic effect (i.e. Pockels effect). Hence, silicon photonic needs to be complemented with other materials for the realization of optically-active devices, including III-V for lasing and Ge for detection. The very different requirement of these materials results in complex fabrication processes that offset the cost-effectiveness of the Si photonics approach. For this purpose, carbon nanotubes (CNTs) have recently been proposed as an attractive one-dimensional light emitting material. Interestingly, semiconducting single walled CNTs (SWNTs) exhibit room-temperature photo- and electro-luminescence in the near-IR that could be exploited for the implementation of integrated nano-sources. They can also be considered for the realization of photo-detectors and optical modulators, since they rely on intrinsically fast non-linear effects, such as Stark and Kerr effect. All these properties make SWNTs ideal candidates in order to fabricate a large variety of optoelectronic devices, including near-IR sources, modulators and photodetectors on Si photonic platforms. In addition, solution processed SWNTs can be integrated on Si using spin-coating or drop-casting techniques, obviating the need of complex epitaxial growth or chip bonding approaches. Here, we report on our recent progress in the coupling of SWNTs light emission into optical resonators implemented on the silicon-on-insulator (SOI) platform. .

Silicon Integrated Optics: Fabrication and Characterization

NASA Astrophysics Data System (ADS)

Shearn, Michael Joseph, II

For decades, the microelectronics industry has sought integration and miniaturization as canonized in Moore's Law, and has continued doubling transistor density about every two years. However, further miniaturization of circuit elements is creating a bandwidth problem as chip interconnect wires shrink as well. A potential solution is the creation of an on-chip optical network with low delays that would be impossible to achieve using metal buses. However, this technology requires integrating optics with silicon microelectronics. The lack of efficient silicon optical sources has stymied efforts of an all-Si optical platform. Instead, the integration of efficient emitter materials, such as III-V semiconductors, with Si photonic structures is a low-cost, CMOS-compatible alternative platform. This thesis focuses on making and measuring on-chip photonic structures suitable for on-chip optical networking. The first part of the thesis assesses processing techniques of silicon and other semiconductor materials. Plasmas for etching and surface modification are described and used to make bonded, hybrid Si/III-V structures. Additionally, a novel masking method using gallium implantation into silicon for pattern definition is characterized. The second part of the thesis focuses on demonstrations of fabricated optical structures. A dense array of silicon devices is measured, consisting of fully-etched grating couplers, low-loss waveguides and ring resonators. Finally, recent progress in the Si/III-V hybrid system is discussed. Supermode control of devices is described, which uses changing Si waveguide width to control modal overlap with the gain material. Hybrid Si/III-V, Fabry-Perot evanescent lasers are demonstrated, utilizing a CMOS-compatible process suitable for integration on in electronics platforms. Future prospects and ultimate limits of Si devices and the hybrid Si/III-V system are also considered.

Lasing in silicon–organic hybrid waveguides

PubMed Central

Korn, Dietmar; Lauermann, Matthias; Koeber, Sebastian; Appel, Patrick; Alloatti, Luca; Palmer, Robert; Dumon, Pieter; Freude, Wolfgang; Leuthold, Juerg; Koos, Christian

2016-01-01

Silicon photonics enables large-scale photonic–electronic integration by leveraging highly developed fabrication processes from the microelectronics industry. However, while a rich portfolio of devices has already been demonstrated on the silicon platform, on-chip light sources still remain a key challenge since the indirect bandgap of the material inhibits efficient photon emission and thus impedes lasing. Here we demonstrate a class of infrared lasers that can be fabricated on the silicon-on-insulator (SOI) integration platform. The lasers are based on the silicon–organic hybrid (SOH) integration concept and combine nanophotonic SOI waveguides with dye-doped organic cladding materials that provide optical gain. We demonstrate pulsed room-temperature lasing with on-chip peak output powers of up to 1.1 W at a wavelength of 1,310 nm. The SOH approach enables efficient mass-production of silicon photonic light sources emitting in the near infrared and offers the possibility of tuning the emission wavelength over a wide range by proper choice of dye materials and resonator geometry. PMID:26949229

Electrically Conductive and Optically Active Porous Silicon Nanowires

PubMed Central

Qu, Yongquan; Liao, Lei; Li, Yujing; Zhang, Hua; Huang, Yu; Duan, Xiangfeng

2009-01-01

We report the synthesis of vertical silicon nanowire array through a two-step metal-assisted chemical etching of highly doped n-type silicon (100) wafers in a solution of hydrofluoric acid and hydrogen peroxide. The morphology of the as-grown silicon nanowires is tunable from solid nonporous nanowires, nonporous/nanoporous core/shell nanowires, and entirely nanoporous nanowires by controlling the hydrogen peroxide concentration in the etching solution. The porous silicon nanowires retain the single crystalline structure and crystallographic orientation of the starting silicon wafer, and are electrically conductive and optically active with visible photoluminescence. The combination of electronic and optical properties in the porous silicon nanowires may provide a platform for the novel optoelectronic devices for energy harvesting, conversion and biosensing. PMID:19807130

A silicon Brillouin laser

NASA Astrophysics Data System (ADS)

Otterstrom, Nils T.; Behunin, Ryan O.; Kittlaus, Eric A.; Wang, Zheng; Rakich, Peter T.

2018-06-01

Brillouin laser oscillators offer powerful and flexible dynamics as the basis for mode-locked lasers, microwave oscillators, and optical gyroscopes in a variety of optical systems. However, Brillouin interactions are markedly weak in conventional silicon photonic waveguides, stifling progress toward silicon-based Brillouin lasers. The recent advent of hybrid photonic-phononic waveguides has revealed Brillouin interactions to be one of the strongest and most tailorable nonlinearities in silicon. In this study, we have harnessed these engineered nonlinearities to demonstrate Brillouin lasing in silicon. Moreover, we show that this silicon-based Brillouin laser enters a regime of dynamics in which optical self-oscillation produces phonon linewidth narrowing. Our results provide a platform to develop a range of applications for monolithic integration within silicon photonic circuits.

Silicon photonics and challenges for fabrication

NASA Astrophysics Data System (ADS)

Feilchenfeld, N. B.; Nummy, K.; Barwicz, T.; Gill, D.; Kiewra, E.; Leidy, R.; Orcutt, J. S.; Rosenberg, J.; Stricker, A. D.; Whiting, C.; Ayala, J.; Cucci, B.; Dang, D.; Doan, T.; Ghosal, M.; Khater, M.; McLean, K.; Porth, B.; Sowinski, Z.; Willets, C.; Xiong, C.; Yu, C.; Yum, S.; Giewont, K.; Green, W. M. J.

2017-03-01

Silicon photonics is rapidly becoming the key enabler for meeting the future data speed and volume required by the Internet of Things. A stable manufacturing process is needed to deliver cost and yield expectations to the technology marketplace. We present the key challenges and technical results from both 200mm and 300mm facilities for a silicon photonics fabrication process which includes monolithic integration with CMOS. This includes waveguide patterning, optical proximity correction for photonic devices, silicon thickness uniformity and thick material patterning for passive fiber to waveguide alignment. The device and process metrics show that the transfer of the silicon photonics process from 200mm to 300mm will provide a stable high volume manufacturing platform for silicon photonics designs.

Highly Sensitive Bulk Silicon Chemical Sensors with Sub-5 nm Thin Charge Inversion Layers.

PubMed

Fahad, Hossain M; Gupta, Niharika; Han, Rui; Desai, Sujay B; Javey, Ali

2018-03-27

There is an increasing demand for mass-producible, low-power gas sensors in a wide variety of industrial and consumer applications. Here, we report chemical-sensitive field-effect-transistors (CS-FETs) based on bulk silicon wafers, wherein an electrostatically confined sub-5 nm thin charge inversion layer is modulated by chemical exposure to achieve a high-sensitivity gas-sensing platform. Using hydrogen sensing as a "litmus" test, we demonstrate large sensor responses (>1000%) to 0.5% H 2 gas, with fast response (<60 s) and recovery times (<120 s) at room temperature and low power (<50 μW). On the basis of these performance metrics as well as standardized benchmarking, we show that bulk silicon CS-FETs offer similar or better sensing performance compared to emerging nanostructures semiconductors while providing a highly scalable and manufacturable platform.

Enabling chip-scale trace gas sensing systems with silicon photonics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, William

Tunable laser trace-gas spectroscopy has been effectively used in both environmental and medical applications, for its sensitivity and specificity. We’ll describe how contemporary silicon photonics manufacturing and assembly are leveraged for a cost-effective miniaturized spectroscopic sensor platform, and outline uses in fugitive methane emissions monitoring.

The mid-IR silicon photonics sensor platform (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kimerling, Lionel; Hu, Juejun; Agarwal, Anuradha M.

2017-02-01

Advances in integrated silicon photonics are enabling highly connected sensor networks that offer sensitivity, selectivity and pattern recognition. Cost, performance and the evolution path of the so-called `Internet of Things' will gate the proliferation of these networks. The wavelength spectral range of 3-8um, commonly known as the mid-IR, is critical to specificity for sensors that identify materials by detection of local vibrational modes, reflectivity and thermal emission. For ubiquitous sensing applications in this regime, the sensors must move from premium to commodity level manufacturing volumes and cost. Scaling performance/cost is critically dependent on establishing a minimum set of platform attributes for point, wearable, and physical sensing. Optical sensors are ideal for non-invasive applications. Optical sensor device physics involves evanescent or intra-cavity structures for applied to concentration, interrogation and photo-catalysis functions. The ultimate utility of a platform is dependent on sample delivery/presentation modalities; system reset, recalibration and maintenance capabilities; and sensitivity and selectivity performance. The attributes and performance of a unified Glass-on-Silicon platform has shown good prospects for heterogeneous integration on materials and devices using a low cost process flow. Integrated, single mode, silicon photonic platforms offer significant performance and cost advantages, but they require discovery and qualification of new materials and process integration schemes for the mid-IR. Waveguide integrated light sources based on rare earth dopants and Ge-pumped frequency combs have promise. Optical resonators and waveguide spirals can enhance sensitivity. PbTe materials are among the best choices for a standard, waveguide integrated photodetector. Chalcogenide glasses are capable of transmitting mid-IR signals with high transparency. Integrated sensor case studies of i) high sensitivity analyte detection in solution; ii) gas sensing in air and iii) on-chip spectrometry provide good insight into the tradeoffs being made en route to ubiquitous sensor deployment in an Internet of Things.

A Highly Sensitive Porous Silicon (P-Si)-Based Human Kallikrein 2 (hK2) Immunoassay Platform toward Accurate Diagnosis of Prostate Cancer

PubMed Central

Lee, Sang Wook; Hosokawa, Kazuo; Kim, Soyoun; Jeong, Ok Chan; Lilja, Hans; Laurell, Thomas; Maeda, Mizuo

2015-01-01

Levels of total human kallikrein 2 (hK2), a protein involved the pathology of prostate cancer (PCa), could be used as a biomarker to aid in the diagnosis of this disease. In this study, we report on a porous silicon antibody immunoassay platform for the detection of serum levels of total hK2. The surface of porous silicon has a 3-dimensional macro- and nanoporous structure, which offers a large binding capacity for capturing probe molecules. The tailored pore size of the porous silicon also allows efficient immobilization of antibodies by surface adsorption, and does not require chemical immobilization. Monoclonal hK2 capture antibody (6B7) was dispensed onto P-Si chip using a piezoelectric dispenser. In total 13 × 13 arrays (169 spots) were spotted on the chip with its single spot volume of 300 pL. For an optimization of capture antibody condition, we firstly performed an immunoassay of the P-Si microarray under a titration series of hK2 in pure buffer (PBS) at three different antibody densities (75, 100 and 145 µg/mL). The best performance of the microarray platform was seen at 100 µg/mL of the capture antibody concentration (LOD was 100 fg/mL). The platform then was subsequently evaluated for a titration series of serum-spiked hK2 samples. The developed platform utilizes only 15 µL of serum per test and the total assay time is about 3 h, including immobilization of the capture antibody. The detection limit of the hK2 assay was 100 fg/mL in PBS buffer and 1 pg/mL in serum with a dynamic range of 106 (10−4 to 102 ng/mL). PMID:26007739

A Highly Sensitive Porous Silicon (P-Si)-Based Human Kallikrein 2 (hK2) Immunoassay Platform toward Accurate Diagnosis of Prostate Cancer.

PubMed

Lee, Sang Wook; Hosokawa, Kazuo; Kim, Soyoun; Jeong, Ok Chan; Lilja, Hans; Laurell, Thomas; Maeda, Mizuo

2015-05-22

Levels of total human kallikrein 2 (hK2), a protein involved the pathology of prostate cancer (PCa), could be used as a biomarker to aid in the diagnosis of this disease. In this study, we report on a porous silicon antibody immunoassay platform for the detection of serum levels of total hK2. The surface of porous silicon has a 3-dimensional macro- and nanoporous structure, which offers a large binding capacity for capturing probe molecules. The tailored pore size of the porous silicon also allows efficient immobilization of antibodies by surface adsorption, and does not require chemical immobilization. Monoclonal hK2 capture antibody (6B7) was dispensed onto P-Si chip using a piezoelectric dispenser. In total 13 × 13 arrays (169 spots) were spotted on the chip with its single spot volume of 300 pL. For an optimization of capture antibody condition, we firstly performed an immunoassay of the P-Si microarray under a titration series of hK2 in pure buffer (PBS) at three different antibody densities (75, 100 and 145 µg/mL). The best performance of the microarray platform was seen at 100 µg/mL of the capture antibody concentration (LOD was 100 fg/mL). The platform then was subsequently evaluated for a titration series of serum-spiked hK2 samples. The developed platform utilizes only 15 µL of serum per test and the total assay time is about 3 h, including immobilization of the capture antibody. The detection limit of the hK2 assay was 100 fg/mL in PBS buffer and 1 pg/mL in serum with a dynamic range of 106 (10(-4) to 10(2) ng/mL).

Silicon photonics integrated circuits: a manufacturing platform for high density, low power optical I/O's.

PubMed

Absil, Philippe P; Verheyen, Peter; De Heyn, Peter; Pantouvaki, Marianna; Lepage, Guy; De Coster, Jeroen; Van Campenhout, Joris

2015-04-06

Silicon photonics integrated circuits are considered to enable future computing systems with optical input-outputs co-packaged with CMOS chips to circumvent the limitations of electrical interfaces. In this paper we present the recent progress made to enable dense multiplexing by exploiting the integration advantage of silicon photonics integrated circuits. We also discuss the manufacturability of such circuits, a key factor for a wide adoption of this technology.

High-efficiency fiber-to-chip grating couplers realized using an advanced CMOS-compatible silicon-on-insulator platform.

PubMed

Vermeulen, D; Selvaraja, S; Verheyen, P; Lepage, G; Bogaerts, W; Absil, P; Van Thourhout, D; Roelkens, G

2010-08-16

A new generation of Silicon-on-Insulator fiber-to-chip grating couplers which use a silicon overlay to enhance the directionality and thereby the coupling efficiency is presented. Devices are realized on a 200 mm wafer in a CMOS pilot line. The fabricated fiber couplers show a coupling efficiency of -1.6 dB and a 3 dB bandwidth of 80 nm.

Proceedings of the 1999 Oil and Gas Conference: Technology Options for Producer Survival

DOE Office of Scientific and Technical Information (OSTI.GOV)

None available

2000-04-12

The 1999 Oil & Gas Conference was cosponsored by the U.S. Department of Energy (DOE), Office of Fossil Energy, Federal Energy Technology Center (FETC) and National Petroleum Technology Office (NPTO) on June 28 to 30 in Dallas, Texas. The Oil & Gas Conference theme, Technology Options for Producer Survival, reflects the need for development and implementation of new technologies to ensure an affordable, reliable energy future. The conference was attended by nearly 250 representatives from industry, academia, national laboratories, DOE, and other Government agencies. Three preconference workshops (Downhole Separation Technologies: Is it Applicable for Your Operations, Exploring and developing Naturallymore » Fractured Low-Permeability Gas Reservoirs from the Rocky Mountains to the Austin Chalk, and Software Program Applications) were held. The conference agenda included an opening plenary session, three platform sessions (Sessions 2 and 3 were split into 2 concurrent topics), and a poster presentation reception. The platform session topics were Converting Your Resources Into Reserves (Sessions 1 and 2A), Clarifying Your Subsurface Vision (Session 2B), and High Performance, Cost Effective Drilling, Completion, Stimulation Technologies (Session 3B). In total, there were 5 opening speakers, 30 presenters, and 16 poster presentations.« less

Proceedings of the Flat-plate Solar Array Project Research Forum on High-efficiency Crystalline Silicon Solar Cells

NASA Technical Reports Server (NTRS)

Kachare, R.

1985-01-01

The high-efficiency crystalline silicon solar cells research forum addressed high-efficiency concepts, surface-interface effects, bulk effects, modeling and device processing. The topics were arranged into six interactive sessions, which focused on the state-of-the-art of device structures, identification of barriers to achieve high-efficiency cells and potential ways to overcome these barriers.

Silicon Modulators, Switches and Sub-systems for Optical Interconnect

NASA Astrophysics Data System (ADS)

Li, Qi

Silicon photonics is emerging as a promising platform for manufacturing and integrating photonic devices for light generation, modulation, switching and detection. The compatibility with existing CMOS microelectronic foundries and high index contrast in silicon could enable low cost and high performance photonic systems, which find many applications in optical communication, data center networking and photonic network-on-chip. This thesis first develops and demonstrates several experimental work on high speed silicon modulators and switches with record performance and novel functionality. A 8x40 Gb/s transmitter based on silicon microrings is first presented. Then an end-to-end link using microrings for Binary Phase Shift Keying (BPSK) modulation and demodulation is shown, and its performance with conventional BPSK modulation/ demodulation techniques is compared. Next, a silicon traveling-wave Mach- Zehnder modulator is demonstrated at data rate up to 56 Gb/s for OOK modulation and 48 Gb/s for BPSK modulation, showing its capability at high speed communication systems. Then a single silicon microring is shown with 2x2 full crossbar switching functionality, enabling optical interconnects with ultra small footprint. Then several other experiments in the silicon platform are presented, including a fully integrated in-band Optical Signal to Noise Ratio (OSNR) monitor, characterization of optical power upper bound in a silicon microring modulator, and wavelength conversion in a dispersion-engineered waveguide. The last part of this thesis is on network-level application of photonics, specically a broadcast-and-select network based on star coupler is introduced, and its scalability performance is studied. Finally a novel switch architecture for data center networks is discussed, and its benefits as a disaggregated network are presented.

Thiolene and SIFEL-based Microfluidic Platforms for Liquid-Liquid Extraction

PubMed Central

Goyal, Sachit; Desai, Amit V.; Lewis, Robert W.; Ranganathan, David R.; Li, Hairong; Zeng, Dexing; Reichert, David E.; Kenis, Paul J.A.

2014-01-01

Microfluidic platforms provide several advantages for liquid-liquid extraction (LLE) processes over conventional methods, for example with respect to lower consumption of solvents and enhanced extraction efficiencies due to the inherent shorter diffusional distances. Here, we report the development of polymer-based parallel-flow microfluidic platforms for LLE. To date, parallel-flow microfluidic platforms have predominantly been made out of silicon or glass due to their compatibility with most organic solvents used for LLE. Fabrication of silicon and glass-based LLE platforms typically requires extensive use of photolithography, plasma or laser-based etching, high temperature (anodic) bonding, and/or wet etching with KOH or HF solutions. In contrast, polymeric microfluidic platforms can be fabricated using less involved processes, typically photolithography in combination with replica molding, hot embossing, and/or bonding at much lower temperatures. Here we report the fabrication and testing of microfluidic LLE platforms comprised of thiolene or a perfluoropolyether-based material, SIFEL, where the choice of materials was mainly guided by the need for solvent compatibility and fabrication amenability. Suitable designs for polymer-based LLE platforms that maximize extraction efficiencies within the constraints of the fabrication methods and feasible operational conditions were obtained using analytical modeling. To optimize the performance of the polymer-based LLE platforms, we systematically studied the effect of surface functionalization and of microstructures on the stability of the liquid-liquid interface and on the ability to separate the phases. As demonstrative examples, we report (i) a thiolene-based platform to determine the lipophilicity of caffeine, and (ii) a SIFEL-based platform to extract radioactive copper from an acidic aqueous solution. PMID:25246730

Silicon nanostructures for cancer diagnosis and therapy.

PubMed

Peng, Fei; Cao, Zhaohui; Ji, Xiaoyuan; Chu, Binbin; Su, Yuanyuan; He, Yao

2015-01-01

The emergence of nanotechnology suggests new and exciting opportunities for early diagnosis and therapy of cancer. During the recent years, silicon-based nanomaterials featuring unique properties have received great attention, showing high promise for myriad biological and biomedical applications. In this review, we will particularly summarize latest representative achievements on the development of silicon nanostructures as a powerful platform for cancer early diagnosis and therapy. First, we introduce the silicon nanomaterial-based biosensors for detecting cancer markers (e.g., proteins, tumor-suppressor genes and telomerase activity, among others) with high sensitivity and selectivity under molecular level. Then, we summarize in vitro and in vivo applications of silicon nanostructures as efficient nanoagents for cancer therapy. Finally, we discuss the future perspective of silicon nanostructures for cancer diagnosis and therapy.

Ultra-low crosstalk, CMOS compatible waveguide crossings for densely integrated photonic interconnection networks.

PubMed

Jones, Adam M; DeRose, Christopher T; Lentine, Anthony L; Trotter, Douglas C; Starbuck, Andrew L; Norwood, Robert A

2013-05-20

We explore the design space for optimizing CMOS compatible waveguide crossings on a silicon photonics platform. This paper presents simulated and experimental excess loss and crosstalk suppression data for vertically integrated silicon nitride over silicon-on-insulator waveguide crossings. Experimental results show crosstalk suppression exceeding -49/-44 dB with simulation results as low as -65/-60 dB for the TE/TM mode in a waveguide crossing with a 410 nm vertical gap.

Experimental demonstration of two-dimensional hybrid waveguide-integrated plasmonic crystals on silicon-on-insulator platform

NASA Astrophysics Data System (ADS)

Ren, Guanghui; Yudistira, Didit; Nguyen, Thach G.; Khodasevych, Iryna; Schoenhardt, Steffen; Berean, Kyle J.; Hamm, Joachim M.; Hess, Ortwin; Mitchell, Arnan

2017-07-01

Nanoscale plasmonic structures can offer unique functionality due to extreme sub-wavelength optical confinement, but the realization of complex plasmonic circuits is hampered by high propagation losses. Hybrid approaches can potentially overcome this limitation, but only few practical approaches based on either single or few element arrays of nanoantennas on dielectric nanowire have been experimentally demonstrated. In this paper, we demonstrate a two dimensional hybrid photonic plasmonic crystal interfaced with a standard silicon photonic platform. Off resonance, we observe low loss propagation through our structure, while on resonance we observe strong propagation suppression and intense concentration of light into a dense lattice of nanoscale hot-spots on the surface providing clear evidence of a hybrid photonic plasmonic crystal bandgap. This fully integrated approach is compatible with established silicon-on-insulator (SOI) fabrication techniques and constitutes a significant step toward harnessing plasmonic functionality within SOI photonic circuits.

Pushing the limits of CMOS optical parametric amplifiers with USRN:Si7N3 above the two-photon absorption edge

PubMed Central

Ooi, K. J. A.; Ng, D. K. T.; Wang, T.; Chee, A. K. L.; Ng, S. K.; Wang, Q.; Ang, L. K.; Agarwal, A. M.; Kimerling, L. C.; Tan, D. T. H.

2017-01-01

CMOS platforms operating at the telecommunications wavelength either reside within the highly dissipative two-photon regime in silicon-based optical devices, or possess small nonlinearities. Bandgap engineering of non-stoichiometric silicon nitride using state-of-the-art fabrication techniques has led to our development of USRN (ultra-silicon-rich nitride) in the form of Si7N3, that possesses a high Kerr nonlinearity (2.8 × 10−13 cm2 W−1), an order of magnitude larger than that in stoichiometric silicon nitride. Here we experimentally demonstrate high-gain optical parametric amplification using USRN, which is compositionally tailored such that the 1,550 nm wavelength resides above the two-photon absorption edge, while still possessing large nonlinearities. Optical parametric gain of 42.5 dB, as well as cascaded four-wave mixing with gain down to the third idler is observed and attributed to the high photon efficiency achieved through operating above the two-photon absorption edge, representing one of the largest optical parametric gains to date on a CMOS platform. PMID:28051064

Ultra-large nonlinear parameter in graphene-silicon waveguide structures.

PubMed

Donnelly, Christine; Tan, Dawn T H

2014-09-22

Mono-layer graphene integrated with optical waveguides is studied for the purpose of maximizing E-field interaction with the graphene layer, for the generation of ultra-large nonlinear parameters. It is shown that the common approach used to minimize the waveguide effective modal area does not accurately predict the configuration with the maximum nonlinear parameter. Both photonic and plasmonic waveguide configurations and graphene integration techniques realizable with today's fabrication tools are studied. Importantly, nonlinear parameters exceeding 10(4) W(-1)/m, two orders of magnitude larger than that in silicon on insulator waveguides without graphene, are obtained for the quasi-TE mode in silicon waveguides incorporating mono-layer graphene in the evanescent part of the optical field. Dielectric loaded surface plasmon polariton waveguides incorporating mono-layer graphene are observed to generate nonlinear parameters as large as 10(5) W(-1)/m, three orders of magnitude larger than that in silicon on insulator waveguides without graphene. The ultra-large nonlinear parameters make such waveguides promising platforms for nonlinear integrated optics at ultra-low powers, and for previously unobserved nonlinear optical effects to be studied in a waveguide platform.

Multiplexed evaluation of capture agent binding kinetics using arrays of silicon photonic microring resonators.

PubMed

Byeon, Ji-Yeon; Bailey, Ryan C

2011-09-07

High affinity capture agents recognizing biomolecular targets are essential in the performance of many proteomic detection methods. Herein, we report the application of a label-free silicon photonic biomolecular analysis platform for simultaneously determining kinetic association and dissociation constants for two representative protein capture agents: a thrombin-binding DNA aptamer and an anti-thrombin monoclonal antibody. The scalability and inherent multiplexing capability of the technology make it an attractive platform for simultaneously evaluating the binding characteristics of multiple capture agents recognizing the same target antigen, and thus a tool complementary to emerging high-throughput capture agent generation strategies.

Porous silicon advances in drug delivery and immunotherapy

PubMed Central

Savage, D; Liu, X; Curley, S; Ferrari, M; Serda, RE

2013-01-01

Biomedical applications of porous silicon include drug delivery, imaging, diagnostics and immunotherapy. This review summarizes new silicon particle fabrication techniques, dynamics of cellular transport, advances in the multistage vector approach to drug delivery, and the use of porous silicon as immune adjuvants. Recent findings support superior therapeutic efficacy of the multistage vector approach over single particle drug delivery systems in mouse models of ovarian and breast cancer. With respect to vaccine development, multivalent presentation of pathogen-associated molecular patterns on the particle surface creates powerful platforms for immunotherapy, with the porous matrix able to carry both antigens and immune modulators. PMID:23845260

Low-loss slot waveguides with silicon (111) surfaces realized using anisotropic wet etching

NASA Astrophysics Data System (ADS)

Debnath, Kapil; Khokhar, Ali; Boden, Stuart; Arimoto, Hideo; Oo, Swe; Chong, Harold; Reed, Graham; Saito, Shinichi

2016-11-01

We demonstrate low-loss slot waveguides on silicon-on-insulator (SOI) platform. Waveguides oriented along the (11-2) direction on the Si (110) plane were first fabricated by a standard e-beam lithography and dry etching process. A TMAH based anisotropic wet etching technique was then used to remove any residual side wall roughness. Using this fabrication technique propagation loss as low as 3.7dB/cm was realized in silicon slot waveguide for wavelengths near 1550nm. We also realized low propagation loss of 1dB/cm for silicon strip waveguides.

DAPHNE silicon photonics technological platform for research and development on WDM applications

NASA Astrophysics Data System (ADS)

Baudot, Charles; Fincato, Antonio; Fowler, Daivid; Perez-Galacho, Diego; Souhaité, Aurélie; Messaoudène, Sonia; Blanc, Romuald; Richard, Claire; Planchot, Jonathan; De-Buttet, Come; Orlando, Bastien; Gays, Fabien; Mezzomo, Cécilia; Bernard, Emilie; Marris-Morini, Delphine; Vivien, Laurent; Kopp, Christophe; Boeuf, Frédéric

2016-05-01

A new technological platform aimed at making prototypes and feasibility studies has been setup at STMicroelectronics using 300mm wafer foundry facilities. The technology, called DAPHNE (Datacom Advanced PHotonic Nanoscale Environment), is devoted at developing and evaluating new devices and sub-systems in particular for wavelength division multiplexing (WDM) applications and ring resonator based applications. Developed in the course of PLAT4MFP7 European project, DAPHNE is a flexible platform that fits perfectly R&D needs. The fabrication flow enables the processing of photonic integrated circuits using a silicon-on-insulator (SOI) of 300nm, partial etches of 150nm and 50nm and a total silicon etching. Consequently, two varieties of rib waveguides and one strip waveguide can be fabricated simultaneously with auto-alignment properties. The process variability on the 150nm partially etched silicon and the thin 50nm slab region are both less than 6 nm. Using a variety of different implantation configurations and a back-end of line of 5 metal layers, active devices are fabricated both in germanium and silicon. An available far back-end of line process consists of making 20 μm diameter copper posts on top of the electrical pads so that an electronic integrated circuit can be bonded on top the photonic die by 3D integration. Besides having those fabrication process options, DAPHNE is equipped with a library of standard cells for optical routing and multiplexing. Moreover, typical Mach-Zehnder modulators based on silicon pn junctions are also available for optical signal modulation. To achieve signal detection, germanium photodetectors also exist as standard cells. The measured single-mode propagation losses are 3.5 dB/cm for strip, 3.7 dB/cm for deep-rib (50nm slab) and 1.4 dB/cm for standard rib (150nm slab) waveguides. Transition tapers between different waveguide structures are as low as 0.006 dB.

Development of an Automated Microfluidic Reaction Platform for Multidimensional Screening: Reaction Discovery Employing Bicyclo[3.2.1]octanoid Scaffolds

PubMed Central

Goodell, John R.; McMullen, Jonathan P.; Zaborenko, Nikolay; Maloney, Jason R.; Ho, Chuan-Xing; Jensen, Klavs F.; Porco, John A.

2010-01-01

An automated, silicon-based microreactor system has been developed for rapid, low-volume, multidimensional reaction screening. Use of the microfluidic platform to identify transformations of densely functionalized bicyclo[3.2.1]octanoid scaffolds will be described. PMID:20560568

Room temperature multiplexed gas sensing using chemical-sensitive 3.5-nm-thin silicon transistors.

PubMed

Fahad, Hossain Mohammad; Shiraki, Hiroshi; Amani, Matin; Zhang, Chuchu; Hebbar, Vivek Srinivas; Gao, Wei; Ota, Hiroki; Hettick, Mark; Kiriya, Daisuke; Chen, Yu-Ze; Chueh, Yu-Lun; Javey, Ali

2017-03-01

There is great interest in developing a low-power gas sensing technology that can sensitively and selectively quantify the chemical composition of a target atmosphere. Nanomaterials have emerged as extremely promising candidates for this technology due to their inherent low-dimensional nature and high surface-to-volume ratio. Among these, nanoscale silicon is of great interest because pristine silicon is largely inert on its own in the context of gas sensing, unless functionalized with an appropriate gas-sensitive material. We report a chemical-sensitive field-effect transistor (CS-FET) platform based on 3.5-nm-thin silicon channel transistors. Using industry-compatible processing techniques, the conventional electrically active gate stack is replaced by an ultrathin chemical-sensitive layer that is electrically nonconducting and coupled to the 3.5-nm-thin silicon channel. We demonstrate a low-power, sensitive, and selective multiplexed gas sensing technology using this platform by detecting H 2 S, H 2 , and NO 2 at room temperature for environment, health, and safety in the oil and gas industry, offering significant advantages over existing technology. Moreover, the system described here can be readily integrated with mobile electronics for distributed sensor networks in environmental pollution mapping and personal air-quality monitors.

Room temperature multiplexed gas sensing using chemical-sensitive 3.5-nm-thin silicon transistors

PubMed Central

Fahad, Hossain Mohammad; Shiraki, Hiroshi; Amani, Matin; Zhang, Chuchu; Hebbar, Vivek Srinivas; Gao, Wei; Ota, Hiroki; Hettick, Mark; Kiriya, Daisuke; Chen, Yu-Ze; Chueh, Yu-Lun; Javey, Ali

2017-01-01

There is great interest in developing a low-power gas sensing technology that can sensitively and selectively quantify the chemical composition of a target atmosphere. Nanomaterials have emerged as extremely promising candidates for this technology due to their inherent low-dimensional nature and high surface-to-volume ratio. Among these, nanoscale silicon is of great interest because pristine silicon is largely inert on its own in the context of gas sensing, unless functionalized with an appropriate gas-sensitive material. We report a chemical-sensitive field-effect transistor (CS-FET) platform based on 3.5-nm-thin silicon channel transistors. Using industry-compatible processing techniques, the conventional electrically active gate stack is replaced by an ultrathin chemical-sensitive layer that is electrically nonconducting and coupled to the 3.5-nm-thin silicon channel. We demonstrate a low-power, sensitive, and selective multiplexed gas sensing technology using this platform by detecting H2S, H2, and NO2 at room temperature for environment, health, and safety in the oil and gas industry, offering significant advantages over existing technology. Moreover, the system described here can be readily integrated with mobile electronics for distributed sensor networks in environmental pollution mapping and personal air-quality monitors. PMID:28378017

Linewidth Narrowing and Purcell Enhancement in Photonic Crystal Cavities on an Er-Doped Silicon Nitride Platform

DTIC Science & Technology

2010-02-01

Low noise superconducting single photon detectors on silicon,” Appl. Phys. Lett. 93, 131101 (2008). 20. M. T. Tanner, C. M. Natarajan, V. K... wavelength sensitivity in NbTiN superconducting nanowire single-photon detectors fabricated on oxidized silicon substrates,” Proceedings of Single...cavity resonance wavelength and Q-factor for the PC cavity are shown in Figure 3. The data are taken both at low (0.050 mW) pump power and high (30 mW

Opportunities of CMOS-MEMS integration through LSI foundry and open facility

NASA Astrophysics Data System (ADS)

Mita, Yoshio; Lebrasseur, Eric; Okamoto, Yuki; Marty, Frédéfic; Setoguchi, Ryota; Yamada, Kentaro; Mori, Isao; Morishita, Satoshi; Imai, Yoshiaki; Hosaka, Kota; Hirakawa, Atsushi; Inoue, Shu; Kubota, Masanori; Denoual, Matthieu

2017-06-01

Since the 2000s, several countries have established micro- and nanofabrication platforms for the research and education community as national projects. By combining such platforms with VLSI multichip foundry services, various integrated devices, referred to as “CMOS-MEMS”, can be realized without constructing an entire cleanroom. In this paper, we summarize MEMS-last postprocess schemes for CMOS devices on a bulk silicon wafer as well as on a silicon-on-insulator (SOI) wafer using an open-access cleanroom of the Nanotechnology Platform of MEXT Japan. The integration devices presented in this article are free-standing structures and postprocess isolated LSI devices. Postprocess issues are identified with their solutions, such as the reactive ion etching (RIE) lag for dry release and the impact of the deep RIE (DRIE) postprocess on transistor characteristics. Integration with nonsilicon materials is proposed as one of the future directions.

Thermal and Power Challenges in High Performance Computing Systems

NASA Astrophysics Data System (ADS)

Natarajan, Venkat; Deshpande, Anand; Solanki, Sudarshan; Chandrasekhar, Arun

2009-05-01

This paper provides an overview of the thermal and power challenges in emerging high performance computing platforms. The advent of new sophisticated applications in highly diverse areas such as health, education, finance, entertainment, etc. is driving the platform and device requirements for future systems. The key ingredients of future platforms are vertically integrated (3D) die-stacked devices which provide the required performance characteristics with the associated form factor advantages. Two of the major challenges to the design of through silicon via (TSV) based 3D stacked technologies are (i) effective thermal management and (ii) efficient power delivery mechanisms. Some of the key challenges that are articulated in this paper include hot-spot superposition and intensification in a 3D stack, design/optimization of thermal through silicon vias (TTSVs), non-uniform power loading of multi-die stacks, efficient on-chip power delivery, minimization of electrical hotspots etc.

Interferometer immunosensor based on porous silicon for determining alpha-fetoprotein

NASA Astrophysics Data System (ADS)

Lv, Xiaoyi; Jiang, Jing; Lv, Guodong; Mo, Jiaqing; Jia, Zhenhong

2016-10-01

An increased level of alpha-fetoprotein ( AFP) in the blood may be a sign of liver cancer. Porous silicon based optical microcavities structure is prepared as a label-free immunosensor platform for detecting AFP. After the antigen-antibody reaction, it is monitored that the red shift of the reflection spectrum of the immunosensor increases

Hybrid Silicon Photonic Integration using Quantum Well Intermixing

NASA Astrophysics Data System (ADS)

Jain, Siddharth R.

With the push for faster data transfer across all domains of telecommunication, optical interconnects are transitioning into shorter range applications such as in data centers and personal computing. Silicon photonics, with its economic advantages of leveraging well-established silicon manufacturing facilities, is considered the most promising approach to further scale down the cost and size of optical interconnects for chip-to-chip communication. Intrinsic properties of silicon however limit its ability to generate and modulate light, both of which are key to realizing on-chip optical data transfer. The hybrid silicon approach directly addresses this problem by using molecularly bonded III-V epitaxial layers on silicon for optical gain and absorption. This technology includes direct transfer of III-V wafer to a pre-patterned silicon-on-insulator wafer. Several discrete devices for light generation, modulation, amplification and detection have already been demonstrated on this platform. As in the case of electronics, multiple photonic elements can be integrated on a single chip to improve performance and functionality. However, scalable photonic integration requires the ability to control the bandgap for individual devices along with design changes to simplify fabrication. In the research presented here, quantum well intermixing is used as a technique to define multiple bandgaps for integration on the hybrid silicon platform. Implantation enhanced disordering is used to generate four bandgaps spread over 120+ nm. By combining these selectively intermixed III-V layers with pre-defined gratings and waveguides on silicon, we fabricate distributed feedback, distributed Bragg reflector, Fabry-Perot and mode-locked lasers along with photodetectors, electro-absorption modulators and other test structures, all on a single chip. We demonstrate a broadband laser source with continuous-wave operational lasers over a 200 nm bandwidth. Some of these lasers are integrated with modulators with a 3-dB bandwidth above 25 GHz, thus demonstrating coarse wavelength division multiplexing transmitter on silicon.

Biofunctionalization on alkylated silicon substrate surfaces via "click" chemistry.

PubMed

Qin, Guoting; Santos, Catherine; Zhang, Wen; Li, Yan; Kumar, Amit; Erasquin, Uriel J; Liu, Kai; Muradov, Pavel; Trautner, Barbara Wells; Cai, Chengzhi

2010-11-24

Biofunctionalization of silicon substrates is important to the development of silicon-based biosensors and devices. Compared to conventional organosiloxane films on silicon oxide intermediate layers, organic monolayers directly bound to the nonoxidized silicon substrates via Si-C bonds enhance the sensitivity of detection and the stability against hydrolytic cleavage. Such monolayers presenting a high density of terminal alkynyl groups for bioconjugation via copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC, a "click" reaction) were reported. However, yields of the CuAAC reactions on these monolayer platforms were low. Also, the nonspecific adsorption of proteins on the resultant surfaces remained a major obstacle for many potential biological applications. Herein, we report a new type of "clickable" monolayers grown by selective, photoactivated surface hydrosilylation of α,ω-alkenynes, where the alkynyl terminal is protected with a trimethylgermanyl (TMG) group, on hydrogen-terminated silicon substrates. The TMG groups on the film are readily removed in aqueous solutions in the presence of Cu(I). Significantly, the degermanylation and the subsequent CuAAC reaction with various azides could be combined into a single step in good yields. Thus, oligo(ethylene glycol) (OEG) with an azido tag was attached to the TMG-alkyne surfaces, leading to OEG-terminated surfaces that reduced the nonspecific adsorption of protein (fibrinogen) by >98%. The CuAAC reaction could be performed in microarray format to generate arrays of mannose and biotin with varied densities on the protein-resistant OEG background. We also demonstrated that the monolayer platform could be functionalized with mannose for highly specific capturing of living targets (Escherichia coli expressing fimbriae) onto the silicon substrates.

Using silicone gel sheet for the treatment of facial telangiectasias with sclerotherapy.

PubMed

Misirlioglu, Aykut; Gideroglu, Kaan; Akan, Mithat; Akoz, Tayfun

2004-03-01

Telangiectasias are superficial cutaneous vessels that are visible to human eye and are present as a dilated venule, capillary, or arteriole. They are a common cause of concern, especially when located in face. Sclerotherapy is among the treatment alternatives, but facial telangiectasias are less responsive than those located on the leg. To show the effectiveness of silicone gel sheet in improving the results obtained by sclerotherapy in facial telangiectasias. Between 1998 and 2003, 32 patients were treated with sclerotherapy and silicone gel sheet (group 1). Twenty-six patients were treated with sclerotherapy and cotton ball (group 2), and 30 patients were treated only sclerotherapy (group 3). Patients were evaluated for 12 weeks for the degree of improvement and side effects. All complications, side effects, and number of sessions were also recorded at each follow-up visit. The number of sessions is limited to six. After the final follow-up visit, the photographs taken of each treatment site at baseline and at final visit were reviewed in a double-blinded manner based on a 0 to 4 scale by two physicians. Fifty one of the 88 patients showed improvement totally. In the silicone sheet-sclerotherapy group, 22 of the 36 patients showed improvement. In the sclerotherapy-cotton ball group, 14 of the 26 patients showed improvement, and in the sclerotherapy-only group, 15 of the 30 patients showed improvement completely within the 12 weeks. The patients treated with sclerotherapy-silicone gel sheet (group 1) had more improvement than the other groups. Combining silicone gel sheeting to sclerotherapy increases the success rate in treating facial telangiectasias, especially facial subunits, which have bone support.

Mode-converting coupler for silicon-on-sapphire devices

NASA Astrophysics Data System (ADS)

Zlatanovic, S.; Offord, B. W.; Owen, M.; Shimabukuro, R.; Jacobs, E. W.

2015-02-01

Silicon-on-sapphire devices are attractive for the mid-infrared optical applications up to 5 microns due to the low loss of both silicon and sapphire in this wavelength band. Designing efficient couplers for silicon-on-sapphire devices presents a challenge due to a highly confined mode in silicon and large values of refractive index of both silicon and sapphire. Here, we present design, fabrication, and measurements of a mode-converting coupler for silicon-on-sapphire waveguides. We utilize a mode converter layout that consists of a large waveguide that is overlays a silicon inverse tapered waveguide. While this geometry was previously utilized for silicon-on-oxide devices, the novelty is in using materials that are compatible with the silicon-on-sapphire platform. In the current coupler the overlaying waveguide is made of silicon nitride. Silicon nitride is the material of choice because of the large index of refraction and low absorption from near-infrared to mid-infrared. The couplers were fabricated using a 0.25 micron silicon-on-sapphire process. The measured coupling loss from tapered lensed silica fibers to the silicon was 4.8dB/coupler. We will describe some challenges in fabrication process and discuss ways to overcome them.

Silicon-nanomembrane-based photonic crystal nanostructures for chip-integrated open sensor systems

NASA Astrophysics Data System (ADS)

Chakravarty, Swapnajit; Lai, Wei-Cheng; Zou, Yi; Lin, Cheyun; Wang, Xiaolong; Chen, Ray T.

2011-11-01

We experimentally demonstrate two devices on the photonic crystal platform for chip-integrated optical absorption spectroscopy and chip-integrated biomolecular microarray assays. Infrared optical absorption spectroscopy and biomolecular assays based on conjugate-specific binding principles represent two dominant sensing mechanisms for a wide spectrum of applications in environmental pollution sensing in air and water, chem-bio agents and explosives detection for national security, microbial contamination sensing in food and beverages to name a few. The easy scalability of photonic crystal devices to any wavelength ensures that the sensing principles hold across a wide electromagnetic spectrum. Silicon, the workhorse of the electronics industry, is an ideal platform for the above optical sensing applications.

Micropatterned arrays of porous silicon: toward sensory biointerfaces.

PubMed

Flavel, Benjamin S; Sweetman, Martin J; Shearer, Cameron J; Shapter, Joseph G; Voelcker, Nicolas H

2011-07-01

We describe the fabrication of arrays of porous silicon spots by means of photolithography where a positive photoresist serves as a mask during the anodization process. In particular, photoluminescent arrays and porous silicon spots suitable for further chemical modification and the attachment of human cells were created. The produced arrays of porous silicon were chemically modified by means of a thermal hydrosilylation reaction that facilitated immobilization of the fluorescent dye lissamine, and alternatively, the cell adhesion peptide arginine-glycine-aspartic acid-serine. The latter modification enabled the selective attachment of human lens epithelial cells on the peptide functionalized regions of the patterns. This type of surface patterning, using etched porous silicon arrays functionalized with biological recognition elements, presents a new format of interfacing porous silicon with mammalian cells. Porous silicon arrays with photoluminescent properties produced by this patterning strategy also have potential applications as platforms for in situ monitoring of cell behavior.

Neuromorphic photonic networks using silicon photonic weight banks.

PubMed

Tait, Alexander N; de Lima, Thomas Ferreira; Zhou, Ellen; Wu, Allie X; Nahmias, Mitchell A; Shastri, Bhavin J; Prucnal, Paul R

2017-08-07

Photonic systems for high-performance information processing have attracted renewed interest. Neuromorphic silicon photonics has the potential to integrate processing functions that vastly exceed the capabilities of electronics. We report first observations of a recurrent silicon photonic neural network, in which connections are configured by microring weight banks. A mathematical isomorphism between the silicon photonic circuit and a continuous neural network model is demonstrated through dynamical bifurcation analysis. Exploiting this isomorphism, a simulated 24-node silicon photonic neural network is programmed using "neural compiler" to solve a differential system emulation task. A 294-fold acceleration against a conventional benchmark is predicted. We also propose and derive power consumption analysis for modulator-class neurons that, as opposed to laser-class neurons, are compatible with silicon photonic platforms. At increased scale, Neuromorphic silicon photonics could access new regimes of ultrafast information processing for radio, control, and scientific computing.

Semiconductor meta-surface based perfect light absorber

NASA Astrophysics Data System (ADS)

Liu, Guiqiang; Nie, Yiyou; Fu, Guolan; Liu, Xiaoshan; Liu, Yi; Tang, Li; Liu, Zhengqi

2017-04-01

We numerically proposed and demonstrated a semiconductor meta-surface light absorber, which consists of a silicon patches array on a silicon thin-film and an opaque silver substrate. The Mie resonances of the silicon patches and the fundamental cavity mode of the ultra-thin silicon film couple strongly to the incident optical field, leading to a multi-band perfect absorption. The maximal absorption is above 99.5% and the absorption is polarization-independent. Moreover, the absorption behavior is scalable in the frequency region via tuning the structural parameters. These features hold the absorber platform with wide applications in optoelectronics such as hot-electron excitation and photo-detection.

Porous silicon advances in drug delivery and immunotherapy.

PubMed

Savage, David J; Liu, Xuewu; Curley, Steven A; Ferrari, Mauro; Serda, Rita E

2013-10-01

Biomedical applications of porous silicon include drug delivery, imaging, diagnostics and immunotherapy. This review summarizes new silicon particle fabrication techniques, dynamics of cellular transport, advances in the multistage vector approach to drug delivery, and the use of porous silicon as immune adjuvants. Recent findings support superior therapeutic efficacy of the multistage vector approach over single particle drug delivery systems in mouse models of ovarian and breast cancer. With respect to vaccine development, multivalent presentation of pathogen-associated molecular patterns on the particle surface creates powerful platforms for immunotherapy, with the porous matrix able to carry both antigens and immune modulators. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modification of porous silicon rugate filters through thiol-yne photochemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soeriyadi, Alexander H., E-mail: alexander.soeriyadi@unsw.edu.au; Zhu, Ying, E-mail: alexander.soeriyadi@unsw.edu.au; Gooding, J. Justin, E-mail: justin.gooding@unsw.edu.au

2014-02-24

Porous silicon (PSi) has a considerable potential as biosensor platform. In particular, the ability to modify the surface chemistry of porous silicon is of interest. Here we present a generic method to modify the surface of porous silicon through thiol-yne photochemistry initiated by a radical initiator. Firstly, a freshly etched porous silicon substrate is modified through thermal hydrosilylation with 1,8-nonadiyne to passivate the surface and introduce alkyne functionalities. The alkyne functional surface could then be further reacted with thiol species in the presence of a radical initiator and UV light. Functionalization of the PSi rugate filter is followed with opticalmore » reflectivity measurements as well as high resolution X-ray photoelectron spectroscopy (XPS)« less

Si/Ge elatform for lasers, amplifiers, and nonlinear optical devices based on the Raman Effect

NASA Astrophysics Data System (ADS)

Claps, Ricardo; Dimitropoulos, Dimitrios; Raghunathan, Varun; Fathpour, Sasan; Jalali, Bahram; Jusserand, Bernard

2007-02-01

The use of a silicon-germanium platform for the development of optically active devices will be discussed in this paper, from the perspective of Raman and Brillouin scattering phenomena. Silicon-Germanium is becoming a prevalent technology for the development of high speed CMOS transistors, with advances in several key parameters as high carrier mobility, low cost, and reduced manufacturing logistics. Traditionally, Si-Ge structures have been used in the optoelectronics arena as photodetectors, due to the enhanced absorption of Ge in the telecommunications band. Recent developments in Raman-based nonlinearities for devices based on a silicon-on-insulator platform have shed light on the possibility of using these effects in Si-Ge architectures. Lasing and amplification have been demonstrated using a SiGe alloy structure, and Brillouin/Raman activity from acoustic phonon modes in SiGe superlattices has been predicted. Moreover, new Raman-active branches and inhomogeneously broadened spectra result from optical phonon modes, offering new perspectives for optical device applications. The possibilities for an electrically-pumped Raman laser will be outlined, and the potential for design and development of silicon-based, Tera-Hertz wave emitters and/or receivers.

Large-scale quantum photonic circuits in silicon

NASA Astrophysics Data System (ADS)

Harris, Nicholas C.; Bunandar, Darius; Pant, Mihir; Steinbrecher, Greg R.; Mower, Jacob; Prabhu, Mihika; Baehr-Jones, Tom; Hochberg, Michael; Englund, Dirk

2016-08-01

Quantum information science offers inherently more powerful methods for communication, computation, and precision measurement that take advantage of quantum superposition and entanglement. In recent years, theoretical and experimental advances in quantum computing and simulation with photons have spurred great interest in developing large photonic entangled states that challenge today's classical computers. As experiments have increased in complexity, there has been an increasing need to transition bulk optics experiments to integrated photonics platforms to control more spatial modes with higher fidelity and phase stability. The silicon-on-insulator (SOI) nanophotonics platform offers new possibilities for quantum optics, including the integration of bright, nonclassical light sources, based on the large third-order nonlinearity (χ(3)) of silicon, alongside quantum state manipulation circuits with thousands of optical elements, all on a single phase-stable chip. How large do these photonic systems need to be? Recent theoretical work on Boson Sampling suggests that even the problem of sampling from e30 identical photons, having passed through an interferometer of hundreds of modes, becomes challenging for classical computers. While experiments of this size are still challenging, the SOI platform has the required component density to enable low-loss and programmable interferometers for manipulating hundreds of spatial modes. Here, we discuss the SOI nanophotonics platform for quantum photonic circuits with hundreds-to-thousands of optical elements and the associated challenges. We compare SOI to competing technologies in terms of requirements for quantum optical systems. We review recent results on large-scale quantum state evolution circuits and strategies for realizing high-fidelity heralded gates with imperfect, practical systems. Next, we review recent results on silicon photonics-based photon-pair sources and device architectures, and we discuss a path towards large-scale source integration. Finally, we review monolithic integration strategies for single-photon detectors and their essential role in on-chip feed forward operations.

Hybrid integration of III-V semiconductor lasers on silicon waveguides using optofluidic microbubble manipulation

PubMed Central

Jung, Youngho; Shim, Jaeho; Kwon, Kyungmook; You, Jong-Bum; Choi, Kyunghan; Yu, Kyoungsik

2016-01-01

Optofluidic manipulation mechanisms have been successfully applied to micro/nano-scale assembly and handling applications in biophysics, electronics, and photonics. Here, we extend the laser-based optofluidic microbubble manipulation technique to achieve hybrid integration of compound semiconductor microdisk lasers on the silicon photonic circuit platform. The microscale compound semiconductor block trapped on the microbubble surface can be precisely assembled on a desired position using photothermocapillary convective flows induced by focused laser beam illumination. Strong light absorption within the micro-scale compound semiconductor object allows real-time and on-demand microbubble generation. After the assembly process, we verify that electromagnetic radiation from the optically-pumped InGaAsP microdisk laser can be efficiently coupled to the single-mode silicon waveguide through vertical evanescent coupling. Our simple and accurate microbubble-based manipulation technique may provide a new pathway for realizing high precision fluidic assembly schemes for heterogeneously integrated photonic/electronic platforms as well as microelectromechanical systems. PMID:27431769

A monolithically integrated polarization entangled photon pair source on a silicon chip

PubMed Central

Matsuda, Nobuyuki; Le Jeannic, Hanna; Fukuda, Hiroshi; Tsuchizawa, Tai; Munro, William John; Shimizu, Kaoru; Yamada, Koji; Tokura, Yasuhiro; Takesue, Hiroki

2012-01-01

Integrated photonic circuits are one of the most promising platforms for large-scale photonic quantum information systems due to their small physical size and stable interferometers with near-perfect lateral-mode overlaps. Since many quantum information protocols are based on qubits defined by the polarization of photons, we must develop integrated building blocks to generate, manipulate, and measure the polarization-encoded quantum state on a chip. The generation unit is particularly important. Here we show the first integrated polarization-entangled photon pair source on a chip. We have implemented the source as a simple and stable silicon-on-insulator photonic circuit that generates an entangled state with 91 ± 2% fidelity. The source is equipped with versatile interfaces for silica-on-silicon or other types of waveguide platforms that accommodate the polarization manipulation and projection devices as well as pump light sources. Therefore, we are ready for the full-scale implementation of photonic quantum information systems on a chip. PMID:23150781

Exploiting metamaterials, plasmonics and nanoantennas concepts in silicon photonics

NASA Astrophysics Data System (ADS)

Rodríguez-Fortuño, Francisco J.; Espinosa-Soria, Alba; Martínez, Alejandro

2016-12-01

The interaction of light with subwavelength metallic nano-structures is at the heart of different current scientific hot topics, namely plasmonics, metamaterials and nanoantennas. Research in these disciplines during the last decade has given rise to new, powerful concepts providing an unprecedented degree of control over light manipulation at the nanoscale. However, only recently have these concepts been used to increase the capabilities of light processing in current photonic integrated circuits (PICs), which traditionally rely only on dielectric materials with element sizes larger than the light wavelength. Amongst the different PIC platforms, silicon photonics is expected to become mainstream, since manufacturing using well-established CMOS processes enables the mass production of low-cost PICs. In this review we discuss the benefits of introducing recent concepts arisen from the fields of metamaterials, plasmonics and nanoantennas into a silicon photonics integrated platform. We review existing works in this direction and discuss how this hybrid approach can lead to the improvement of current PICs enabling novel and disruptive applications in photonics.

Mid-infrared materials and devices on a Si platform for optical sensing

PubMed Central

Singh, Vivek; Lin, Pao Tai; Patel, Neil; Lin, Hongtao; Li, Lan; Zou, Yi; Deng, Fei; Ni, Chaoying; Hu, Juejun; Giammarco, James; Soliani, Anna Paola; Zdyrko, Bogdan; Luzinov, Igor; Novak, Spencer; Novak, Jackie; Wachtel, Peter; Danto, Sylvain; Musgraves, J David; Richardson, Kathleen; Kimerling, Lionel C; Agarwal, Anuradha M

2014-01-01

In this article, we review our recent work on mid-infrared (mid-IR) photonic materials and devices fabricated on silicon for on-chip sensing applications. Pedestal waveguides based on silicon are demonstrated as broadband mid-IR sensors. Our low-loss mid-IR directional couplers demonstrated in SiNx waveguides are useful in differential sensing applications. Photonic crystal cavities and microdisk resonators based on chalcogenide glasses for high sensitivity are also demonstrated as effective mid-IR sensors. Polymer-based functionalization layers, to enhance the sensitivity and selectivity of our sensor devices, are also presented. We discuss the design of mid-IR chalcogenide waveguides integrated with polycrystalline PbTe detectors on a monolithic silicon platform for optical sensing, wherein the use of a low-index spacer layer enables the evanescent coupling of mid-IR light from the waveguides to the detector. Finally, we show the successful fabrication processing of our first prototype mid-IR waveguide-integrated detectors. PMID:27877641

Integrated Microfluidic Gas Sensors for Water Monitoring

NASA Technical Reports Server (NTRS)

Zhu, L.; Sniadecki, N.; DeVoe, D. L.; Beamesderfer, M.; Semancik, S.; DeVoe, D. L.

2003-01-01

A silicon-based microhotplate tin oxide (SnO2) gas sensor integrated into a polymer-based microfluidic system for monitoring of contaminants in water systems is presented. This device is designed to sample a water source, control the sample vapor pressure within a microchannel using integrated resistive heaters, and direct the vapor past the integrated gas sensor for analysis. The sensor platform takes advantage of novel technology allowing direct integration of discrete silicon chips into a larger polymer microfluidic substrate, including seamless fluidic and electrical interconnects between the substrate and silicon chip.

Octave-spanning supercontinuum generation in a silicon-rich nitride waveguide.

PubMed

Liu, Xing; Pu, Minhao; Zhou, Binbin; Krückel, Clemens J; Fülöp, Attila; Torres-Company, Victor; Bache, Morten

2016-06-15

We experimentally show octave-spanning supercontinuum generation in a nonstoichiometric silicon-rich nitride waveguide when pumped by femtosecond pulses from an erbium fiber laser. The pulse energy and bandwidth are comparable to results achieved in stoichiometric silicon nitride waveguides, but our material platform is simpler to manufacture. We also observe wave-breaking supercontinuum generation by using orthogonal pumping in the same waveguide. Additional analysis reveals that the waveguide height is a powerful tuning parameter for generating mid-infrared dispersive waves while keeping the pump in the telecom band.

50 Gb/s hybrid silicon traveling-wave electroabsorption modulator.

PubMed

Tang, Yongbo; Chen, Hui-Wen; Jain, Siddharth; Peters, Jonathan D; Westergren, Urban; Bowers, John E

2011-03-28

We have demonstrated a traveling-wave electroabsorption modulator based on the hybrid silicon platform. For a device with a 100 μm active segment, the small-signal electro/optical response renders a 3 dB bandwidth of around 42 GHz and its modulation efficiency reaches 23 GHz/V. A dynamic extinction ratio of 9.8 dB with a driving voltage swing of only 2 V was demonstrated at a transmission rate of 50 Gb/s. This represents a significant improvement for modulators compatible with integration of silicon-based photonic integrated circuits.

Progress on Platforms, Sensors and Applications with Unmanned Aerial Vehicles in soil science and geomorphology

NASA Astrophysics Data System (ADS)

Anders, Niels; Suomalainen, Juha; Seeger, Manuel; Keesstra, Saskia; Bartholomeus, Harm; Paron, Paolo

2014-05-01

The recent increase of performance and endurance of electronically controlled flying platforms, such as multi-copters and fixed-wing airplanes, and decreasing size and weight of different sensors and batteries leads to increasing popularity of Unmanned Aerial Systems (UAS) for scientific purposes. Modern workflows that implement UAS include guided flight plan generation, 3D GPS navigation for fully automated piloting, and automated processing with new techniques such as "Structure from Motion" photogrammetry. UAS are often equipped with normal RGB cameras, multi- and hyperspectral sensors, radar, or other sensors, and provide a cheap and flexible solution for creating multi-temporal data sets. UAS revolutionized multi-temporal research allowing new applications related to change analysis and process monitoring. The EGU General Assembly 2014 is hosting a session on platforms, sensors and applications with UAS in soil science and geomorphology. This presentation briefly summarizes the outcome of this session, addressing the current state and future challenges of small-platform data acquisition in soil science and geomorphology.

Polyelectrolyte multilayer-assisted fabrication of non-periodic silicon nanocolumn substrates for cellular interface applications

NASA Astrophysics Data System (ADS)

Lee, Seyeong; Kim, Dongyoon; Kim, Seong-Min; Kim, Jeong-Ah; Kim, Taesoo; Kim, Dong-Yu; Yoon, Myung-Han

2015-08-01

Recent advances in nanostructure-based biotechnology have resulted in a growing demand for vertical nanostructure substrates with elaborate control over the nanoscale geometry and a high-throughput preparation. In this work, we report the fabrication of non-periodic vertical silicon nanocolumn substrates via polyelectrolyte multilayer-enabled randomized nanosphere lithography. Owing to layer-by-layer deposited polyelectrolyte adhesives, uniformly-separated polystyrene nanospheres were securely attached on large silicon substrates and utilized as masks for the subsequent metal-assisted silicon etching in solution. Consequently, non-periodic vertical silicon nanocolumn arrays were successfully fabricated on a wafer scale, while each nanocolumn geometric factor, such as the diameter, height, density, and spatial patterning, could be fully controlled in an independent manner. Finally, we demonstrate that our vertical silicon nanocolumn substrates support viable cell culture with minimal cell penetration and unhindered cell motility due to the blunt nanocolumn morphology. These results suggest that vertical silicon nanocolumn substrates may serve as a useful cellular interface platform for performing a statistically meaningful number of cellular experiments in the fields of biomolecular delivery, stem cell research, etc.Recent advances in nanostructure-based biotechnology have resulted in a growing demand for vertical nanostructure substrates with elaborate control over the nanoscale geometry and a high-throughput preparation. In this work, we report the fabrication of non-periodic vertical silicon nanocolumn substrates via polyelectrolyte multilayer-enabled randomized nanosphere lithography. Owing to layer-by-layer deposited polyelectrolyte adhesives, uniformly-separated polystyrene nanospheres were securely attached on large silicon substrates and utilized as masks for the subsequent metal-assisted silicon etching in solution. Consequently, non-periodic vertical silicon nanocolumn arrays were successfully fabricated on a wafer scale, while each nanocolumn geometric factor, such as the diameter, height, density, and spatial patterning, could be fully controlled in an independent manner. Finally, we demonstrate that our vertical silicon nanocolumn substrates support viable cell culture with minimal cell penetration and unhindered cell motility due to the blunt nanocolumn morphology. These results suggest that vertical silicon nanocolumn substrates may serve as a useful cellular interface platform for performing a statistically meaningful number of cellular experiments in the fields of biomolecular delivery, stem cell research, etc. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr02384j

Trimming of silicon ring resonator by electron beam induced compaction and strain.

PubMed

Schrauwen, J; Van Thourhout, D; Baets, R

2008-03-17

Silicon is becoming the preferable platform for future integrated components, mostly due to the mature and reliable fabrication capabilities of electronics industry. Nevertheless, even the most advanced fabrication technologies suffer from non-uniformity on wafer scale and on chip scale, causing variations in the critical dimensions of fabricated components. This is an important issue since photonic circuits, and especially cavities such as ring resonators, are extremely sensitive to these variations. In this paper we present a way to circumvent these problems by trimming using electron beam induced compaction of oxide in silicon on insulator. Volume compaction of the oxide cladding causes both changes in the refractive index and creates strain in the silicon lattice. We demonstrate a resonance wavelength red shift 4.91 nm in a silicon ring resonator.

Highly linear ring modulator from hybrid silicon and lithium niobate.

PubMed

Chen, Li; Chen, Jiahong; Nagy, Jonathan; Reano, Ronald M

2015-05-18

We present a highly linear ring modulator from the bonding of ion-sliced x-cut lithium niobate onto a silicon ring resonator. The third order intermodulation distortion spurious free dynamic range is measured to be 98.1 dB Hz(2/3) and 87.6 dB Hz(2/3) at 1 GHz and 10 GHz, respectively. The linearity is comparable to a reference lithium niobate Mach-Zehnder interferometer modulator operating at quadrature and over an order of magnitude greater than silicon ring modulators based on plasma dispersion effect. Compact modulators for analog optical links that exploit the second order susceptibility of lithium niobate on the silicon platform are envisioned.

Reconfigurable Cellular Photonic Crystal Arrays (RCPA)

DTIC Science & Technology

2013-03-01

signal processing based on reconfigurable integrated optics devices. This technology has the potential to revolutionize the design circle of optical...Accomplishments III.A. Design and fabrication of an accumulation-mode modulator Figure 1(a) shows the schematic of a compact resonator on the double-Si... integration of silicon nitride on silicon-on-insulator platform to enhance the arsenal of photonic circuit designers . The coherent integration of

Thermo-optic characteristics and switching power limit of slow-light photonic crystal structures on a silicon-on-insulator platform.

PubMed

Chahal, Manjit; Celler, George K; Jaluria, Yogesh; Jiang, Wei

2012-02-13

Employing a semi-analytic approach, we study the influence of key structural and optical parameters on the thermo-optic characteristics of photonic crystal waveguide (PCW) structures on a silicon-on-insulator (SOI) platform. The power consumption and spatial temperature profile of such structures are given as explicit functions of various structural, thermal and optical parameters, offering physical insight not available in finite-element simulations. Agreement with finite-element simulations and experiments is demonstrated. Thermal enhancement of the air-bridge structure is analyzed. The practical limit of thermo-optic switching power in slow light PCWs is discussed, and the scaling with key parameters is analyzed. Optical switching with sub-milliwatt power is shown viable.

Summary of the First Network-Centric Sensing Community Workshop, ’Netted Sensors: A Government, Industry and Academia Dialogue’

DTIC Science & Technology

2006-04-01

and Scalability, (2) Sensors and Platforms, (3) Distributed Computing and Processing , (4) Information Management, (5) Fusion and Resource Management...use of the deployed system. 3.3 Distributed Computing and Processing Session The Distributed Computing and Processing Session consisted of three

Home dialysis and the Internet: designing an e-learning platform via brainstorming sessions.

PubMed

Piccoli, Giorgina Barbara; Ferraresi, Martina; Murciano, Antonio; Pereno, Amina; Consiglio, Valentina; Scognamiglio, Stefania; Deagostini, Maria Chiara; Randone, Olga; Digiorgio, Gerardo; Calderale, Mario Pasquale

2012-01-01

The resurgence of home hemodialysis (HHD) underlines the importance of educational programs. Brainstorming is a powerful tool for innovation, widely employed in industry but seldom used in medicine. The aim of this study was to define an e-learning Web platform for HHD patients via a brainstorming approach. Four brainstorming sessions were held 2-6 weeks apart. Twelve people were involved: 2 dialysis physicians, 2 nurses, 2 HHD patients, 2 caregivers, a filmmaker, 2 computer experts (1 with a psychology degree) and a senior engineer. Each session was summarized as the starting point for the following one. The topics discussed were the platform structure and its logo. For the platform, the following requirements were defined: teaching should be extensive and tailored to different levels of knowledge; all available teaching tools (tutorials, demonstrations, recorded and written materials) should be used; films enhance emotional participation and can be used to reduce fears; the contents should include general information on chronic kidney disease, details of all types of renal replacement therapy (RRT) (how and why), dialysis accidents, blood and imaging tests, laws and reimbursements, direct experiences and history of RRT. Remote monitoring and visual interactions are important for reassurance about HHD and should be provided. The requirements for the logo were that it be innovative, related to daily life, representative of a holistic approach and convey happiness. The logo "Hom-e-hem" was created, playing on the assonance between the religious term Om and the word home, with the e of electronic linking it with hem, short for hemodialysis. Brainstorming sessions can be used to design patient-tailored educational interventions. The key message, "self-care is a bridge from illness back to life," may apply to a wider context.

Software-defined networking control plane for seamless integration of multiple silicon photonic switches in Datacom networks.

PubMed

Shen, Yiwen; Hattink, Maarten H N; Samadi, Payman; Cheng, Qixiang; Hu, Ziyiz; Gazman, Alexander; Bergman, Keren

2018-04-16

Silicon photonics based switches offer an effective option for the delivery of dynamic bandwidth for future large-scale Datacom systems while maintaining scalable energy efficiency. The integration of a silicon photonics-based optical switching fabric within electronic Datacom architectures requires novel network topologies and arbitration strategies to effectively manage the active elements in the network. We present a scalable software-defined networking control plane to integrate silicon photonic based switches with conventional Ethernet or InfiniBand networks. Our software-defined control plane manages both electronic packet switches and multiple silicon photonic switches for simultaneous packet and circuit switching. We built an experimental Dragonfly network testbed with 16 electronic packet switches and 2 silicon photonic switches to evaluate our control plane. Observed latencies occupied by each step of the switching procedure demonstrate a total of 344 µs control plane latency for data-center and high performance computing platforms.

Magneto-optical non-reciprocal devices in silicon photonics

PubMed Central

Shoji, Yuya; Mizumoto, Tetsuya

2014-01-01

Silicon waveguide optical non-reciprocal devices based on the magneto-optical effect are reviewed. The non-reciprocal phase shift caused by the first-order magneto-optical effect is effective in realizing optical non-reciprocal devices in silicon waveguide platforms. In a silicon-on-insulator waveguide, the low refractive index of the buried oxide layer enhances the magneto-optical phase shift, which reduces the device footprints. A surface activated direct bonding technique was developed to integrate a magneto-optical garnet crystal on the silicon waveguides. A silicon waveguide optical isolator based on the magneto-optical phase shift was demonstrated with an optical isolation of 30 dB and insertion loss of 13 dB at a wavelength of 1548 nm. Furthermore, a four port optical circulator was demonstrated with maximum isolations of 15.3 and 9.3 dB in cross and bar ports, respectively, at a wavelength of 1531 nm. PMID:27877640

Climate for Entrepreneurship and Innovation in the United States. Hearings before the Joint Economic Committee, Congress of the United States, Ninety-Eighth Congress, Second Session. Part 2. August 27 and 28, 1984--A Silicon Valley Perspective. August 30 and 31, 1984--A Route 128 Perspective.

ERIC Educational Resources Information Center

Joint Economic Committee, Washington, DC.

This Congressional report deals with the views of persons residing and working in the Silicon Valley in California and near Route 128 around Boston on strategies for encouraging entrepreneurship. Included among those persons providing testimony concerning the perspectives of individuals and groups from these two regions were representatives of the…

Superior Robust Ultrathin Single-Crystalline Silicon Carbide Membrane as a Versatile Platform for Biological Applications.

PubMed

Nguyen, Tuan-Khoa; Phan, Hoang-Phuong; Kamble, Harshad; Vadivelu, Raja; Dinh, Toan; Iacopi, Alan; Walker, Glenn; Hold, Leonie; Nguyen, Nam-Trung; Dao, Dzung Viet

2017-12-06

Micromachined membranes are promising platforms for cell culture thanks to their miniaturization and integration capabilities. Possessing chemical inertness, biocompatibility, and integration, silicon carbide (SiC) membranes have attracted great interest toward biological applications. In this paper, we present the batch fabrication, mechanical characterizations, and cell culture demonstration of robust ultrathin epitaxial deposited SiC membranes. The as-fabricated ultrathin SiC membranes, with an ultrahigh aspect ratio (length/thickness) of up to 20 000, possess high a fracture strength up to 2.95 GPa and deformation up to 50 μm. A high optical transmittance of above 80% at visible wavelengths was obtained for 50 nm membranes. The as-fabricated membranes were experimentally demonstrated as an excellent substrate platform for bio-MEMS/NEMS cell culture with the cell viability rate of more than 92% after 72 h. The ultrathin SiC membrane is promising for in vitro observations/imaging of bio-objects with an extremely short optical access.

Silicon photonics for high-performance interconnection networks

NASA Astrophysics Data System (ADS)

Biberman, Aleksandr

2011-12-01

We assert in the course of this work that silicon photonics has the potential to be a key disruptive technology in computing and communication industries. The enduring pursuit of performance gains in computing, combined with stringent power constraints, has fostered the ever-growing computational parallelism associated with chip multiprocessors, memory systems, high-performance computing systems, and data centers. Sustaining these parallelism growths introduces unique challenges for on- and off-chip communications, shifting the focus toward novel and fundamentally different communication approaches. This work showcases that chip-scale photonic interconnection networks, enabled by high-performance silicon photonic devices, enable unprecedented bandwidth scalability with reduced power consumption. We demonstrate that the silicon photonic platforms have already produced all the high-performance photonic devices required to realize these types of networks. Through extensive empirical characterization in much of this work, we demonstrate such feasibility of waveguides, modulators, switches, and photodetectors. We also demonstrate systems that simultaneously combine many functionalities to achieve more complex building blocks. Furthermore, we leverage the unique properties of available silicon photonic materials to create novel silicon photonic devices, subsystems, network topologies, and architectures to enable unprecedented performance of these photonic interconnection networks and computing systems. We show that the advantages of photonic interconnection networks extend far beyond the chip, offering advanced communication environments for memory systems, high-performance computing systems, and data centers. Furthermore, we explore the immense potential of all-optical functionalities implemented using parametric processing in the silicon platform, demonstrating unique methods that have the ability to revolutionize computation and communication. Silicon photonics enables new sets of opportunities that we can leverage for performance gains, as well as new sets of challenges that we must solve. Leveraging its inherent compatibility with standard fabrication techniques of the semiconductor industry, combined with its capability of dense integration with advanced microelectronics, silicon photonics also offers a clear path toward commercialization through low-cost mass-volume production. Combining empirical validations of feasibility, demonstrations of massive performance gains in large-scale systems, and the potential for commercial penetration of silicon photonics, the impact of this work will become evident in the many decades that follow.

Thermal and Kerr nonlinear properties of plasma-deposited silicon nitride/ silicon dioxide waveguides.

PubMed

Ikeda, Kazuhiro; Saperstein, Robert E; Alic, Nikola; Fainman, Yeshaiahu

2008-08-18

We introduce and present experimental evaluations of loss and nonlinear optical response in a waveguide and an optical resonator, both implemented with a silicon nitride/ silicon dioxide material platform prepared by plasma-enhanced chemical vapor deposition with dual frequency reactors that significantly reduce the stress and the consequent loss of the devices. We measure a relatively small loss of approximately 4dB/cm in the waveguides. The fabricated ring resonators in add-drop and all-pass arrangements demonstrate quality factors of Q=12,900 and 35,600. The resonators are used to measure both the thermal and ultrafast Kerr nonlinearities. The measured thermal nonlinearity is larger than expected, which is attributed to slower heat dissipation in the plasma-deposited silicon dioxide film. The n2 for silicon nitride that is unknown in the literature is measured, for the first time, as 2.4 x 10(-15)cm(2)/W, which is 10 times larger than that for silicon dioxide.

Silicon-on-insulator polarization splitting and rotating device for polarization diversity circuits.

PubMed

Liu, Liu; Ding, Yunhong; Yvind, Kresten; Hvam, Jørn M

2011-06-20

A compact and efficient polarization splitting and rotating device built on the silicon-on-insulator platform is introduced, which can be readily used for the interface section of a polarization diversity circuit. The device is compact, with a total length of a few tens of microns. It is also simple, consisting of only two parallel silicon-on-insulator wire waveguides with different widths, and thus requiring no additional and nonstandard fabrication steps. A total insertion loss of -0.6 dB and an extinction ratio of 12 dB have been obtained experimentally in the whole C-band.

Integration of carbon nanotubes in slot waveguides (Conference Presentation)

NASA Astrophysics Data System (ADS)

Durán-Valdeiglesias, Elena; Zhang, Weiwei; Hoang, Thi Hong Cam; Alonso-Ramos, Carlos; Serna, Samuel; Le Roux, Xavier; Cassan, Eric; Balestrieri, Matteo; Keita, Al-Saleh; Sarti, Francesco; Biccari, Francesco; Torrini, Ughetta; Vinattieri, Anna; Yang, Hongliu; Bezugly, Viktor; Cuniberti, Gianaurelio; Filoramo, Arianna; Gurioli, Massimo; Vivien, Laurent

2016-05-01

Demanding applications such as video streaming, social networking, or web search relay on a large network of data centres, interconnected through optical links. The ever-growing data rates and power consumption inside these data centres are pushing copper links close to their fundamental limits. Optical interconnects are being extensively studied with the purpose of solving these limitations. Among the different possible technology platforms, silicon photonics, due to its compatibility with the CMOS platform, has become one of the preferred solutions for the development of the future generation photonic interconnects. However, the on-chip integration of all photonic and optoelectronic building blocks (sources, modulators and detectors…) is very complex and is not cost-effective due to the various materials involved (Ge for detection, doped Si for modulators and III-V for lasing). Carbon nanotubes (CNTs) are nanomaterials of great interest in photonics thanks to their fundamental optical properties, including near-IR room-temperature foto- and electro- luminescence, Stark effect, Kerr effect and absorption. In consequence, CNTs have the ability to emit, modulate and detect light in the telecommunications wavelength range. Furthermore, they are being extensively developed for new nano-electronics applications. In this work, we propose to use CNTs as active material integrated into silicon photonics for the development of all optoelectronic devices. Here, we report on the development of new integration schemes to couple the light emission from CNTs into optical resonators implemented on the silicon-on-insulator and silicon-nitride-on-insulator platforms. A theoretical and experimental analysis of the light interaction of CNTs with micro-ring resonators based on strip and slot waveguides and slot photonic crystal heterostructure cavities were carried out.

A Low-wear Planar-contact Silicon Raceway for Microball Bearing Applications

DTIC Science & Technology

2009-04-01

of friction between stainless steel microballs and silicon grooves (18–20). Both linear and rotary micromotors for sensor platforms were developed...mechanism, like a micromotor , will enable devices to reach higher speeds. Previously, the radial surface wear track depth was >15 m for a device...can lead to significant whirl and axial misalignment, which is critical for micromotor and micropump applications. Small changes in the alignment

A mock heart engineered with helical aramid fibers for in vitro cardiovascular device testing.

PubMed

Jansen-Park, So-Hyun; Hsu, Po-Lin; Müller, Indra; Steinseifer, Ulrich; Abel, Dirk; Autschbach, Rüdiger; Rossaint, Rolf; Schmitz-Rode, Thomas

2017-04-01

Mock heart circulation loops (MHCLs) serve as in-vitro platforms to investigate the physiological interaction between circulatory systems and cardiovascular devices. A mock heart (MH) engineered with silicone walls and helical aramid fibers, to mimic the complex contraction of a natural heart, has been developed to advance the MHCL previously developed in our group. A mock aorta with an anatomical shape enables the evaluation of a cannulation method for ventricular assist devices (VADs) and investigation of the usage of clinical measurement systems like pressure-volume catheters. Ventricle and aorta molds were produced based on MRI data and cast with silicone. Aramid fibers were layered in the silicone ventricle to reproduce ventricle torsion. A rotating hollow shaft was connected to the apex enabling the rotation of the MH and the connection of a VAD. Silicone wall thickness, aramid fiber angle and fiber pitch were varied to generate different MH models. All MH models were placed in a tank filled with variable amounts of water and air simulating the compliance. In this work, physiological ventricular torsion angles (15°-26°) and physiological pressure-volume loops were achieved. This MHCL can serve as a comprehensive testing platform for cardiovascular devices, such as artificial heart valves and cannulation of VADs.

The model for Fundamentals of Endovascular Surgery (FEVS) successfully defines the competent endovascular surgeon.

PubMed

Duran, Cassidy; Estrada, Sean; O'Malley, Marcia; Sheahan, Malachi G; Shames, Murray L; Lee, Jason T; Bismuth, Jean

2015-12-01

Fundamental skills testing is now required for certification in general surgery. No model for assessing fundamental endovascular skills exists. Our objective was to develop a model that tests the fundamental endovascular skills and differentiates competent from noncompetent performance. The Fundamentals of Endovascular Surgery model was developed in silicon and virtual-reality versions. Twenty individuals (with a range of experience) performed four tasks on each model in three separate sessions. Tasks on the silicon model were performed under fluoroscopic guidance, and electromagnetic tracking captured motion metrics for catheter tip position. Image processing captured tool tip position and motion on the virtual model. Performance was evaluated using a global rating scale, blinded video assessment of error metrics, and catheter tip movement and position. Motion analysis was based on derivations of speed and position that define proficiency of movement (spectral arc length, duration of submovement, and number of submovements). Performance was significantly different between competent and noncompetent interventionalists for the three performance measures of motion metrics, error metrics, and global rating scale. The mean error metric score was 6.83 for noncompetent individuals and 2.51 for the competent group (P < .0001). Median global rating scores were 2.25 for the noncompetent group and 4.75 for the competent users (P < .0001). The Fundamentals of Endovascular Surgery model successfully differentiates competent and noncompetent performance of fundamental endovascular skills based on a series of objective performance measures. This model could serve as a platform for skills testing for all trainees. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Review of silicon photonics: history and recent advances

NASA Astrophysics Data System (ADS)

Ye, Winnie N.; Xiong, Yule

2013-09-01

Silicon photonics has attracted tremendous attention and research effort as a promising technology in optoelectronic integration for computing, communications, sensing, and solar harvesting. Mainly due to the combination of its excellent material properties and the complementary metal-oxide semiconductor (CMOS) fabrication processing technology, silicon has becoming the material choice for photonic and optoelectronic circuits with low cost, ultra-compact device footprint, and high-density integration. This review paper provides an overview on silicon photonics, by highlighting the early work from the mid-1980s on the fundamental building blocks such as silicon platforms and waveguides, and the main milestones that have been achieved so far in the field. A summary of reported work on functional elements in both passive and active devices, as well as the applications of the technology in interconnect, sensing, and solar cells, is identified.

Near-infrared sub-bandgap all-silicon photodetectors: state of the art and perspectives.

PubMed

Casalino, Maurizio; Coppola, Giuseppe; Iodice, Mario; Rendina, Ivo; Sirleto, Luigi

2010-01-01

Due to recent breakthroughs, silicon photonics is now the most active discipline within the field of integrated optics and, at the same time, a present reality with commercial products available on the market. Silicon photodiodes are excellent detectors at visible wavelengths, but the development of high-performance photodetectors on silicon CMOS platforms at wavelengths of interest for telecommunications has remained an imperative but unaccomplished task so far. In recent years, however, a number of near-infrared all-silicon photodetectors have been proposed and demonstrated for optical interconnect and power-monitoring applications. In this paper, a review of the state of the art is presented. Devices based on mid-bandgap absorption, surface-state absorption, internal photoemission absorption and two-photon absorption are reported, their working principles elucidated and their performance discussed and compared.

Near-Infrared Sub-Bandgap All-Silicon Photodetectors: State of the Art and Perspectives

PubMed Central

Casalino, Maurizio; Coppola, Giuseppe; Iodice, Mario; Rendina, Ivo; Sirleto, Luigi

2010-01-01

Due to recent breakthroughs, silicon photonics is now the most active discipline within the field of integrated optics and, at the same time, a present reality with commercial products available on the market. Silicon photodiodes are excellent detectors at visible wavelengths, but the development of high-performance photodetectors on silicon CMOS platforms at wavelengths of interest for telecommunications has remained an imperative but unaccomplished task so far. In recent years, however, a number of near-infrared all-silicon photodetectors have been proposed and demonstrated for optical interconnect and power-monitoring applications. In this paper, a review of the state of the art is presented. Devices based on mid-bandgap absorption, surface-state absorption, internal photoemission absorption and two-photon absorption are reported, their working principles elucidated and their performance discussed and compared. PMID:22163487

Mid-infrared integrated photonics on silicon: a perspective

NASA Astrophysics Data System (ADS)

Lin, Hongtao; Luo, Zhengqian; Gu, Tian; Kimerling, Lionel C.; Wada, Kazumi; Agarwal, Anu; Hu, Juejun

2017-12-01

The emergence of silicon photonics over the past two decades has established silicon as a preferred substrate platform for photonic integration. While most silicon-based photonic components have so far been realized in the near-infrared (near-IR) telecommunication bands, the mid-infrared (mid-IR, 2-20-μm wavelength) band presents a significant growth opportunity for integrated photonics. In this review, we offer our perspective on the burgeoning field of mid-IR integrated photonics on silicon. A comprehensive survey on the state-of-the-art of key photonic devices such as waveguides, light sources, modulators, and detectors is presented. Furthermore, on-chip spectroscopic chemical sensing is quantitatively analyzed as an example of mid-IR photonic system integration based on these basic building blocks, and the constituent component choices are discussed and contrasted in the context of system performance and integration technologies.

Tapered polysilicon core fibers for nonlinear photonics.

PubMed

Suhailin, Fariza H; Shen, Li; Healy, Noel; Xiao, Limin; Jones, Maxwell; Hawkins, Thomas; Ballato, John; Gibson, Ursula J; Peacock, Anna C

2016-04-01

We propose and demonstrate a novel approach to obtaining small-core polysilicon waveguides from the silicon fiber platform. The fibers were fabricated via a conventional drawing tower method and, subsequently, tapered down to achieve silicon core diameters of ∼1  μm, the smallest optical cores for this class of fiber to date. Characterization of the material properties have shown that the taper process helps to improve the local crystallinity of the silicon core, resulting in a significant reduction in the material loss. By exploiting the combination of small cores and low losses, these tapered fibers have enabled the first observation of nonlinear transmission within a polycrystalline silicon waveguide of any type. As the fiber drawing method is highly scalable, it opens a route for the development of low-cost and flexible nonlinear silicon photonic systems.

The AT Odyssey Continues. Proceedings of the RESNA 2001 Annual Conference (Reno, Nevada, June 22-26, 2001). Volume 21.

ERIC Educational Resources Information Center

Simpson, Richard, Ed.

These proceedings of the annual RESNA (Association for the Advancement of Rehabilitation Technology) conference include more than 200 presentations on all facets of assistive technology, including concurrent sessions, scientific platform sessions, interactive poster presentations, computer demonstrations, and the research symposia. The scientific…

Exploring SETAC's roles in the global dialogue on sustainability--an opening debate.

PubMed

McCormick, Ron; Kapustka, Larry; Stahl, Cynthia; Fava, Jim; Lavoie, Emma; Robertson, Cory; Sanderson, Hans; Scott, Heidi; Seager, Tom; Vigon, Bruce

2013-01-01

A combination platform-debate session was held at the Society of Environmental Toxicology and Chemistry (SETAC) North America annual meeting in Boston (November 2011). The session was organized by members of the Advisory Group on Sustainability, newly formed and approved as a global entity by the SETAC World Council just prior to the meeting. The platform portion of the session provided a historical backdrop for the debate that was designed to explore SETAC's role in the sustainability dialogue. The debate portion presented arguments for and against the proposition that "Science is the primary contribution of SETAC to the global dialogue on sustainability." Although the debate was not designed to achieve a definitive sustainability policy for SETAC, the audience clearly rejected the proposition, indicating a desire from the SETAC membership for an expanded role in global sustainability forums. This commentary details the key elements of the session, identifies the contribution the Advisory Group will have at the World Congress in Berlin (May 2012), and invites interested persons to become active in the Advisory Group. Copyright © 2012 SETAC.

Low-power silicon-organic hybrid (SOH) modulators for advanced modulation formats.

PubMed

Lauermann, M; Palmer, R; Koeber, S; Schindler, P C; Korn, D; Wahlbrink, T; Bolten, J; Waldow, M; Elder, D L; Dalton, L R; Leuthold, J; Freude, W; Koos, C

2014-12-01

We demonstrate silicon-organic hybrid (SOH) electro-optic modulators that enable quadrature phase-shift keying (QPSK) and 16-state quadrature amplitude modulation (16QAM) with high signal quality and record-low energy consumption. SOH integration combines highly efficient electro-optic organic materials with conventional silicon-on-insulator (SOI) slot waveguides, and allows to overcome the intrinsic limitations of silicon as an optical integration platform. We demonstrate QPSK and 16QAM signaling at symbol rates of 28 GBd with peak-to-peak drive voltages of 0.6 V(pp). For the 16QAM experiment at 112 Gbit/s, we measure a bit-error ratio of 5.1 × 10⁻⁵ and a record-low energy consumption of only 19 fJ/bit.

Sensitive Detection of Protein and miRNA Cancer Biomarkers using Silicon-Based Photonic Crystals and A Resonance Coupling Laser Scanning Platform

PubMed Central

George, Sherine; Chaudhery, Vikram; Lu, Meng; Takagi, Miki; Amro, Nabil; Pokhriyal, Anusha; Tan, Yafang; Ferreira, Placid; Cunningham, Brian T.

2013-01-01

Enhancement of the fluorescent output of surface-based fluorescence assays by performing them upon nanostructured photonic crystal (PC) surfaces has been demonstrated to increase signal intensities by >8000×. Using the multiplicative effects of optical resonant coupling to the PC in increasing the electric field intensity experienced by fluorescent labels (“enhanced excitation”) and the spatially biased funneling of fluorophore emissions through coupling to PC resonances (“enhanced extraction”), PC enhanced fluorescence (PCEF) can be adapted to reduce the limits of detection of disease biomarker assays, and to reduce the size and cost of high sensitivity detection instrumentation. In this work, we demonstrate the first silicon-based PCEF detection platform for multiplexed biomarker assay. The sensor in this platform is a silicon-based PC structure, comprised of a SiO2 grating that is overcoated with a thin film of high refractive index TiO2 and is produced in a semiconductor foundry for low cost, uniform, and reproducible manufacturing. The compact detection instrument that completes this platform was designed to efficiently couples fluorescence excitation from a semiconductor laser to the resonant optical modes of the PC, resulting in elevated electric field strength that is highly concentrated within the region <100 nm from the PC surface. This instrument utilizes a cylindrically focused line to scan a microarray in <1 minute. To demonstrate the capabilities of this sensor-detector platform, microspot fluorescent sandwich immunoassays using secondary antibodies labeled with Cy5 for two cancer biomarkers (TNF-α and IL-3) were performed. Biomarkers were detected at concentrations as low as 0.1 pM. In a fluorescent microarray for detection of a breast cancer miRNA biomarker miR-21, the miRNA was detectable at a concentration of 0.6 pM. PMID:23963502

EFFECTS OF MOVEABLE PLATFORM TRAINING IN PREVENTING SLIP-INDUCED FALLS IN OLDER ADULTS

PubMed Central

Parijat, Prakriti; Lockhart, Thurmon E

2011-01-01

Identifying effective interventions is vitalin preventing slip-induced fall accidents in older adults. The purpose of the current study was to evaluate the efficacy of moveable platform training in improving recovery reactions and reducing fall frequency in older adults. Twenty-four older adults were recruited and randomly assigned to two groups (training and control). Both groups underwent three sessions including baseline slip, training, and transfer of training on a slippery surface. Both groups experienced two slips on a slippery surface, one during the baseline and the other (after two weeks) during the transfer of training session. In the training session, the training group underwent twelve simulated slips using a moveable platform while the control group performed normal walking trials. Kinematic, kinetic, and EMG data were collected during all the sessions. Results indicated a reduced incidence of falls in the training group during the transfer of training trial as compared to the control group. The training group was able to transfer proactive and reactive control strategies learned during training to the second slip trial. The proactive adjustments include increased center-of-mass velocity and transitional acceleration after training. Reactive adjustments include reduction in muscle onset and time to peak activations of knee flexors and ankle plantarflexors, reduced ankle and knee coactivation, reduced slip displacement, and reduced time to peak knee flexion, trunk flexion, and hip flexion velocities. In general, the results indicated a beneficial effect of perturbation training in reducing slip severity and recovery kinematics in healthy older adults. PMID:22134467

Formation of composite polyacrylamide and silicone substrates for independent control of stiffness and strain.

PubMed

Simmons, Chelsey S; Ribeiro, Alexandre J S; Pruitt, Beth L

2013-02-21

Cells that line major tissues in the body such as blood vessels, lungs and gastrointestinal tract experience deformation from mechanical strain with our heartbeat, breathing, and other daily activities. Tissues also remodel in both development and disease, changing their mechanical properties. Taken together, cells can experience vastly different mechanical cues resulting from the combination of these interdependent stimuli. To date, most studies of cellular mechanotransduction have been limited to assays in which variations in substrate stiffness and strain were not combined. Here, we address this technological gap by implementing a method that can simultaneously tune both substrate stiffness and mechanical strain. Substrate stiffness is controlled with different monomer and crosslinker ratios during polyacrylamide gel polymerization, and strain is transferred from the underlying silicone platform when stretched. We demonstrate this platform with polyacrylamide gels with elastic moduli at 6 kPa and 20 kPa in combination with two different silicone formulations. The gels remain attached with up to 50% applied strains. To validate strain transfer through the gels into cells, we employ particle-tracking methods and observe strain transmission via cell morphological changes.

Formation of composite polyacrylamide and silicone substrates for independent control of stiffness and strain

PubMed Central

Simmons, Chelsey S.; Ribeiro, Alexandre J. S.; Pruitt, Beth L.

2013-01-01

Cells that line major tissues in the body such as blood vessels, lungs and gastrointestinal tract experience deformation from mechanical strain with our heartbeat, breathing, and other daily activities. Tissues also remodel in both development and disease, changing their mechanical properties. Taken together, cells can experience vastly different mechanical cues resulting from the combination of these interdependent stimuli. To date, most studies of cellular mechanotransduction have been limited to assays in which variations in substrate stiffness and strain were not combined. Here, we address this technological gap by implementing a method that can simultaneously tune both substrate stiffness and mechanical strain. Substrate stiffness is controlled with different monomer and crosslinker ratios during polyacrylamide gel polymerization, and strain is transferred from the underlying silicone platform when stretched. We demonstrate this platform with polyacrylamide gels with elastic moduli at 6 kPa and 20 kPa in combination with two different silicone formulations. The gels remain attached with up to 50% applied strains. To validate strain transfer through the gels into cells, we employ particle-tracking methods and observe strain transmission via cell morphological changes. PMID:23287818

Integrating photonics with silicon nanoelectronics for the next generation of systems on a chip.

PubMed

Atabaki, Amir H; Moazeni, Sajjad; Pavanello, Fabio; Gevorgyan, Hayk; Notaros, Jelena; Alloatti, Luca; Wade, Mark T; Sun, Chen; Kruger, Seth A; Meng, Huaiyu; Al Qubaisi, Kenaish; Wang, Imbert; Zhang, Bohan; Khilo, Anatol; Baiocco, Christopher V; Popović, Miloš A; Stojanović, Vladimir M; Ram, Rajeev J

2018-04-01

Electronic and photonic technologies have transformed our lives-from computing and mobile devices, to information technology and the internet. Our future demands in these fields require innovation in each technology separately, but also depend on our ability to harness their complementary physics through integrated solutions 1,2 . This goal is hindered by the fact that most silicon nanotechnologies-which enable our processors, computer memory, communications chips and image sensors-rely on bulk silicon substrates, a cost-effective solution with an abundant supply chain, but with substantial limitations for the integration of photonic functions. Here we introduce photonics into bulk silicon complementary metal-oxide-semiconductor (CMOS) chips using a layer of polycrystalline silicon deposited on silicon oxide (glass) islands fabricated alongside transistors. We use this single deposited layer to realize optical waveguides and resonators, high-speed optical modulators and sensitive avalanche photodetectors. We integrated this photonic platform with a 65-nanometre-transistor bulk CMOS process technology inside a 300-millimetre-diameter-wafer microelectronics foundry. We then implemented integrated high-speed optical transceivers in this platform that operate at ten gigabits per second, composed of millions of transistors, and arrayed on a single optical bus for wavelength division multiplexing, to address the demand for high-bandwidth optical interconnects in data centres and high-performance computing 3,4 . By decoupling the formation of photonic devices from that of transistors, this integration approach can achieve many of the goals of multi-chip solutions 5 , but with the performance, complexity and scalability of 'systems on a chip' 1,6-8 . As transistors smaller than ten nanometres across become commercially available 9 , and as new nanotechnologies emerge 10,11 , this approach could provide a way to integrate photonics with state-of-the-art nanoelectronics.

High surface area silicon materials: fundamentals and new technology.

PubMed

Buriak, Jillian M

2006-01-15

Crystalline silicon forms the basis of just about all computing technologies on the planet, in the form of microelectronics. An enormous amount of research infrastructure and knowledge has been developed over the past half-century to construct complex functional microelectronic structures in silicon. As a result, it is highly probable that silicon will remain central to computing and related technologies as a platform for integration of, for instance, molecular electronics, sensing elements and micro- and nanoelectromechanical systems. Porous nanocrystalline silicon is a fascinating variant of the same single crystal silicon wafers used to make computer chips. Its synthesis, a straightforward electrochemical, chemical or photochemical etch, is compatible with existing silicon-based fabrication techniques. Porous silicon literally adds an entirely new dimension to the realm of silicon-based technologies as it has a complex, three-dimensional architecture made up of silicon nanoparticles, nanowires, and channel structures. The intrinsic material is photoluminescent at room temperature in the visible region due to quantum confinement effects, and thus provides an optical element to electronic applications. Our group has been developing new organic surface reactions on porous and nanocrystalline silicon to tailor it for a myriad of applications, including molecular electronics and sensing. Integration of organic and biological molecules with porous silicon is critical to harness the properties of this material. The construction and use of complex, hierarchical molecular synthetic strategies on porous silicon will be described.

Utilizing Technology for FCS Education: Selecting Appropriate Interactive Webinar Software

ERIC Educational Resources Information Center

Zoumenou, Virginie; Sigman-Grant, Madeleine; Coleman, Gayle; Malekian, Fatemeh; Zee, Julia M. K.; Fountain, Brent J.; Marsh, Akela

2015-01-01

The purpose of this research was to identify commonly used interactive webinar software platforms and to conduct a testing session on best practices related to an interactive webinar. The study employed the Adobe Connect and the Maestro Conference platforms. The 15 participants experienced five best practices: pre-work, polling, breakout room,…

User recruitment, training, and support at NOAO Data Lab

NASA Astrophysics Data System (ADS)

Nikutta, Robert; Fitzpatrick, Michael J.; NOAO Data Lab

2018-06-01

The NOAO Data Lab (datalab.noao.edu) is a fully-fledged science data & analysis platform. However, simply building a science platform is notenough to declare it a success. Like any such system built for users, it needs actual users who see enough value in it to be willing toovercome the inertia of registering an account, studying the documentation, working through examples, and ultimately attempting tosolve their own science problems using the platform. The NOAO Data Lab has been open to users since June 2016. In this past year we haveregistered hundreds of users and improved the system, not least through the interaction with and feedback from our users. The posterwill delineate our efforts to recruit new users through conference presentations, platform demos and user workshops, and what we do toassure that users experience their first steps and their learning process with Data Lab as easy, competent, and inspiring. It will alsopresent our efforts in user retention and user support, from a human-staffed helpdesk, to one-on-one sessions, to regular"bring-your-own-problem (BYOP)" in-house sessions with interested users.

Correlative imaging across microscopy platforms using the fast and accurate relocation of microscopic experimental regions (FARMER) method

NASA Astrophysics Data System (ADS)

Huynh, Toan; Daddysman, Matthew K.; Bao, Ying; Selewa, Alan; Kuznetsov, Andrey; Philipson, Louis H.; Scherer, Norbert F.

2017-05-01

Imaging specific regions of interest (ROIs) of nanomaterials or biological samples with different imaging modalities (e.g., light and electron microscopy) or at subsequent time points (e.g., before and after off-microscope procedures) requires relocating the ROIs. Unfortunately, relocation is typically difficult and very time consuming to achieve. Previously developed techniques involve the fabrication of arrays of features, the procedures for which are complex, and the added features can interfere with imaging the ROIs. We report the Fast and Accurate Relocation of Microscopic Experimental Regions (FARMER) method, which only requires determining the coordinates of 3 (or more) conspicuous reference points (REFs) and employs an algorithm based on geometric operators to relocate ROIs in subsequent imaging sessions. The 3 REFs can be quickly added to various regions of a sample using simple tools (e.g., permanent markers or conductive pens) and do not interfere with the ROIs. The coordinates of the REFs and the ROIs are obtained in the first imaging session (on a particular microscope platform) using an accurate and precise encoded motorized stage. In subsequent imaging sessions, the FARMER algorithm finds the new coordinates of the ROIs (on the same or different platforms), using the coordinates of the manually located REFs and the previously recorded coordinates. FARMER is convenient, fast (3-15 min/session, at least 10-fold faster than manual searches), accurate (4.4 μm average error on a microscope with a 100x objective), and precise (almost all errors are <8 μm), even with deliberate rotating and tilting of the sample well beyond normal repositioning accuracy. We demonstrate this versatility by imaging and re-imaging a diverse set of samples and imaging methods: live mammalian cells at different time points; fixed bacterial cells on two microscopes with different imaging modalities; and nanostructures on optical and electron microscopes. FARMER can be readily adapted to any imaging system with an encoded motorized stage and can facilitate multi-session and multi-platform imaging experiments in biology, materials science, photonics, and nanoscience.

Six-beam homodyne laser Doppler vibrometry based on silicon photonics technology.

PubMed

Li, Yanlu; Zhu, Jinghao; Duperron, Matthieu; O'Brien, Peter; Schüler, Ralf; Aasmul, Soren; de Melis, Mirko; Kersemans, Mathias; Baets, Roel

2018-02-05

This paper describes an integrated six-beam homodyne laser Doppler vibrometry (LDV) system based on a silicon-on-insulator (SOI) full platform technology, with on-chip photo-diodes and phase modulators. Electronics and optics are also implemented around the integrated photonic circuit (PIC) to enable a simultaneous six-beam measurement. Measurement of a propagating guided elastic wave in an aluminum plate (speed ≈ 909 m/s @ 61.5 kHz) is demonstrated.

High-performance silicon photonics technology for telecommunications applications.

PubMed

Yamada, Koji; Tsuchizawa, Tai; Nishi, Hidetaka; Kou, Rai; Hiraki, Tatsurou; Takeda, Kotaro; Fukuda, Hiroshi; Ishikawa, Yasuhiko; Wada, Kazumi; Yamamoto, Tsuyoshi

2014-04-01

By way of a brief review of Si photonics technology, we show that significant improvements in device performance are necessary for practical telecommunications applications. In order to improve device performance in Si photonics, we have developed a Si-Ge-silica monolithic integration platform, on which compact Si-Ge-based modulators/detectors and silica-based high-performance wavelength filters are monolithically integrated. The platform features low-temperature silica film deposition, which cannot damage Si-Ge-based active devices. Using this platform, we have developed various integrated photonic devices for broadband telecommunications applications.

High-performance silicon photonics technology for telecommunications applications

PubMed Central

Yamada, Koji; Tsuchizawa, Tai; Nishi, Hidetaka; Kou, Rai; Hiraki, Tatsurou; Takeda, Kotaro; Fukuda, Hiroshi; Ishikawa, Yasuhiko; Wada, Kazumi; Yamamoto, Tsuyoshi

2014-01-01

By way of a brief review of Si photonics technology, we show that significant improvements in device performance are necessary for practical telecommunications applications. In order to improve device performance in Si photonics, we have developed a Si-Ge-silica monolithic integration platform, on which compact Si-Ge–based modulators/detectors and silica-based high-performance wavelength filters are monolithically integrated. The platform features low-temperature silica film deposition, which cannot damage Si-Ge–based active devices. Using this platform, we have developed various integrated photonic devices for broadband telecommunications applications. PMID:27877659

High-performance silicon photonics technology for telecommunications applications

NASA Astrophysics Data System (ADS)

Yamada, Koji; Tsuchizawa, Tai; Nishi, Hidetaka; Kou, Rai; Hiraki, Tatsurou; Takeda, Kotaro; Fukuda, Hiroshi; Ishikawa, Yasuhiko; Wada, Kazumi; Yamamoto, Tsuyoshi

2014-04-01

By way of a brief review of Si photonics technology, we show that significant improvements in device performance are necessary for practical telecommunications applications. In order to improve device performance in Si photonics, we have developed a Si-Ge-silica monolithic integration platform, on which compact Si-Ge-based modulators/detectors and silica-based high-performance wavelength filters are monolithically integrated. The platform features low-temperature silica film deposition, which cannot damage Si-Ge-based active devices. Using this platform, we have developed various integrated photonic devices for broadband telecommunications applications.

Technology & Disability: Research, Design, Practice, and Policy. Proceedings of the RESNA International Conference (25th, Minneapolis, Minnesota, June 27-July 1, 2002).

ERIC Educational Resources Information Center

Simpson, Richard, Ed.

These proceedings of the 2002 annual RESNA (Association for the Advancement of Rehabilitation Technology) conference include more than 200 presentations on all facets of assistive technology, including concurrent sessions, scientific platform sessions, interactive poster presentations, computer demonstrations, and the research symposium. The…

Real-Time and In-Flow Sensing Using a High Sensitivity Porous Silicon Microcavity-Based Sensor.

PubMed

Caroselli, Raffaele; Martín Sánchez, David; Ponce Alcántara, Salvador; Prats Quilez, Francisco; Torrijos Morán, Luis; García-Rupérez, Jaime

2017-12-05

Porous silicon seems to be an appropriate material platform for the development of high-sensitivity and low-cost optical sensors, as their porous nature increases the interaction with the target substances, and their fabrication process is very simple and inexpensive. In this paper, we present the experimental development of a porous silicon microcavity sensor and its use for real-time in-flow sensing application. A high-sensitivity configuration was designed and then fabricated, by electrochemically etching a silicon wafer. Refractive index sensing experiments were realized by flowing several dilutions with decreasing refractive indices, and measuring the spectral shift in real-time. The porous silicon microcavity sensor showed a very linear response over a wide refractive index range, with a sensitivity around 1000 nm/refractive index unit (RIU), which allowed us to directly detect refractive index variations in the 10 -7 RIU range.

III-V quantum light source and cavity-QED on silicon.

PubMed

Luxmoore, I J; Toro, R; Del Pozo-Zamudio, O; Wasley, N A; Chekhovich, E A; Sanchez, A M; Beanland, R; Fox, A M; Skolnick, M S; Liu, H Y; Tartakovskii, A I

2013-01-01

Non-classical light sources offer a myriad of possibilities in both fundamental science and commercial applications. Single photons are the most robust carriers of quantum information and can be exploited for linear optics quantum information processing. Scale-up requires miniaturisation of the waveguide circuit and multiple single photon sources. Silicon photonics, driven by the incentive of optical interconnects is a highly promising platform for the passive optical components, but integrated light sources are limited by silicon's indirect band-gap. III-V semiconductor quantum-dots, on the other hand, are proven quantum emitters. Here we demonstrate single-photon emission from quantum-dots coupled to photonic crystal nanocavities fabricated from III-V material grown directly on silicon substrates. The high quality of the III-V material and photonic structures is emphasized by observation of the strong-coupling regime. This work opens-up the advantages of silicon photonics to the integration and scale-up of solid-state quantum optical systems.

Software-defined networking control plane for seamless integration of multiple silicon photonic switches in Datacom networks

DOE PAGES

Shen, Yiwen; Hattink, Maarten; Samadi, Payman; ...

2018-04-13

Silicon photonics based switches offer an effective option for the delivery of dynamic bandwidth for future large-scale Datacom systems while maintaining scalable energy efficiency. The integration of a silicon photonics-based optical switching fabric within electronic Datacom architectures requires novel network topologies and arbitration strategies to effectively manage the active elements in the network. Here, we present a scalable software-defined networking control plane to integrate silicon photonic based switches with conventional Ethernet or InfiniBand networks. Our software-defined control plane manages both electronic packet switches and multiple silicon photonic switches for simultaneous packet and circuit switching. We built an experimental Dragonfly networkmore » testbed with 16 electronic packet switches and 2 silicon photonic switches to evaluate our control plane. Observed latencies occupied by each step of the switching procedure demonstrate a total of 344 microsecond control plane latency for data-center and high performance computing platforms.« less

Software-defined networking control plane for seamless integration of multiple silicon photonic switches in Datacom networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Yiwen; Hattink, Maarten; Samadi, Payman

Silicon photonics based switches offer an effective option for the delivery of dynamic bandwidth for future large-scale Datacom systems while maintaining scalable energy efficiency. The integration of a silicon photonics-based optical switching fabric within electronic Datacom architectures requires novel network topologies and arbitration strategies to effectively manage the active elements in the network. Here, we present a scalable software-defined networking control plane to integrate silicon photonic based switches with conventional Ethernet or InfiniBand networks. Our software-defined control plane manages both electronic packet switches and multiple silicon photonic switches for simultaneous packet and circuit switching. We built an experimental Dragonfly networkmore » testbed with 16 electronic packet switches and 2 silicon photonic switches to evaluate our control plane. Observed latencies occupied by each step of the switching procedure demonstrate a total of 344 microsecond control plane latency for data-center and high performance computing platforms.« less

Graphene-assisted ultra-compact polarization splitter and rotator with an extended bandwidth.

PubMed

Zhang, Tian; Ke, Xianmin; Yin, Xiang; Chen, Lin; Li, Xun

2017-09-22

The high refraction-index contrast between silicon and the surrounding cladding makes silicon-on-insulator devices highly polarization-dependent. However, it is greatly desirable for many applications to address the issue of polarization dependence in silicon photonics. Here, a novel ultra-compact polarization splitter and rotator (PSR), constructed with an asymmetrical directional coupler consisting of a rib silicon waveguide and a graphene-embedded rib silicon waveguide (GERSW), on a silicon-on-insulator platform is proposed and investigated. By taking advantage of the large modulation of the effective refractive index of the TE mode for the GERSW by tuning the chemical potential of graphene, the phase matching condition can be well satisfied over a wide spectral band. The presented result demonstrates that for a 7-layer-graphene-embedded PSR with a coupling length of 11.1 μm, a high TM-to-TE conversion efficiency (>-0.5 dB) can be achieved over a broad bandwidth from 1516 to 1602 nm.

Photonic Crystal Sensors Based on Porous Silicon

PubMed Central

Pacholski, Claudia

2013-01-01

Porous silicon has been established as an excellent sensing platform for the optical detection of hazardous chemicals and biomolecular interactions such as DNA hybridization, antigen/antibody binding, and enzymatic reactions. Its porous nature provides a high surface area within a small volume, which can be easily controlled by changing the pore sizes. As the porosity and consequently the refractive index of an etched porous silicon layer depends on the electrochemial etching conditions photonic crystals composed of multilayered porous silicon films with well-resolved and narrow optical reflectivity features can easily be obtained. The prominent optical response of the photonic crystal decreases the detection limit and therefore increases the sensitivity of porous silicon sensors in comparison to sensors utilizing Fabry-Pérot based optical transduction. Development of porous silicon photonic crystal sensors which allow for the detection of analytes by the naked eye using a simple color change or the fabrication of stacked porous silicon photonic crystals showing two distinct optical features which can be utilized for the discrimination of analytes emphasize its high application potential. PMID:23571671

High-speed and on-chip graphene blackbody emitters for optical communications by remote heat transfer.

PubMed

Miyoshi, Yusuke; Fukazawa, Yusuke; Amasaka, Yuya; Reckmann, Robin; Yokoi, Tomoya; Ishida, Kazuki; Kawahara, Kenji; Ago, Hiroki; Maki, Hideyuki

2018-03-29

High-speed light emitters integrated on silicon chips can enable novel architectures for silicon-based optoelectronics, such as on-chip optical interconnects, and silicon photonics. However, conventional light sources based on compound semiconductors face major challenges for their integration with a silicon-based platform because of their difficulty of direct growth on a silicon substrate. Here we report ultra-high-speed (100-ps response time), highly integrated graphene-based on-silicon-chip blackbody emitters in the near-infrared region including telecommunication wavelength. Their emission responses are strongly affected by the graphene contact with the substrate depending on the number of graphene layers. The ultra-high-speed emission can be understood by remote quantum thermal transport via surface polar phonons of the substrates. We demonstrated real-time optical communications, integrated two-dimensional array emitters, capped emitters operable in air, and the direct coupling of optical fibers to the emitters. These emitters can open new routes to on-Si-chip, small footprint, and high-speed emitters for highly integrated optoelectronics and silicon photonics.

Kinetics of new thermal donors (NTDs) in CZ-silicon based on FTIR analysis

NASA Astrophysics Data System (ADS)

Singh, Rajeev; Singh, Shyam; Yadav, Bal Chandra

2018-05-01

Oxygen is quite friendly to silicon and is interstitially positioned well guarded by neighbouring silicon atoms on regular sites, provides mechanical strength to the silicon wafers and helps in internal gettering. Oxygen dimers are a fast diffusing species. Presence of trimers provides a wider platform for interconversion of dimer-trimer and V-O interaction. Oxygen atoms in isomeric positions really play a trick in the formation of TDD0 - TDD16. Other members of the donor species are likely due to the addition of dimers/trimers. FTIR analysis of boron-doped CZ-silicon annealed at 495 °C revealed a unique feature that the nature of 999 cm-1 absorption peak corresponding to TDD3 is contrary to 1107 cm-1 absorption peak corresponding to interstitial oxygen in silicon. Isothermal annealing at different temperatures also indicates slow disappearance of one donor species and emergence of other donor species. Thermal acceptors and recombination centers intrinsically present in the as grown silicon crystal and/or generated as a result of annealing do contribute to lower the donor concentration.

Silicon Alignment Pins: An Easy Way to Realize a Wafer-to-Wafer Alignment

NASA Technical Reports Server (NTRS)

Jung-Kubiak, Cecile; Reck, Theodore J.; Lin, Robert H.; Peralta, Alejandro; Gill, John J.; Lee, Choonsup; Siles, Jose; Toda, Risaku; Chattopadhyay, Goutam; Cooper, Ken B.;

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ji, Xiaoyu; Lei, Shiming; Yu, Shih -Ying

Semiconductor core optical fibers with a silica cladding are of great interest in nonlinear photonics and optoelectronics applications. Laser crystallization has been recently demonstrated for crystallizing amorphous silicon fibers into crystalline form. Here we explore the underlying mechanism by which long single-crystal silicon fibers, which are novel platforms for silicon photonics, can be achieved by this process. Using finite element modeling, we construct a laser processing diagram that reveals a parameter space within which single crystals can be grown. Utilizing this diagram, we illustrate the creation of single-crystal silicon core fibers by laser crystallizing amorphous silicon deposited inside silica capillarymore » fibers by high-pressure chemical vapor deposition. The single-crystal fibers, up to 5.1 mm long, have a very welldefined core/cladding interface and a chemically pure silicon core that leads to very low optical losses down to ~0.47-1dB/cm at the standard telecommunication wavelength (1550 nm). Furthermore, tt also exhibits a photosensitivity that is comparable to bulk silicon. Creating such laser processing diagrams can provide a general framework for developing single-crystal fibers in other materials of technological importance.« less

Waveguide silicon nitride grating coupler

NASA Astrophysics Data System (ADS)

Litvik, Jan; Dolnak, Ivan; Dado, Milan

2016-12-01

Grating couplers are one of the most used elements for coupling of light between optical fibers and photonic integrated components. Silicon-on-insulator platform provides strong confinement of light and allows high integration. In this work, using simulations we have designed a broadband silicon nitride surface grating coupler. The Fourier-eigenmode expansion and finite difference time domain methods are utilized in design optimization of grating coupler structure. The fully, single etch step grating coupler is based on a standard silicon-on-insulator wafer with 0.55 μm waveguide Si3N4 layer. The optimized structure at 1550 nm wavelength yields a peak coupling efficiency -2.6635 dB (54.16%) with a 1-dB bandwidth up to 80 nm. It is promising way for low-cost fabrication using complementary metal-oxide- semiconductor fabrication process.

Polymer waveguides for electro-optical integration in data centers and high-performance computers.

PubMed

Dangel, Roger; Hofrichter, Jens; Horst, Folkert; Jubin, Daniel; La Porta, Antonio; Meier, Norbert; Soganci, Ibrahim Murat; Weiss, Jonas; Offrein, Bert Jan

2015-02-23

To satisfy the intra- and inter-system bandwidth requirements of future data centers and high-performance computers, low-cost low-power high-throughput optical interconnects will become a key enabling technology. To tightly integrate optics with the computing hardware, particularly in the context of CMOS-compatible silicon photonics, optical printed circuit boards using polymer waveguides are considered as a formidable platform. IBM Research has already demonstrated the essential silicon photonics and interconnection building blocks. A remaining challenge is electro-optical packaging, i.e., the connection of the silicon photonics chips with the system. In this paper, we present a new single-mode polymer waveguide technology and a scalable method for building the optical interface between silicon photonics chips and single-mode polymer waveguides.

Wideband nonlinear spectral broadening in ultra-short ultra - silicon rich nitride waveguides.

PubMed

Choi, Ju Won; Chen, George F R; Ng, D K T; Ooi, Kelvin J A; Tan, Dawn T H

2016-06-08

CMOS-compatible nonlinear optics platforms with high Kerr nonlinearity facilitate the generation of broadband spectra based on self-phase modulation. Our ultra - silicon rich nitride (USRN) platform is designed to have a large nonlinear refractive index and low nonlinear losses at 1.55 μm for the facilitation of wideband spectral broadening. We investigate the ultrafast spectral characteristics of USRN waveguides with 1-mm-length, which have high nonlinear parameters (γ ∼ 550 W(-1)/m) and anomalous dispersion at 1.55 μm wavelength of input light. USRN add-drop ring resonators broaden output spectra by a factor of 2 compared with the bandwidth of input fs laser with the highest quality factors of 11000 and 15000. Two - fold self phase modulation induced spectral broadening is observed using waveguides only 430 μm in length, whereas a quadrupling of the output bandwidth is observed with USRN waveguides with a 1-mm-length. A broadening factor of around 3 per 1 mm length is achieved in the USRN waveguides, a value which is comparatively larger than many other CMOS-compatible platforms.

Laser fabrication of porous silicon-based platforms for cell culturing.

PubMed

Peláez, Ramón-J; Afonso, Carmen-N; Vega, Fidel; Recio-Sánchez, Gonzalo; Torres-Costa, Vicente; Manso-Silván, Miguel; García-Ruiz, Josefa-P; Martín-Palma, Raúl-J

2013-11-01

In this study, we explore the selective culturing of human mesenchymal stem cells (hMSCs) on Si-based diffractive platforms. We demonstrate a single-step and flexible method for producing platforms on nanostructured porous silicon (nanoPS) based on the use of single pulses of an excimer laser to expose phase masks. The resulting patterns are typically 1D patterns formed by fringes or 2D patterns formed by circles. They are formed by alternate regions of almost unmodified nanoPS and regions where the nanoPS surface has melted and transformed into Si nanoparticles. The patterns are produced in relatively large areas (a few square millimeters) and can have a wide range of periodicities and aspect ratios. Direct binding, that is, with no previous functionalization of the pattern, alignment, and active polarization of hMSCs are explored. The results show the preferential direct binding of the hMSCs along the transformed regions whenever their width compares with the dimensions of the cells and they escape from patterns for smaller widths suggesting that the selectivity can be tailored through the pattern period. Copyright © 2013 Wiley Periodicals, Inc.

Adiabatic Nanofocusing in Hybrid Gap Plasmon Waveguides on the Silicon-on-Insulator Platform.

PubMed

Nielsen, Michael P; Lafone, Lucas; Rakovich, Aliaksandra; Sidiropoulos, Themistoklis P H; Rahmani, Mohsen; Maier, Stefan A; Oulton, Rupert F

2016-02-10

We present an experimental demonstration of a new class of hybrid gap plasmon waveguides on the silicon-on-insulator (SOI) platform. Created by the hybridization of the plasmonic mode of a gap in a thin metal sheet and the transverse-electric (TE) photonic mode of an SOI slab, this waveguide is designed for efficient adiabatic nanofocusing simply by varying the gap width. For gap widths greater than 100 nm, the mode is primarily photonic in character and propagation lengths can be many tens of micrometers. For gap widths below 100 nm, the mode becomes plasmonic in character with field confinement predominantly within the gap region and with propagation lengths of a few microns. We estimate the electric field intensity enhancement in hybrid gap plasmon waveguide tapers at 1550 nm by three-photon absorption of selectively deposited CdSe/ZnS quantum dots within the gap. Here, we show electric field intensity enhancements of up to 167 ± 26 for a 24 nm gap, proving the viability of low loss adiabatic nanofocusing on a commercially relevant photonics platform.

Integrating cell on chip—Novel waveguide platform employing ultra-long optical paths

NASA Astrophysics Data System (ADS)

Fohrmann, Lena Simone; Sommer, Gerrit; Pitruzzello, Giampaolo; Krauss, Thomas F.; Petrov, Alexander Yu.; Eich, Manfred

2017-09-01

Optical waveguides are the most fundamental building blocks of integrated optical circuits. They are extremely well understood, yet there is still room for surprises. Here, we introduce a novel 2D waveguide platform which affords a strong interaction of the evanescent tail of a guided optical wave with an external medium while only employing a very small geometrical footprint. The key feature of the platform is its ability to integrate the ultra-long path lengths by combining low propagation losses in a silicon slab with multiple reflections of the guided wave from photonic crystal (PhC) mirrors. With a reflectivity of 99.1% of our tailored PhC-mirrors, we achieve interaction paths of 25 cm within an area of less than 10 mm2. This corresponds to 0.17 dB/cm effective propagation which is much lower than the state-of-the-art loss of approximately 1 dB/cm of single mode silicon channel waveguides. In contrast to conventional waveguides, our 2D-approach leads to a decay of the guided wave power only inversely proportional to the optical path length. This entirely different characteristic is the major advantage of the 2D integrating cell waveguide platform over the conventional channel waveguide concepts that obey the Beer-Lambert law.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, William; Xiong, Chi; Khater, Marwan

Due to the high radiative forcing of methane, fugitive natural gas leaks pose a significant challenge to the near-term environmental viability of oil and gas extraction. Reducing the subsequent environmental impact requires cost-effective sensor nodes for reliable, rapid, and continuous identification of extraneous methane emissions. The efficacy of laser spectroscopy has been widely demonstrated in both environmental and medical applications due to its sensitivity and specificity to the target analyte. However, the present cost and the lack of manufacturing scalability of free-space optical systems can limit their viability for economical wide-area sensor networks in localized leak detection applications. In thismore » paper, we will review the development and performance of a cost-effective silicon photonic sensing platform. This platform uses silicon photonic waveguide and packaging integration technologies to enable on-chip evanescent field spectroscopy of methane.« less

Optical MEMS platform for low-cost on-chip integration of planar light circuits and optical switching

NASA Astrophysics Data System (ADS)

German, Kristine A.; Kubby, Joel; Chen, Jingkuang; Diehl, James; Feinberg, Kathleen; Gulvin, Peter; Herko, Larry; Jia, Nancy; Lin, Pinyen; Liu, Xueyuan; Ma, Jun; Meyers, John; Nystrom, Peter; Wang, Yao Rong

2004-07-01

Xerox Corporation has developed a technology platform for on-chip integration of latching MEMS optical waveguide switches and Planar Light Circuit (PLC) components using a Silicon On Insulator (SOI) based process. To illustrate the current state of this new technology platform, working prototypes of a Reconfigurable Optical Add/Drop Multiplexer (ROADM) and a l-router will be presented along with details of the integrated latching MEMS optical switches. On-chip integration of optical switches and PLCs can greatly reduce the size, manufacturing cost and operating cost of multi-component optical equipment. It is anticipated that low-cost, low-overhead optical network products will accelerate the migration of functions and services from high-cost long-haul markets to price sensitive markets, including networks for metropolitan areas and fiber to the home. Compared to the more common silica-on-silicon PLC technology, the high index of refraction of silicon waveguides created in the SOI device layer enables miniaturization of optical components, thereby increasing yield and decreasing cost projections. The latching SOI MEMS switches feature moving waveguides, and are advantaged across multiple attributes relative to alternative switching technologies, such as thermal optical switches and polymer switches. The SOI process employed was jointly developed under the auspice of the NIST APT program in partnership with Coventor, Corning IntelliSense Corp., and MicroScan Systems to enable fabrication of a broad range of free space and guided wave MicroOptoElectroMechanical Systems (MOEMS).

Last Advances in Silicon-Based Optical Biosensors.

PubMed

Fernández Gavela, Adrián; Grajales García, Daniel; Ramirez, Jhonattan C; Lechuga, Laura M

2016-02-24

We review the most important achievements published in the last five years in the field of silicon-based optical biosensors. We focus specially on label-free optical biosensors and their implementation into lab-on-a-chip platforms, with an emphasis on developments demonstrating the capability of the devices for real bioanalytical applications. We report on novel transducers and materials, improvements of existing transducers, new and improved biofunctionalization procedures as well as the prospects for near future commercialization of these technologies.

Reconfigurable and tunable compact comb filter and (de)interleaver on silicon platform.

PubMed

Zhou, Nan; Zheng, Shuang; Long, Yun; Ruan, Zhengsen; Shen, Li; Wang, Jian

2018-02-19

We propose and demonstrate a reconfigurable and tunable chip-scale comb filter and (de)interleaver on a silicon platform. The silicon-based photonic integrated device is formed by Sagnac loop mirrors (SLMs) with directional couplers replaced by multi-mode interference (MMI) assisted tunable Mach-Zehnder interferometer (MZI) couplers. The device can be regarded as a large SLM incorporating two small SLMs which form a Fabry-Perot (FP) cavity. By appropriately adjusting the micro-heaters in tunable MZI couplers and cavity, switchable operation between comb filter and (de)interleaver and extinction ratio and wavelength tunable operations of comb filter and (de)interleaver are achievable by thermo-optic tuning. Reconfigurable comb filter and (de)interleaver is demonstrated in the experiment. The central wavelength shifts of comb filter and (de)interleaver are demonstrated with wavelength tuning efficiencies of ~0.0224 nm/mW and ~0.0193 nm/mW, respectively. The 3-dB bandwidth of the comb filter is ~0.032 nm. The 3-dB and 20-dB bandwidths of the (de)interleaver passband are ~0.225 nm and ~0.326 nm. The obtained results indicate that the designed and fabricated device provides switchable comb filtering and interleaving functions together with extinction ratio and wavelength tunabilities. Reconfigurable and tunable silicon-based comb filter and (de)interleaver may find potential applications in robust wavelength-division multiplexing (WDM) optical communication systems.

Exploiting HPC Platforms for Metagenomics: Challenges and Opportunities (MICW - Metagenomics Informatics Challenges Workshop: 10K Genomes at a Time)

ScienceCinema

Canon, Shane

2018-01-24

DOE JGI's Zhong Wang, chair of the High-performance Computing session, gives a brief introduction before Berkeley Lab's Shane Canon talks about "Exploiting HPC Platforms for Metagenomics: Challenges and Opportunities" at the Metagenomics Informatics Challenges Workshop held at the DOE JGI on October 12-13, 2011.

Single-crystal silicon optical fiber by direct laser crystallization

DOE PAGES

Ji, Xiaoyu; Lei, Shiming; Yu, Shih -Ying; ...

2016-12-05

Semiconductor core optical fibers with a silica cladding are of great interest in nonlinear photonics and optoelectronics applications. Laser crystallization has been recently demonstrated for crystallizing amorphous silicon fibers into crystalline form. Here we explore the underlying mechanism by which long single-crystal silicon fibers, which are novel platforms for silicon photonics, can be achieved by this process. Using finite element modeling, we construct a laser processing diagram that reveals a parameter space within which single crystals can be grown. Utilizing this diagram, we illustrate the creation of single-crystal silicon core fibers by laser crystallizing amorphous silicon deposited inside silica capillarymore » fibers by high-pressure chemical vapor deposition. The single-crystal fibers, up to 5.1 mm long, have a very welldefined core/cladding interface and a chemically pure silicon core that leads to very low optical losses down to ~0.47-1dB/cm at the standard telecommunication wavelength (1550 nm). Furthermore, tt also exhibits a photosensitivity that is comparable to bulk silicon. Creating such laser processing diagrams can provide a general framework for developing single-crystal fibers in other materials of technological importance.« less

Monolithic integration of a silica AWG and Ge photodiodes on Si photonic platform for one-chip WDM receiver.

PubMed

Nishi, Hidetaka; Tsuchizawa, Tai; Kou, Rai; Shinojima, Hiroyuki; Yamada, Takashi; Kimura, Hideaki; Ishikawa, Yasuhiko; Wada, Kazumi; Yamada, Koji

2012-04-09

On the silicon (Si) photonic platform, we monolithically integrated a silica-based arrayed-waveguide grating (AWG) and germanium (Ge) photodiodes (PDs) using low-temperature fabrication technology. We confirmed demultiplexing by the AWG, optical-electrical signal conversion by Ge PDs, and high-speed signal detection at all channels. In addition, we mounted a multichannel transimpedance amplifier/limiting amplifier (TIA/LA) circuit on the fabricated AWG-PD device using flip-chip bonding technology. The results show the promising potential of our Si photonic platform as a photonics-electronics convergence.

Fiber laser platform for highest flexibility and reliability in industrial femtosecond micromachining: TruMicro Series 2000

NASA Astrophysics Data System (ADS)

Jansen, Florian; Kanal, Florian; Kahmann, Max; Tan, Chuong; Diekamp, Holger; Scelle, Raphael; Budnicki, Aleksander; Sutter, Dirk

2018-02-01

In this work we present an ultrafast laser system distinguished by its industry-ready reliability and its outstanding flexibility that allows for real-time process-inherent parameter. The robust system design and linear amplifier architecture make the all-fiber series TruMicro 2000 ideally suited for passive coupling to hollow-core delivery fibers. In addition to details on the laser system itself, various application examples are shown, including welding of different glasses and ablation of silicon carbide and silicon.

Realizing topological edge states in a silicon nitride microring-based photonic integrated circuit.

PubMed

Yin, Chenxuan; Chen, Yujie; Jiang, Xiaohui; Zhang, Yanfeng; Shao, Zengkai; Xu, Pengfei; Yu, Siyuan

2016-10-15

Topological edge states in a photonic integrated circuit based on the platform of silicon nitride are demonstrated with a two-dimensional coupled resonator optical waveguide array involving the synthetic magnetic field for photons at near-infrared wavelengths. Measurements indicate that the topological edge states can be observed at certain wavelengths, with light travelling around the boundary of the array. Combined with the induced disorders in fabrication near the edge, the system shows the defect immunity under the topological protection of edge states.

Thermal Management Investigations in Ceramic Thin Disk Lasers

DTIC Science & Technology

2011-01-14

techniques. 10-14mm diameter 0.2mm thick disks are mounted on silicon carbide ( SiC ), sapphire, and diamond submounts. From a larger platform, more than 6kW...along with various cooling techniques. 10-14mm diameter O.2mm thick disks are mounted on silicon carbide ( SiC ), sapphire, and diamond submounts. From a...assemblies are either attached to heat sinks or directly to the Cu W cooling mount, see Fig. I (c) & (d). The heat sinks tested are SiC , sapphire, and

Silicon-on-insulator sensors using integrated resonance-enhanced defect-mediated photodetectors.

PubMed

Fard, Sahba Talebi; Murray, Kyle; Caverley, Michael; Donzella, Valentina; Flueckiger, Jonas; Grist, Samantha M; Huante-Ceron, Edgar; Schmidt, Shon A; Kwok, Ezra; Jaeger, Nicolas A F; Knights, Andrew P; Chrostowski, Lukas

2014-11-17

A resonance-enhanced, defect-mediated, ring resonator photodetector has been implemented as a single unit biosensor on a silicon-on-insulator platform, providing a cost effective means of integrating ring resonator sensors with photodetectors for lab-on-chip applications. This method overcomes the challenge of integrating hybrid photodetectors on the chip. The demonstrated responsivity of the photodetector-sensor was 90 mA/W. Devices were characterized using refractive index modified solutions and showed sensitivities of 30 nm/RIU.

Last Advances in Silicon-Based Optical Biosensors

PubMed Central

Fernández Gavela, Adrián; Grajales García, Daniel; Ramirez, Jhonattan C.; Lechuga, Laura M.

2016-01-01

We review the most important achievements published in the last five years in the field of silicon-based optical biosensors. We focus specially on label-free optical biosensors and their implementation into lab-on-a-chip platforms, with an emphasis on developments demonstrating the capability of the devices for real bioanalytical applications. We report on novel transducers and materials, improvements of existing transducers, new and improved biofunctionalization procedures as well as the prospects for near future commercialization of these technologies. PMID:26927105

From Extraterrestrial to Terrestrial Applications

NASA Astrophysics Data System (ADS)

Strobl, G. F. X.; Laroche, G.; Rasch, K.-D.; Hey, G.

While working to improve transistors in the early 1950s, Bell scientists Gerald Pearson and Calvin Fuller invented the first silicon solar cell. In 1954 Bell Laboratories presented the first solar battery to the public. Despite some early applications on oil platforms, the astronomical price of the cells limited their use to space exploration. In 1958 Vanguard 1, the first satellite with solar cells aboard, went into orbit. As the space program advanced, silicon solar cells became the preferred power source for spacecraft.

Realization of a Hole-Doped Mott Insulator on a Triangular Silicon Lattice

NASA Astrophysics Data System (ADS)

Ming, Fangfei; Johnston, Steve; Mulugeta, Daniel; Smith, Tyler S.; Vilmercati, Paolo; Lee, Geunseop; Maier, Thomas A.; Snijders, Paul C.; Weitering, Hanno H.

2017-12-01

The physics of doped Mott insulators is at the heart of some of the most exotic physical phenomena in materials research including insulator-metal transitions, colossal magnetoresistance, and high-temperature superconductivity in layered perovskite compounds. Advances in this field would greatly benefit from the availability of new material systems with a similar richness of physical phenomena but with fewer chemical and structural complications in comparison to oxides. Using scanning tunneling microscopy and spectroscopy, we show that such a system can be realized on a silicon platform. The adsorption of one-third monolayer of Sn atoms on a Si(111) surface produces a triangular surface lattice with half filled dangling bond orbitals. Modulation hole doping of these dangling bonds unveils clear hallmarks of Mott physics, such as spectral weight transfer and the formation of quasiparticle states at the Fermi level, well-defined Fermi contour segments, and a sharp singularity in the density of states. These observations are remarkably similar to those made in complex oxide materials, including high-temperature superconductors, but highly extraordinary within the realm of conventional s p -bonded semiconductor materials. It suggests that exotic quantum matter phases can be realized and engineered on silicon-based materials platforms.

Challenges and solutions for high-volume testing of silicon photonics

NASA Astrophysics Data System (ADS)

Polster, Robert; Dai, Liang Yuan; Oikonomou, Michail; Cheng, Qixiang; Rumley, Sebastien; Bergman, Keren

2018-02-01

The first generation of silicon photonic products is now commercially available. While silicon photonics possesses key economic advantages over classical photonic platforms, it has yet to become a commercial success because these advantages can be fully realized only when high-volume testing of silicon photonic devices is made possible. We discuss the costs, challenges, and solutions of photonic chip testing as reported in the recent research literature. We define and propose three underlying paradigms that should be considered when creating photonic test structures: Design for Fast Coupling, Design for Minimal Taps, and Design for Parallel Testing. We underline that a coherent test methodology must be established prior to the design of test structures, and demonstrate how an optimized methodology dramatically reduces the burden when designing for test, by reducing the needed complexity of test structures.

Silicon carbide, an emerging high temperature semiconductor

NASA Technical Reports Server (NTRS)

Matus, Lawrence G.; Powell, J. Anthony

1991-01-01

In recent years, the aerospace propulsion and space power communities have expressed a growing need for electronic devices that are capable of sustained high temperature operation. Applications for high temperature electronic devices include development instrumentation within engines, engine control, and condition monitoring systems, and power conditioning and control systems for space platforms and satellites. Other earth-based applications include deep-well drilling instrumentation, nuclear reactor instrumentation and control, and automotive sensors. To meet the needs of these applications, the High Temperature Electronics Program at the Lewis Research Center is developing silicon carbide (SiC) as a high temperature semiconductor material. Research is focussed on developing the crystal growth, characterization, and device fabrication technologies necessary to produce a family of silicon carbide electronic devices and integrated sensors. The progress made in developing silicon carbide is presented, and the challenges that lie ahead are discussed.

Nonclassical light sources for silicon photonics

NASA Astrophysics Data System (ADS)

Bajoni, Daniele; Galli, Matteo

2017-09-01

Quantum photonics has recently attracted a lot of attention for its disruptive potential in emerging technologies like quantum cryptography, quantum communication and quantum computing. Driven by the impressive development in nanofabrication technologies and nanoscale engineering, silicon photonics has rapidly become the platform of choice for on-chip integration of high performing photonic devices, now extending their functionalities towards quantum-based applications. Focusing on quantum Information Technology (qIT) as a key application area, we review recent progress in integrated silicon-based sources of nonclassical states of light. We assess the state of the art in this growing field and highlight the challenges that need to be overcome to make quantum photonics a reliable and widespread technology.

Comparing Web and Touch Screen Transaction Log Files

PubMed Central

Huntington, Paul; Williams, Peter

2001-01-01

Background Digital health information is available on a wide variety of platforms including PC-access of the Internet, Wireless Application Protocol phones, CD-ROMs, and touch screen public kiosks. All these platforms record details of user sessions in transaction log files, and there is a growing body of research into the evaluation of this data. However, there is very little research that has examined the problems of comparing the transaction log files of kiosks and the Internet. Objectives To provide a first step towards examining the problems of comparing the transaction log files of kiosks and the Internet. Methods We studied two platforms: touch screen kiosks and a comparable Web site. For both of these platforms, we examined the menu structure (which affects transaction log file data), the log-file structure, and the metrics derived from log-file records. Results We found substantial differences between the generated metrics. Conclusions None of the metrics discussed can be regarded as an effective way of comparing the use of kiosks and Web sites. Two metrics stand out as potentially comparable and valuable: the number of user sessions per hour and user penetration of pages. PMID:11720960

Design of a SIP device cooperation system on OSGi service platforms

NASA Astrophysics Data System (ADS)

Takayama, Youji; Koita, Takahiro; Sato, Kenya

2007-12-01

Home networks feature such various technologies as protocols, specifications, and middleware, including HTTP, UPnP, and Jini. A service platform is required to handle such technologies to enable them to cooperate with different devices. The OSGi service platform, which meets the requirements based on service-oriented architecture, is designed and standardized by OSGi Alliance and consists of two parts: one OSGi Framework and bundles. On the OSGi service platform, APIs are defined as services that can handle these technologies and are implemented in the bundle. By using the OSGi Framework with bundles, various technologies can cooperate with each other. On the other hand, in IP networks, Session Initiation Protocol (SIP) is often used in device cooperation services to resolve an IP address, control a session between two or more devices, and easily exchange the statuses of devices. However, since many existing devices do not correspond to SIP, it cannot be used for device cooperation services. A device that does not correspond to SIP is called an unSIP device. This paper proposes and implements a prototype system that enables unSIP devices to correspond to SIP. For unSIP devices, the proposed system provides device cooperation services with SIP.

Widely-tunable, narrow-linewidth III-V/silicon hybrid external-cavity laser for coherent communication.

PubMed

Guan, Hang; Novack, Ari; Galfsky, Tal; Ma, Yangjin; Fathololoumi, Saeed; Horth, Alexandre; Huynh, Tam N; Roman, Jose; Shi, Ruizhi; Caverley, Michael; Liu, Yang; Baehr-Jones, Thomas; Bergman, Keren; Hochberg, Michael

2018-04-02

We demonstrate a III-V/silicon hybrid external cavity laser with a tuning range larger than 60 nm at the C-band on a silicon-on-insulator platform. A III-V semiconductor gain chip is hybridized into the silicon chip by edge-coupling the silicon chip through a Si 3 N 4 spot size converter. The demonstrated packaging method requires only passive alignment and is thus suitable for high-volume production. The laser has a largest output power of 11 mW with a maximum wall-plug efficiency of 4.2%, tunability of 60 nm (more than covering the C-band), and a side-mode suppression ratio of 55 dB (>46 dB across the C-band). The lowest measured linewidth is 37 kHz (<80 kHz across the C-band), which is the narrowest linewidth using a silicon-based external cavity. In addition, we successfully demonstrate all silicon-photonics-based transmission of 34 Gbaud (272 Gb/s) dual-polarization 16-QAM using our integrated laser and silicon photonic coherent transceiver. The results show no additional penalty compared to commercially available narrow linewidth tunable lasers. To the best of our knowledge, this is the first experimental demonstration of a complete silicon photonic based coherent link. This is also the first experimental demonstration of >250 Gb/s coherent optical transmission using a silicon micro-ring-based tunable laser.

Hybrid graphene/silicon integrated optical isolators with photonic spin–orbit interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Jingwen; Sun, Xiankai, E-mail: xksun@cuhk.edu.hk; Shun Hing Institute of Advanced Engineering, The Chinese University of Hong Kong, Shatin, New Territories

2016-04-11

Optical isolators are an important building block in photonic computation and communication. In traditional optics, isolators are realized with magneto-optical garnets. However, it remains challenging to incorporate such materials on an integrated platform because of the difficulty in material growth and bulky device footprint. Here, we propose an ultracompact integrated isolator by exploiting graphene's magneto-optical property on a silicon-on-insulator platform. The photonic nonreciprocity is achieved because the cyclotrons in graphene experiencing different optical spins exhibit different responses to counterpropagating light. Taking advantage of cavity resonance effects, we have numerically optimized a device design, which shows excellent isolation performance with themore » extinction ratio over 45 dB and the insertion loss around 12 dB at a wavelength near 1.55 μm. Featuring graphene's CMOS compatibility and substantially reduced device footprint, our proposal sheds light on monolithic integration of nonreciprocal photonic devices.« less

Nanoscale light–matter interactions in atomic cladding waveguides

PubMed Central

Stern, Liron; Desiatov, Boris; Goykhman, Ilya; Levy, Uriel

2013-01-01

Alkali vapours, such as rubidium, are being used extensively in several important fields of research such as slow and stored light nonlinear optics quantum computation, atomic clocks and magnetometers. Recently, there is a growing effort towards miniaturizing traditional centimetre-size vapour cells. Owing to the significant reduction in device dimensions, light–matter interactions are greatly enhanced, enabling new functionalities due to the low power threshold needed for nonlinear interactions. Here, taking advantage of the mature platform of silicon photonics, we construct an efficient and flexible platform for tailored light–vapour interactions on a chip. Specifically, we demonstrate light–matter interactions in an atomic cladding waveguide, consisting of a silicon nitride nano-waveguide core with a rubidium vapour cladding. We observe the efficient interaction of the electromagnetic guided mode with the rubidium cladding and show that due to the high confinement of the optical mode, the rubidium absorption saturates at powers in the nanowatt regime. PMID:23462991

Plasmonic nanofocusing of light in an integrated silicon photonics platform.

PubMed

Desiatov, Boris; Goykhman, Ilya; Levy, Uriel

2011-07-04

The capability to focus electromagnetic energy at the nanoscale plays an important role in nanoscinece and nanotechnology. It allows enhancing light matter interactions at the nanoscale with applications related to nonlinear optics, light emission and light detection. It may also be used for enhancing resolution in microscopy, lithography and optical storage systems. Hereby we propose and experimentally demonstrate the nanoscale focusing of surface plasmons by constructing an integrated plasmonic/photonic on chip nanofocusing device in silicon platform. The device was tested directly by measuring the optical intensity along it using a near-field microscope. We found an order of magnitude enhancement of the intensity at the tip's apex. The spot size is estimated to be 50 nm. The demonstrated device may be used as a building block for "lab on a chip" systems and for enhancing light matter interactions at the apex of the tip.

Experimental realization of Bloch oscillations in a parity-time synthetic silicon photonic lattice

PubMed Central

Xu, Ye-Long; Fegadolli, William S.; Gan, Lin; Lu, Ming-Hui; Liu, Xiao-Ping; Li, Zhi-Yuan; Scherer, Axel; Chen, Yan-Feng

2016-01-01

As an important electron transportation phenomenon, Bloch oscillations have been extensively studied in condensed matter. Due to the similarity in wave properties between electrons and other quantum particles, Bloch oscillations have been observed in atom lattices, photonic lattices, and so on. One of the many distinct advantages for choosing these systems over the regular electronic systems is the versatility in engineering artificial potentials. Here by utilizing dissipative elements in a CMOS-compatible photonic platform to create a periodic complex potential and by exploiting the emerging concept of parity-time synthetic photonics, we experimentally realize spatial Bloch oscillations in a non-Hermitian photonic system on a chip level. Our demonstration may have significant impact in the field of quantum simulation by following the recent trend of moving complicated table-top quantum optics experiments onto the fully integrated CMOS-compatible silicon platform. PMID:27095533

Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns

DOE Office of Scientific and Technical Information (OSTI.GOV)

Premnath, Priyatha, E-mail: priyatha.premnath@ryerson.ca; Tavangar, Amirhossein, E-mail: atavanga@ryerson.ca; Tan, Bo, E-mail: tanbo@ryerson.ca

2015-09-10

Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approachmore » to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing direction. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell-adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety of biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that selectively repel cancer cells while favoring the adhesion of normal cells. - Highlights: • Si platforms with cytophobic/philic patterns were developed to program cell growth. • Both nanotopography and chemistry contributed to the cytophobic property. • Cytophobic zones efficiently repel and drive HeLa cells to migrate to adhesive sites. • The approach enables cell patterning, directionality, channelling, and trapping. • This approach paves the way for developing anti-cancer platforms.« less

Characterization of Ag-porous silicon nanostructured layer formed by an electrochemical etching of p-type silicon surface for bio-application

NASA Astrophysics Data System (ADS)

Naddaf, M.; Al-Mariri, A.; Haj-Mhmoud, N.

2017-06-01

Nanostructured layers composed of silver-porous silicon (Ag-PS) have been formed by an electrochemical etching of p-type (1 1 1) silicon substrate in a AgNO3:HF:C2H5OH solution at different etching times (10 min-30 min). Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) results reveal that the produced layers consist of Ag dendrites and a silicon-rich porous structure. The nanostructuring nature of the layer has been confirmed by spatial micro-Raman scattering and x-ray diffraction techniques. The Ag dendrites exhibit a surface-enhanced Raman scattering (SERS) spectrum, while the porous structure shows a typical PS Raman spectrum. Upon increasing the etching time, the average size of silicon nanocrystallite in the PS network decreases, while the average size of Ag nanocrystals is slightly affected. In addition, the immobilization of prokaryote Salmonella typhimurium DNA via physical adsorption onto the Ag-PS layer has been performed to demonstrate its efficiency as a platform for detection of biological molecules using SERS.

The integration of InGaP LEDs with CMOS on 200 mm silicon wafers

NASA Astrophysics Data System (ADS)

Wang, Bing; Lee, Kwang Hong; Wang, Cong; Wang, Yue; Made, Riko I.; Sasangka, Wardhana Aji; Nguyen, Viet Cuong; Lee, Kenneth Eng Kian; Tan, Chuan Seng; Yoon, Soon Fatt; Fitzgerald, Eugene A.; Michel, Jurgen

2017-02-01

The integration of photonics and electronics on a converged silicon CMOS platform is a long pursuit goal for both academe and industry. We have been developing technologies that can integrate III-V compound semiconductors and CMOS circuits on 200 mm silicon wafers. As an example we present our work on the integration of InGaP light-emitting diodes (LEDs) with CMOS. The InGaP LEDs were epitaxially grown on high-quality GaAs and Ge buffers on 200 mm (100) silicon wafers in a MOCVD reactor. Strain engineering was applied to control the wafer bow that is induced by the mismatch of coefficients of thermal expansion between III-V films and silicon substrate. Wafer bonding was used to transfer the foundry-made silicon CMOS wafers to the InGaP LED wafers. Process trenches were opened on the CMOS layer to expose the underneath III-V device layers for LED processing. We show the issues encountered in the 200 mm processing and the methods we have been developing to overcome the problems.

5 × 5 cm2 silicon photonic crystal slabs on glass and plastic foil exhibiting broadband absorption and high-intensity near-fields

PubMed Central

Becker, C.; Wyss, P.; Eisenhauer, D.; Probst, J.; Preidel, V.; Hammerschmidt, M.; Burger, S.

2014-01-01

Crystalline silicon photonic crystal slabs are widely used in various photonics applications. So far, the commercial success of such structures is still limited owing to the lack of cost-effective fabrication processes enabling large nanopatterned areas (≫ 1 cm2). We present a simple method for producing crystalline silicon nanohole arrays of up to 5 × 5 cm2 size with lattice pitches between 600 and 1000 nm on glass and flexible plastic substrates. Exclusively up-scalable, fast fabrication processes are applied such as nanoimprint-lithography and silicon evaporation. The broadband light trapping efficiency of the arrays is among the best values reported for large-area experimental crystalline silicon nanostructures. Further, measured photonic crystal resonance modes are in good accordance with light scattering simulations predicting strong near-field intensity enhancements greater than 500. Hence, the large-area silicon nanohole arrays might become a promising platform for ultrathin solar cells on lightweight substrates, high-sensitive optical biosensors, and nonlinear optics. PMID:25073935

Single-chip photonic transceiver based on bulk-silicon, as a chip-level photonic I/O platform for optical interconnects.

PubMed

Kim, Gyungock; Park, Hyundai; Joo, Jiho; Jang, Ki-Seok; Kwack, Myung-Joon; Kim, Sanghoon; Kim, In Gyoo; Oh, Jin Hyuk; Kim, Sun Ae; Park, Jaegyu; Kim, Sanggi

2015-06-10

When silicon photonic integrated circuits (PICs), defined for transmitting and receiving optical data, are successfully monolithic-integrated into major silicon electronic chips as chip-level optical I/Os (inputs/outputs), it will bring innovative changes in data computing and communications. Here, we propose new photonic integration scheme, a single-chip optical transceiver based on a monolithic-integrated vertical photonic I/O device set including light source on bulk-silicon. This scheme can solve the major issues which impede practical implementation of silicon-based chip-level optical interconnects. We demonstrated a prototype of a single-chip photonic transceiver with monolithic-integrated vertical-illumination type Ge-on-Si photodetectors and VCSELs-on-Si on the same bulk-silicon substrate operating up to 50 Gb/s and 20 Gb/s, respectively. The prototype realized 20 Gb/s low-power chip-level optical interconnects for λ ~ 850 nm between fabricated chips. This approach can have a significant impact on practical electronic-photonic integration in high performance computers (HPC), cpu-memory interface, hybrid memory cube, and LAN, SAN, data center and network applications.

Recent developments using TowerJazz SiGe BiCMOS platform for mmWave and THz applications

NASA Astrophysics Data System (ADS)

Kar-Roy, Arjun; Howard, David; Preisler, Edward J.; Racanelli, Marco

2013-05-01

In this paper, we report on the highest speed 240GHz/340GHz FT/FMAX NPN which is now available for product designs in the SBC18H4 process variant of TowerJazz's mature 0.18μm SBC18 silicon germanium (SiGe) BiCMOS technology platform. NFMIN of ~2dB at 50GHz has been obtained with these NPNs. We also describe the integration of earlier generation NPNs with FT/FMAX of 240GHz/280GHz into SBC13H3, a 0.13μm SiGe BiCMOS technology platform. Next, we detail the integration of the deep silicon via (DSV), through silicon via (TSV), high-resistivity substrate, sub-field stitching and hybrid-stitching capability into the 0.18μm SBC18 technology platform to enable higher performance and highly integrated product designs. The integration of SBC18H3 into a thick-film SOI substrate, with essentially unchanged FT and FMAX, is also described. We also report on recent circuit demonstrations using the SBC18H3 platform: (1) a 4-element phased-array 70-100GHz broadband transmit and receive chip with flat saturated power greater than 5dBm and conversion gain of 33dB; (2) a fully integrated W-band 9-element phase-controllable array with responsivity of 800MV/W and receiver NETD is 0.45K with 20ms integration time; (3) a 16-element 4x4 phased-array transmitter with scanning in both the E- and H-planes with maximum EIRP of 23-25 dBm at 100-110GHz; (4) a power efficient 200GHz VCO with -7.25dBm output power and tuning range of 3.5%; and (5) a 320GHz 16-element imaging receiver array with responsivity of 18KV/W at 315GHz, a 3dB bandwidth of 25GHz and a low NEP of 34pW/Hz1/2. Wafer-scale large-die implementation of the phased-arrays and mmWave imagers using stitching in TowerJazz SBC18 process are also discussed.

Unconference session at the IAU General Assembly 2015

NASA Astrophysics Data System (ADS)

Nava, Tibisay Sankatsing; Venugopal, Ramasamy; Verdolini, Silvia

2016-10-01

The Astronomy For Development Focus Meeting 20 at the IAU General Assembly encompassed an `Unconference' session as part of the proceedings. Unstructured conferences, with their potential to unleash innovative ideas, are gaining traction in various conferences and symposia. Astronomy For Development is a field that is applicable to the entire Astronomy community (and even beyond) and hence an unconference inviting ideas and fostering frank dialogue is very pertinent. Officially one of the final sessions of the the 2015 General Assembly, the unconference session was intended to provide a balanced platform for a diverse set of participants and act as an informal setting to promote open discussion on topics of relevance to Astronomy for Development.

Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

PubMed Central

Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

2013-01-01

Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10–40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage. PMID:24145684

Surface engineered porous silicon for stable, high performance electrochemical supercapacitors.

PubMed

Oakes, Landon; Westover, Andrew; Mares, Jeremy W; Chatterjee, Shahana; Erwin, William R; Bardhan, Rizia; Weiss, Sharon M; Pint, Cary L

2013-10-22

Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10-40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage.

Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

NASA Astrophysics Data System (ADS)

Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

2013-10-01

Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10-40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage.

A silicon central pattern generator controls locomotion in vivo.

PubMed

Vogelstein, R J; Tenore, F; Guevremont, L; Etienne-Cummings, R; Mushahwar, V K

2008-09-01

We present a neuromorphic silicon chip that emulates the activity of the biological spinal central pattern generator (CPG) and creates locomotor patterns to support walking. The chip implements ten integrate-and-fire silicon neurons and 190 programmable digital-to-analog converters that act as synapses. This architecture allows for each neuron to make synaptic connections to any of the other neurons as well as to any of eight external input signals and one tonic bias input. The chip's functionality is confirmed by a series of experiments in which it controls the motor output of a paralyzed animal in real-time and enables it to walk along a three-meter platform. The walking is controlled under closed-loop conditions with the aide of sensory feedback that is recorded from the animal's legs and fed into the silicon CPG. Although we and others have previously described biomimetic silicon locomotor control systems for robots, this is the first demonstration of a neuromorphic device that can replace some functions of the central nervous system in vivo.

Waveguide based compact silicon Schottky photodetector with enhanced responsivity in the telecom spectral band.

PubMed

Goykhman, Ilya; Desiatov, Boris; Khurgin, Jacob; Shappir, Joseph; Levy, Uriel

2012-12-17

We experimentally demonstrate an on-chip compact and simple to fabricate silicon Schottky photodetector for telecom wavelengths operating on the basis of internal photoemission process. The device is realized using CMOS compatible approach of local-oxidation of silicon, which enables the realization of the photodetector and low-loss bus photonic waveguide at the same fabrication step. The photodetector demonstrates enhanced internal responsivity of 12.5mA/W for operation wavelength of 1.55µm corresponding to an internal quantum efficiency of 1%, about two orders of magnitude higher than our previously demonstrated results [22]. We attribute this improved detection efficiency to the presence of surface roughness at the boundary between the materials forming the Schottky contact. The combination of enhanced quantum efficiency together with a simple fabrication process provides a promising platform for the realization of all silicon photodetectors and their integration with other nanophotonic and nanoplasmonic structures towards the construction of monolithic silicon opto-electronic circuitry on-chip.

III–V quantum light source and cavity-QED on Silicon

PubMed Central

Luxmoore, I. J.; Toro, R.; Pozo-Zamudio, O. Del; Wasley, N. A.; Chekhovich, E. A.; Sanchez, A. M.; Beanland, R.; Fox, A. M.; Skolnick, M. S.; Liu, H. Y.; Tartakovskii, A. I.

2013-01-01

Non-classical light sources offer a myriad of possibilities in both fundamental science and commercial applications. Single photons are the most robust carriers of quantum information and can be exploited for linear optics quantum information processing. Scale-up requires miniaturisation of the waveguide circuit and multiple single photon sources. Silicon photonics, driven by the incentive of optical interconnects is a highly promising platform for the passive optical components, but integrated light sources are limited by silicon's indirect band-gap. III–V semiconductor quantum-dots, on the other hand, are proven quantum emitters. Here we demonstrate single-photon emission from quantum-dots coupled to photonic crystal nanocavities fabricated from III–V material grown directly on silicon substrates. The high quality of the III–V material and photonic structures is emphasized by observation of the strong-coupling regime. This work opens-up the advantages of silicon photonics to the integration and scale-up of solid-state quantum optical systems. PMID:23393621

Hybrid Integration of Solid-State Quantum Emitters on a Silicon Photonic Chip.

PubMed

Kim, Je-Hyung; Aghaeimeibodi, Shahriar; Richardson, Christopher J K; Leavitt, Richard P; Englund, Dirk; Waks, Edo

2017-12-13

Scalable quantum photonic systems require efficient single photon sources coupled to integrated photonic devices. Solid-state quantum emitters can generate single photons with high efficiency, while silicon photonic circuits can manipulate them in an integrated device structure. Combining these two material platforms could, therefore, significantly increase the complexity of integrated quantum photonic devices. Here, we demonstrate hybrid integration of solid-state quantum emitters to a silicon photonic device. We develop a pick-and-place technique that can position epitaxially grown InAs/InP quantum dots emitting at telecom wavelengths on a silicon photonic chip deterministically with nanoscale precision. We employ an adiabatic tapering approach to transfer the emission from the quantum dots to the waveguide with high efficiency. We also incorporate an on-chip silicon-photonic beamsplitter to perform a Hanbury-Brown and Twiss measurement. Our approach could enable integration of precharacterized III-V quantum photonic devices into large-scale photonic structures to enable complex devices composed of many emitters and photons.

Surface normal coupling to multiple-slot and cover-slotted silicon nanocrystalline waveguides and ring resonators

NASA Astrophysics Data System (ADS)

Covey, John; Chen, Ray T.

2014-03-01

Grating couplers are ideal for coupling into the tightly confined propagation modes of semiconductor waveguides. In addition, nonlinear optics has benefited from the sub-diffraction limit confinement of horizontal slot waveguides. By combining these two advancements, slot-based nonlinear optics with mode areas less than 0.02 μm2 can become as routine as twisting fiber connectors together. Surface normal fiber alignment to a chip is also highly desirable from time, cost, and manufacturing considerations. To meet these considerable design challenges, a custom genetic algorithm is created which, starting from purely random designs, creates a unique four stage grating coupler for two novel horizontal slot waveguide platforms. For horizontal multiple-slot waveguides filled with silicon nanocrystal, a theoretical fiber-towaveguide coupling efficiency of 68% is obtained. For thin silicon waveguides clad with optically active silicon nanocrystal, known as cover-slot waveguides, a theoretical fiber-to-waveguide coupling efficiency of 47% is obtained, and 1 dB and 3 dB theoretical bandwidths of 70 nm and 150 nm are obtained, respectively. Both waveguide platforms are fabricated from scratch, and their respective on-chip grating couplers are experimentally measured from a standard single mode fiber array that is mounted surface normally. The horizontal multiple-slot grating coupler achieved an experimental 60% coupling efficiency, and the horizontal cover-slot grating coupler achieved an experimental 38.7% coupling efficiency, with an extrapolated 1 dB bandwidth of 66 nm. This report demonstrates the promise of genetic algorithm-based design by reducing to practice the first large bandwidth vertical grating coupler to a novel silicon nanocrystal horizontal cover-slot waveguide.

Hardness assurance testing and radiation hardening by design techniques for silicon-germanium heterojunction bipolar transistors and digital logic circuits

NASA Astrophysics Data System (ADS)

Sutton, Akil K.

Hydrocarbon exploration, global navigation satellite systems, computed tomography, and aircraft avionics are just a few examples of applications that require system operation at an ambient temperature, pressure, or radiation level outside the range covered by military specifications. The electronics employed in these applications are known as "extreme environment electronics." On account of the increased cost resulting from both process modifications and the use of exotic substrate materials, only a handful of semiconductor foundries have specialized in the production of extreme environment electronics. Protection of these electronic systems in an extreme environment may be attained by encapsulating sensitive circuits in a controlled environment, which provides isolation from the hostile ambient, often at a significant cost and performance penalty. In a significant departure from this traditional approach, system designers have begun to use commercial off-the-shelf technology platforms with built in mitigation techniques for extreme environment applications. Such an approach simultaneously leverages the state of the art in technology performance with significant savings in project cost. Silicon-germanium is one such commercial technology platform that demonstrates potential for deployment into extreme environment applications as a result of its excellent performance at cryogenic temperatures, remarkable tolerance to radiation-induced degradation, and monolithic integration with silicon-based manufacturing. In this dissertation the radiation response of silicon-germanium technology is investigated, and novel transistor-level layout-based techniques are implemented to improve the radiation tolerance of HBT digital logic.

Optimized optical devices for edge-coupling-enabled silicon photonics platform

NASA Astrophysics Data System (ADS)

Png, Ching Eng; Ang, Thomas Y. L.; Ong, Jun Rong; Lim, Soon Thor; Sahin, Ezgi; Chen, G. F. R.; Tan, D. T. H.; Guo, Tina X.; Wang, Hong

2018-02-01

We present a library of high-performance passive and active silicon photonic devices at the C-band that is specifically designed and optimized for edge-coupling-enabled silicon photonics platform. These devices meet the broadband (100 nm), low-loss (< 2dB per device), high speed (>= 25 Gb/s), and polarization diversity requirements (TE and TM polarization extinction ratio <= 25 dB) for optical communication applications. Ultra-low loss edge couplers, broadband directional couplers, high-extinction ratio polarization beam splitters (PBSs), and high-speed modulators are some of the devices within our library. In particular, we have designed and fabricated inverse taper fiber-to-waveguide edge couplers of tip widths ranging from 120 nm to 200 nm, and we obtained a low coupling loss of 1.80+/-0.28 dB for 160 nm tip width. To achieve polarization diversity operation for inverse tapers, we have experimentally realized different designs of polarization beam splitters (PBS). Our optimized PBS has a measured extinction ratio of <= 25 dB for both the quasiTE modes, and quasi-TM modes. Additionally, a broadband (100 nm) directional coupler with a 50/50 power splitting ratio was experimentally realized on a small footprint of 20×3 μm2 . Last but not least, high-speed silicon modulators with a range of carrier doping concentrations and offset of the PN junction can be used to optimise the modulation efficiency, and insertion losses for operation at 25 GHz.

A CMOS enhanced solid-state nanopore based single molecule detection platform.

PubMed

Chen, Chinhsuan; Yemenicioglu, Sukru; Uddin, Ashfaque; Corgliano, Ellie; Theogarajan, Luke

2013-01-01

Solid-state nanopores have emerged as a single molecule label-free electronic detection platform. Existing transimpedance stages used to measure ionic current nanopores suffer from dynamic range limitations resulting from steady-state baseline currents. We propose a digitally-assisted baseline cancellation CMOS platform that circumvents this issue. Since baseline cancellation is a form of auto-zeroing, the 1/f noise of the system is also reduced. Our proposed design can tolerate a steady state baseline current of 10µA and has a usable bandwidth of 750kHz. Quantitative DNA translocation experiments on 5kbp DNA was performed using a 5nm silicon nitride pore using both the CMOS platform and a commercial system. Comparison of event-count histograms show that the CMOS platform clearly outperforms the commercial system, allowing for unambiguous interpretation of the data.

International Topical Workshop on Advances in Silicon-Based Polymer Science (2nd) Held in Makaha, Oahu, Hawaii on December 16-20, 1990

DTIC Science & Technology

1990-12-20

Hochstrasser, 1:30 Break/poster session 1 University of Pennsylvania :00 OS1- 3 Synthesis and Properties of Liquid Crystalline Polysiloxanes, 9:00 OS5- 2 Excited...MONDAY P.M. - FROM 1-D TO 3 -D SILOXSANE$ ... ..10.00. OS5-4 Comparison of Radical Anions and Cations of Polygermane Session 2 : Chairman - Geoffrey...Technology W.0O 056- 3 Thermal Sensitivity of Hydropolysilanes, T. M. Hsu and S. P. SAWAN, University of Lowell PS2- 2 T. M. Hsu, SAMUEL P. SAWAN, University of

Wideband nonlinear spectral broadening in ultra-short ultra - silicon rich nitride waveguides

PubMed Central

Choi, Ju Won; Chen, George F. R.; Ng, D. K. T.; Ooi, Kelvin J. A.; Tan, Dawn T. H.

2016-01-01

CMOS-compatible nonlinear optics platforms with high Kerr nonlinearity facilitate the generation of broadband spectra based on self-phase modulation. Our ultra – silicon rich nitride (USRN) platform is designed to have a large nonlinear refractive index and low nonlinear losses at 1.55 μm for the facilitation of wideband spectral broadening. We investigate the ultrafast spectral characteristics of USRN waveguides with 1-mm-length, which have high nonlinear parameters (γ ∼ 550 W−1/m) and anomalous dispersion at 1.55 μm wavelength of input light. USRN add-drop ring resonators broaden output spectra by a factor of 2 compared with the bandwidth of input fs laser with the highest quality factors of 11000 and 15000. Two – fold self phase modulation induced spectral broadening is observed using waveguides only 430 μm in length, whereas a quadrupling of the output bandwidth is observed with USRN waveguides with a 1-mm-length. A broadening factor of around 3 per 1 mm length is achieved in the USRN waveguides, a value which is comparatively larger than many other CMOS-compatible platforms. PMID:27272558

Toward a Platform for Rural America. Report of the National Conference on Rural America (1st, Washington, D.C., April 14-17, 1975).

ERIC Educational Resources Information Center

Rural Housing Alliance, Washington, DC.

A distillation of hundreds of speeches, working papers, panel sessions, informal discussions, and formal resolutions, this report is derived from the First National Conference on Rural America (April 1975) and reflects emergence of a rural political platform. Attended by approximately 1,500 people from 49 States, Puerto Rico, and Canada, the…

Evaluation of a Smartphone Platform as a Wireless Interface Between Tongue Drive System and Electric-Powered Wheelchairs

PubMed Central

Kim, Jeonghee; Huo, Xueliang; Minocha, Julia; Holbrook, Jaimee; Laumann, Anne; Ghovanloo, Maysam

2013-01-01

Tongue drive system (TDS) is a new wireless assistive technology (AT) for the mobility impaired population. It provides users with the ability to drive powered wheelchairs (PWC) and access computers using their unconstrained tongue motion. Migration of the TDS processing unit and user interface platform from a bulky personal computer to a smartphone (iPhone) has significantly facilitated its usage by turning it into a true wireless and wearable AT. After implementation of the necessary interfacing hardware and software to allow the smartphone to act as a bridge between the TDS and PWC, the wheelchair navigation performance and associated learning was evaluated in nine able-bodied subjects in five sessions over a 5-week period. Subjects wore magnetic tongue studs over the duration of the study and drove the PWC in an obstacle course with their tongue using three different navigation strategies; namely unlatched, latched, and semiproportional. Qualitative aspects of using the TDS–iPhone–PWC interface were also evaluated via a five-point Likert scale questionnaire. Subjects showed more than 20% improvement in the overall completion time between the first and second sessions, and maintained a modest improvement of ~9% per session over the following three sessions. PMID:22531737

Method of making gold thiolate and photochemically functionalized microcantilevers

DOEpatents

Boiadjiev, Vassil I [Knoxville, TN; Brown, Gilbert M [Knoxville, TN; Pinnaduwage, Lal A [Knoxville, TN; Thundat, Thomas G [Knoxville, TN; Bonnesen, Peter V [Knoxville, TN; Goretzki, Gudrun [Nottingham, GB

2009-08-25

Highly sensitive sensor platforms for the detection of specific reagents, such as chromate, gasoline and biological species, using microcantilevers and other microelectromechanical systems (MEMS) whose surfaces have been modified with photochemically attached organic monolayers, such as self-assembled monolayers (SAM), or gold-thiol surface linkage are taught. The microcantilever sensors use photochemical hydrosilylation to modify silicon surfaces and gold-thiol chemistry to modify metallic surfaces thereby enabling individual microcantilevers in multicantilever array chips to be modified separately. Terminal vinyl substituted hydrocarbons with a variety of molecular recognition sites can be attached to the surface of silicon via the photochemical hydrosilylation process. By focusing the activating UV light sequentially on selected silicon or silicon nitride hydrogen terminated surfaces and soaking or spotting selected metallic surfaces with organic thiols, sulfides, or disulfides, the microcantilevers are functionalized. The device and photochemical method are intended to be integrated into systems for detecting specific agents including chromate groundwater contamination, gasoline, and biological species.

A review of molecular beam epitaxy of ferroelectric BaTiO3 films on Si, Ge and GaAs substrates and their applications

PubMed Central

Mazet, Lucie; Yang, Sang Mo; Kalinin, Sergei V; Schamm-Chardon, Sylvie; Dubourdieu, Catherine

2015-01-01

SrTiO3 epitaxial growth by molecular beam epitaxy (MBE) on silicon has opened up the route to the monolithic integration of various complex oxides on the complementary metal-oxide–semiconductor silicon platform. Among functional oxides, ferroelectric perovskite oxides offer promising perspectives to improve or add functionalities on-chip. We review the growth by MBE of the ferroelectric compound BaTiO3 on silicon (Si), germanium (Ge) and gallium arsenide (GaAs) and we discuss the film properties in terms of crystalline structure, microstructure and ferroelectricity. Finally, we review the last developments in two areas of interest for the applications of BaTiO3 films on silicon, namely integrated photonics, which benefits from the large Pockels effect of BaTiO3, and low power logic devices, which may benefit from the negative capacitance of the ferroelectric. PMID:27877816

Integrated amorphous silicon-aluminum long-range surface plasmon polariton (LR-SPP) waveguides

NASA Astrophysics Data System (ADS)

Sturlesi, Boaz; Grajower, Meir; Mazurski, Noa; Levy, Uriel

2018-03-01

We demonstrate the design, fabrication, and experimental characterization of a long range surface plasmon polariton waveguide that is compatible with complementary metal-oxide semiconductor backend technology. The structure consists of a thin aluminum strip embedded in amorphous silicon. This configuration offers a symmetric environment in which surface plasmon polariton modes undergo minimal loss. Furthermore, the plasmonic mode profile matches the modes of the dielectric (amorphous silicon) waveguide, thus allowing efficient coupling between silicon photonics and plasmonic platforms. The propagation length of the plasmonic waveguide was measured to be about 27 μm at the telecom wavelength around 1550 nm, in good agreement with numerical simulations. As such, the waveguide features both tight mode confinement and decent propagation length. On top of its photonic properties, placing a metal within the structure may also allow for additional functionalities such as photo-detection, thermo-optic tuning, and electro-optic control to be implemented.

Neurite guidance and three-dimensional confinement via compliant semiconductor scaffolds.

PubMed

Cavallo, Francesca; Huang, Yu; Dent, Erik W; Williams, Justin C; Lagally, Max G

2014-12-23

Neurons are often cultured in vitro on a flat, open, and rigid substrate, a platform that does not reflect well the native microenvironment of the brain. To address this concern, we have developed a culturing platform containing arrays of microchannels, formed in a crystalline-silicon nanomembrane (NM) resting on polydimethylsiloxane; this platform will additionally enable active sensing and stimulation at the local scale, via devices fabricated in the silicon. The mechanical properties of the composite Si/compliant substrate nanomaterial approximate those of neural tissue. The microchannels, created in the NM by strain engineering, demonstrate strong guidance of neurite outgrowth. Using plasma techniques, we developed a means to coat just the inside surface of these channels with an adhesion promoter (poly-d-lysine). For NM channels with openings larger than the cross-sectional area of a single axon, strong physical confinement and guidance of axons through the channels are observed. Imaging of axons that grow in channels with openings that approximate the size of an axon suggests that a tight seal exists between the cell membrane and the inner surface of the channel, mimicking a myelin sheath. Such a tight seal of the cell membrane with the channel surface would make this platform an attractive candidate for future neuronal repair. Results of measurements of impedance and photoluminescence of bare NM channels are comparable to those on a flat NM, demonstrating electrical and optical modalities of our platform and suggesting that this scaffold can be expanded for active sensing and monitoring of neuron cellular processes in conditions in which they exist naturally.

TriPleX: a versatile dielectric photonic platform

NASA Astrophysics Data System (ADS)

Wörhoff, Kerstin; Heideman, René G.; Leinse, Arne; Hoekman, Marcel

2015-04-01

Photonic applications based on planar waveguide technology impose stringent requirements on properties such as optical propagation losses, light coupling to optical fibers, integration density, as well as on reliability and reproducibility. The latter is correlated to a high level of control of the refractive index and waveguide geometry. In this paper, we review a versatile dielectric waveguide platform, called TriPleX, which is based on alternating silicon nitride and silicon dioxide films. Fabrication with CMOS-compatible equipment based on low-pressure chemical vapor deposition enables the realization of stable material compositions being a prerequisite to the control of waveguide properties and modal shape. The transparency window of both materials allows for the realization of low-loss waveguides over a wide wavelength range (400 nm-2.35 μm). Propagation losses as low as 5×10-4 dB/cm are reported. Three basic geometries (box shell, double stripe, and filled box) can be distinguished. A specific tapering technology is developed for on-chip, low-loss (<0.1 dB) spotsize convertors, allowing for combining efficient fiber to chip coupling with high-contrast waveguides required for increased functional complexity as well as for hybrid integration with other photonic platforms such as InP and SOI. The functionality of the TriPleX platform is captured by verified basic building blocks. The corresponding library and associated design kit is available for multi-project wafer (MPW) runs. Several applications of this platform technology in communications, biomedicine, sensing, as well as a few special fields of photonics are treated in more detail.

PtSi gimbal-based FLIR for airborne applications

NASA Astrophysics Data System (ADS)

Wallace, Joseph; Ornstein, Itzhak; Nezri, M.; Fryd, Y.; Bloomberg, Steve; Beem, S.; Bibi, B.; Hem, S.; Perna, Steve N.; Tower, John R.; Lang, Frank B.; Villani, Thomas S.; McCarthy, D. R.; Stabile, Paul J.

1997-08-01

A new gimbal-based, FLIR camera for several types of airborne platforms has been developed. The FLIR is based on a PtSi on silicon technology: developed for high volume and minimum cost. The gimbal scans an area of 360 degrees in azimuth and an elevation range of plus 15 degrees to minus 105 degrees. It is stabilized to 25 (mu) Rad-rms. A combination of uniformity correction, defect substitution, and compact optics results in a long range, low cost FLIR for all low-speed airborne platforms.

SOI layout decomposition for double patterning lithography on high-performance computer platforms

NASA Astrophysics Data System (ADS)

Verstov, Vladimir; Zinchenko, Lyudmila; Makarchuk, Vladimir

2014-12-01

In the paper silicon on insulator layout decomposition algorithms for the double patterning lithography on high performance computing platforms are discussed. Our approach is based on the use of a contradiction graph and a modified concurrent breadth-first search algorithm. We evaluate our technique on 45 nm Nangate Open Cell Library including non-Manhattan geometry. Experimental results show that our soft computing algorithms decompose layout successfully and a minimal distance between polygons in layout is increased.

The Effect of Postmastectomy Radiation Therapy on Breast Implants: Material Analysis on Silicone and Polyurethane Prosthesis.

PubMed

Lo Torto, Federico; Relucenti, Michela; Familiari, Giuseppe; Vaia, Nicola; Casella, Donato; Matassa, Roberto; Miglietta, Selenia; Marinozzi, Franco; Bini, Fabiano; Fratoddi, Ilaria; Sciubba, Fabio; Cassese, Raffaele; Tombolini, Vincenzo; Ribuffo, Diego

2018-05-17

The pathogenic mechanism underlying capsular contracture is still unknown. It is certainly a multifactorial process, resulting from human body reaction, biofilm activation, bacteremic seeding, or silicone exposure. The scope of the present article is to investigate the effect of hypofractionated radiotherapy protocol (2.66 Gy × 16 sessions) both on silicone and polyurethane breast implants. Silicone implants and polyurethane underwent irradiation according to a hypofractionated radiotherapy protocol for the treatment of breast cancer. After irradiation implant shells underwent mechanical, chemical, and microstructural evaluation by means of tensile testing, infrared spectra in attenuated total reflectance mode, nuclear magnetic resonance, and field emission scanning electron microscopy. At superficial analysis, irradiated silicone samples show several visible secondary and tertiary blebs. Polyurethane implants showed an open cell structure, which closely resembles a sponge. Morphological observation of struts from treated polyurethane sample shows a more compact structure, with significantly shorter and thicker struts compared with untreated sample. The infrared spectra in attenuated total reflectance mode spectra of irradiated and control samples were compared either for silicon and polyurethane samples. In the case of silicone-based membranes, treated and control specimens showed similar bands, with little differences in the treated one. Nuclear magnetic resonance spectra on the fraction soluble in CDCl3 support these observations. Tensile tests on silicone samples showed a softer behavior of the treated ones. Tensile tests on Polyurethane samples showed no significant differences. Polyurethane implants seem to be more resistant to radiotherapy damage, whereas silicone prosthesis showed more structural, mechanical, and chemical modifications.

Embracing the quantum limit in silicon computing.

PubMed

Morton, John J L; McCamey, Dane R; Eriksson, Mark A; Lyon, Stephen A

2011-11-16

Quantum computers hold the promise of massive performance enhancements across a range of applications, from cryptography and databases to revolutionary scientific simulation tools. Such computers would make use of the same quantum mechanical phenomena that pose limitations on the continued shrinking of conventional information processing devices. Many of the key requirements for quantum computing differ markedly from those of conventional computers. However, silicon, which plays a central part in conventional information processing, has many properties that make it a superb platform around which to build a quantum computer. © 2011 Macmillan Publishers Limited. All rights reserved

Real-time monitoring of surface-initiated atom transfer radical polymerization using silicon photonic microring resonators: implications for combinatorial screening of polymer brush growth conditions.

PubMed

Limpoco, F Ted; Bailey, Ryan C

2011-09-28

We directly monitor in parallel and in real time the temporal profiles of polymer brushes simultaneously grown via multiple ATRP reaction conditions on a single substrate using arrays of silicon photonic microring resonators. In addition to probing relative polymerization rates, we show the ability to evaluate the dynamic properties of the in situ grown polymers. This presents a powerful new platform for studying modified interfaces that may allow for the combinatorial optimization of surface-initiated polymerization conditions.

Initial investigation of SU-8 photopolymer as a material for noninvasive endothelial cell research platforms

NASA Astrophysics Data System (ADS)

Westwood, S.; Gojova, A.; Kuo, B.; Barakat, A. I.; Gray, B. L.

2007-01-01

This paper presents a preliminary investigation in the usage of the micromachining polymer material SU-8 for the noninvasive shape control and functional study of vascular endothelial cells (ECs). We previously demonstrated a silicon and glass modular microinstrument platform that allowed for a wide range of EC functional response studies. However, we expect SU-8 to provide a more versatile fabrication technology and material for microchannel fabrication and instrumentation, since it is capable of achieving high aspect ratio sensor-compatible structures through simple photopatterning. In this paper, SU-8 microchannels were fabricated on glass slides for straightforward optical observation and biological sampling. Channel widths ranged from 50 to 210 µm, length varied from 100 to 2100 µm, with depth fixed at 100 µm. We plated bovine aortic endothelial cells (BAECs) in the microchannels and used image analysis to determine cellular elongation and orientation. Similar to silicon-on-glass microchannels, the cells become more elongated and oriented along the microchannel axis as the width of the microchannel decreases. Initial results indicate cells plate in the microchannels and on the SU-8 surfaces, whereas in a previous silicon microchannel study, cells plated exclusively on the glass bottom surfaces. This finding has implications for SU-8 as a structural material for microchannel instrumentation.

All-optical control of light on a graphene-on-silicon nitride chip using thermo-optic effect.

PubMed

Qiu, Ciyuan; Yang, Yuxing; Li, Chao; Wang, Yifang; Wu, Kan; Chen, Jianping

2017-12-06

All-optical signal processing avoids the conversion between optical signals and electronic signals and thus has the potential to achieve a power efficient photonic system. Micro-scale all-optical devices for light manipulation are the key components in the all-optical signal processing and have been built on the semiconductor platforms (e.g., silicon and III-V semiconductors). However, the two-photon absorption (TPA) effect and the free-carrier absorption (FCA) effect in these platforms deteriorate the power handling and limit the capability to realize complex functions. Instead, silicon nitride (Si 3 N 4 ) provides a possibility to realize all-optical large-scale integrated circuits due to its insulator nature without TPA and FCA. In this work, we investigate the physical dynamics of all-optical control on a graphene-on-Si 3 N 4 chip based on thermo-optic effect. In the experimental demonstration, a switching response time constant of 253.0 ns at a switching energy of ~50 nJ is obtained with a device dimension of 60 μm × 60 μm, corresponding to a figure of merit (FOM) of 3.0 nJ mm. Detailed coupled-mode theory based analysis on the thermo-optic effect of the device has been performed.

Report on the Infinium 450k methylation array analysis workshop: April 20, 2012 UCL, London, UK.

PubMed

Morris, Tiffany; Lowe, Robert

2012-08-01

A new platform for DNA methylome analysis is Illumina's Infinium HumanMethylation450. This technology is an extension of the previous HumanMethylation27 BeadChip and allows the methylation status of 12 samples per chip and 4 to 8 chips (total of 48 to 96 samples) to be assessed simultaneously for more than 480,000 cytosines across the genome. The platform incorporates two different probe types using different assay designs (InfiniumI and InfiniumII). Although this has allowed the assessment of more CpG sites, it has also introduced technical variation between the two probe types, which has complicated the analysis process. Many groups are working on normalization methods and analysis pipelines while many others are struggling to make sense of their new data sets. This motivated the organization of a meeting held at University College London that focused solely on the analysis methods and problems related to this new platform. The meeting was attended by 125 computational and bench scientists from 11 countries. There were 10 speakers, a small poster session and a discussion session.

Hybrid III-V/silicon lasers

NASA Astrophysics Data System (ADS)

Kaspar, P.; Jany, C.; Le Liepvre, A.; Accard, A.; Lamponi, M.; Make, D.; Levaufre, G.; Girard, N.; Lelarge, F.; Shen, A.; Charbonnier, P.; Mallecot, F.; Duan, G.-H.; Gentner, J.-.; Fedeli, J.-M.; Olivier, S.; Descos, A.; Ben Bakir, B.; Messaoudene, S.; Bordel, D.; Malhouitre, S.; Kopp, C.; Menezo, S.

2014-05-01

The lack of potent integrated light emitters is one of the bottlenecks that have so far hindered the silicon photonics platform from revolutionizing the communication market. Photonic circuits with integrated light sources have the potential to address a wide range of applications from short-distance data communication to long-haul optical transmission. Notably, the integration of lasers would allow saving large assembly costs and reduce the footprint of optoelectronic products by combining photonic and microelectronic functionalities on a single chip. Since silicon and germanium-based sources are still in their infancy, hybrid approaches using III-V semiconductor materials are currently pursued by several research laboratories in academia as well as in industry. In this paper we review recent developments of hybrid III-V/silicon lasers and discuss the advantages and drawbacks of several integration schemes. The integration approach followed in our laboratory makes use of wafer-bonded III-V material on structured silicon-on-insulator substrates and is based on adiabatic mode transfers between silicon and III-V waveguides. We will highlight some of the most interesting results from devices such as wavelength-tunable lasers and AWG lasers. The good performance demonstrates that an efficient mode transfer can be achieved between III-V and silicon waveguides and encourages further research efforts in this direction.

Single-chip photonic transceiver based on bulk-silicon, as a chip-level photonic I/O platform for optical interconnects

PubMed Central

Kim, Gyungock; Park, Hyundai; Joo, Jiho; Jang, Ki-Seok; Kwack, Myung-Joon; Kim, Sanghoon; Gyoo Kim, In; Hyuk Oh, Jin; Ae Kim, Sun; Park, Jaegyu; Kim, Sanggi

2015-01-01

When silicon photonic integrated circuits (PICs), defined for transmitting and receiving optical data, are successfully monolithic-integrated into major silicon electronic chips as chip-level optical I/Os (inputs/outputs), it will bring innovative changes in data computing and communications. Here, we propose new photonic integration scheme, a single-chip optical transceiver based on a monolithic-integrated vertical photonic I/O device set including light source on bulk-silicon. This scheme can solve the major issues which impede practical implementation of silicon-based chip-level optical interconnects. We demonstrated a prototype of a single-chip photonic transceiver with monolithic-integrated vertical-illumination type Ge-on-Si photodetectors and VCSELs-on-Si on the same bulk-silicon substrate operating up to 50 Gb/s and 20 Gb/s, respectively. The prototype realized 20 Gb/s low-power chip-level optical interconnects for λ ~ 850 nm between fabricated chips. This approach can have a significant impact on practical electronic-photonic integration in high performance computers (HPC), cpu-memory interface, hybrid memory cube, and LAN, SAN, data center and network applications. PMID:26061463

Photovoltage field-effect transistors

NASA Astrophysics Data System (ADS)

Adinolfi, Valerio; Sargent, Edward H.

2017-02-01

The detection of infrared radiation enables night vision, health monitoring, optical communications and three-dimensional object recognition. Silicon is widely used in modern electronics, but its electronic bandgap prevents the detection of light at wavelengths longer than about 1,100 nanometres. It is therefore of interest to extend the performance of silicon photodetectors into the infrared spectrum, beyond the bandgap of silicon. Here we demonstrate a photovoltage field-effect transistor that uses silicon for charge transport, but is also sensitive to infrared light owing to the use of a quantum dot light absorber. The photovoltage generated at the interface between the silicon and the quantum dot, combined with the high transconductance provided by the silicon device, leads to high gain (more than 104 electrons per photon at 1,500 nanometres), fast time response (less than 10 microseconds) and a widely tunable spectral response. Our photovoltage field-effect transistor has a responsivity that is five orders of magnitude higher at a wavelength of 1,500 nanometres than that of previous infrared-sensitized silicon detectors. The sensitization is achieved using a room-temperature solution process and does not rely on traditional high-temperature epitaxial growth of semiconductors (such as is used for germanium and III-V semiconductors). Our results show that colloidal quantum dots can be used as an efficient platform for silicon-based infrared detection, competitive with state-of-the-art epitaxial semiconductors.

Electrical Double Layer-Induced Ion Surface Accumulation for Ultrasensitive Refractive Index Sensing with Nanostructured Porous Silicon Interferometers.

PubMed

Mariani, Stefano; Strambini, Lucanos Marsilio; Barillaro, Giuseppe

2018-03-23

Herein, we provide the first experimental evidence on the use of electrical double layer (EDL)-induced accumulation of charged ions (using both Na + and K + ions in water as the model) onto a negatively charged nanostructured surface (e.g., thermally growth SiO 2 )-Ion Surface Accumulation, ISA-as a means of improving performance of nanostructured porous silicon (PSi) interferometers for optical refractometric applications. Nanostructured PSi interferometers are very promising optical platforms for refractive index sensing due to PSi huge specific surface (hundreds of m 2 per gram) and low preparation cost (less than $0.01 per 8 in. silicon wafer), though they have shown poor resolution ( R) and detection limit (DL) (on the order of 10 -4 -10 -5 RIU) compared to other plasmonic and photonic platforms ( R and DL on the order of 10 -7 -10 -8 RIU). This can be ascribed to both low sensitivity and high noise floor of PSi interferometers when bulk refractive index variation of the solution infiltrating the nanopores either approaches or is below 10 -4 RIU. Electrical double layer-induced ion surface accumulation (EDL-ISA) on oxidized PSi interferometers allows the interferometer output signal (spectral interferogram) to be impressively amplified at bulk refractive index variation below 10 -4 RIU, increasing, in turn, sensitivity up to 2 orders of magnitude and allowing reliable measurement of refractive index variations to be carried out with both DL and R of 10 -7 RIU. This represents a 250-fold-improvement (at least) with respect to the state-of-the-art literature on PSi refractometers and pushes PSi interferometer performance to that of state-of-the-art ultrasensitive photonics/plasmonics refractive index platforms.

Proceedings of the Flat-Plate Solar Array Project Workshop on Crystal Gowth for High-Efficiency Silicon Solar Cells

NASA Technical Reports Server (NTRS)

Dumas, K. A. (Editor)

1985-01-01

A Workshop on Crystal Growth for High-Efficiency Silicon Solar Cells was held December 3 and 4, 1984, in San Diego, California. The Workshop offered a day and a half of technical presentations and discussions and an afternoon session that involved a panel discussion and general discussion of areas of research that are necessary to the development of materials for high-efficiency solar cells. Topics included the theoretical and experimental aspects of growing high-quality silicon crystals, the effects of growth-process-related defects on photovoltaic devices, and the suitability of various growth technologies as cost-effective processes. Fifteen invited papers were presented, with a discussion period following each presentation. The meeting was organized by the Flat-Plate Solar Array Project of the Jet Propulsion Laboratory. These Proceedings are a record of the presentations and discussions, edited for clarity and continuity.

Effects of macro- versus nanoporous silicon substrates on human aortic endothelial cell behavior

PubMed Central

2014-01-01

Human aortic endothelial cells play a key role in the pathogenesis of atherosclerosis, which is a common, progressive, and multifactorial disease that is the clinical endpoint of an inflammatory process and endothelial dysfunction. Study and development of new therapies against cardiovascular disease must be tested in vitro cell models, prior to be evaluated in vivo. To this aim, new cell culture platforms are developed that allow cells to grow and respond to their environment in a realistic manner. In this work, the cell adhesion and morphology of endothelial cells are investigated on functionalized porous silicon substrates with two different pore size configurations: macroporous and nanoporous silicon. Herein, we modified the surfaces of porous silicon substrates by aminopropyl triethoxysilane, and we studied how different pore geometries induced different cellular response in the cell morphology and adhesion. The cell growth over the surface of porous silicon becomes an attractive field, especially for medical applications. Surface properties of the biomaterial are associated with cell adhesion and as well as, with proliferation, migration and differentiation. PMID:25246859

Quantum cascade lasers grown on silicon.

PubMed

Nguyen-Van, Hoang; Baranov, Alexei N; Loghmari, Zeineb; Cerutti, Laurent; Rodriguez, Jean-Baptiste; Tournet, Julie; Narcy, Gregoire; Boissier, Guilhem; Patriarche, Gilles; Bahriz, Michael; Tournié, Eric; Teissier, Roland

2018-05-08

Technological platforms offering efficient integration of III-V semiconductor lasers with silicon electronics are eagerly awaited by industry. The availability of optoelectronic circuits combining III-V light sources with Si-based photonic and electronic components in a single chip will enable, in particular, the development of ultra-compact spectroscopic systems for mass scale applications. The first circuits of such type were fabricated using heterogeneous integration of semiconductor lasers by bonding the III-V chips onto silicon substrates. Direct epitaxial growth of interband III-V laser diodes on silicon substrates has also been reported, whereas intersubband emitters grown on Si have not yet been demonstrated. We report the first quantum cascade lasers (QCLs) directly grown on a silicon substrate. These InAs/AlSb QCLs grown on Si exhibit high performances, comparable with those of the devices fabricated on their native InAs substrate. The lasers emit near 11 µm, the longest emission wavelength of any laser integrated on Si. Given the wavelength range reachable with InAs/AlSb QCLs, these results open the way to the development of a wide variety of integrated sensors.

Silicone-based composite materials simulate breast tissue to be used as ultrasonography training phantoms.

PubMed

Ustbas, Burcin; Kilic, Deniz; Bozkurt, Ayhan; Aribal, Mustafa Erkin; Akbulut, Ozge

2018-08-01

A silicone-based composite breast phantom is fabricated to be used as an education model in ultrasonography training. A matrix of silicone formulations is tracked to mimic the ultrasonography and tactile response of human breast tissue. The performance of two different additives: (i) silicone oil and (ii) vinyl-terminated poly (dimethylsiloxane) (PDMS) are monitored by a home-made acoustic setup. Through the use of 75 wt% vinyl-terminated PDMS in two-component silicone elastomer mixture, a sound velocity of 1.29 ± 0.09 × 10 3  m/s and an attenuation coefficient of 12.99 ± 0.08 dB/cm-values those match closely to the human breast tissue-are measured with 5 MHz probe. This model can also be used for needle biopsy as well as for self-exam trainings. Herein, we highlight the fabrication of a realistic, durable, accessible, and cost-effective training platform that contains skin layer, inner breast tissue, and tumor masses. Copyright © 2018 Elsevier B.V. All rights reserved.

High speed analog-to-digital conversion with silicon photonics

NASA Astrophysics Data System (ADS)

Holzwarth, C. W.; Amatya, R.; Araghchini, M.; Birge, J.; Byun, H.; Chen, J.; Dahlem, M.; DiLello, N. A.; Gan, F.; Hoyt, J. L.; Ippen, E. P.; Kärtner, F. X.; Khilo, A.; Kim, J.; Kim, M.; Motamedi, A.; Orcutt, J. S.; Park, M.; Perrott, M.; Popovic, M. A.; Ram, R. J.; Smith, H. I.; Zhou, G. R.; Spector, S. J.; Lyszczarz, T. M.; Geis, M. W.; Lennon, D. M.; Yoon, J. U.; Grein, M. E.; Schulein, R. T.; Frolov, S.; Hanjani, A.; Shmulovich, J.

2009-02-01

Sampling rates of high-performance electronic analog-to-digital converters (ADC) are fundamentally limited by the timing jitter of the electronic clock. This limit is overcome in photonic ADC's by taking advantage of the ultra-low timing jitter of femtosecond lasers. We have developed designs and strategies for a photonic ADC that is capable of 40 GSa/s at a resolution of 8 bits. This system requires a femtosecond laser with a repetition rate of 2 GHz and timing jitter less than 20 fs. In addition to a femtosecond laser this system calls for the integration of a number of photonic components including: a broadband modulator, optical filter banks, and photodetectors. Using silicon-on-insulator (SOI) as the platform we have fabricated these individual components. The silicon optical modulator is based on a Mach-Zehnder interferometer architecture and achieves a VπL of 2 Vcm. The filter banks comprise 40 second-order microring-resonator filters with a channel spacing of 80 GHz. For the photodetectors we are exploring ion-bombarded silicon waveguide detectors and germanium films epitaxially grown on silicon utilizing a process that minimizes the defect density.

Recent Advances on Luminescent Enhancement-Based Porous Silicon Biosensors.

PubMed

Jenie, S N Aisyiyah; Plush, Sally E; Voelcker, Nicolas H

2016-10-01

Luminescence-based detection paradigms have key advantages over other optical platforms such as absorbance, reflectance or interferometric based detection. However, autofluorescence, low quantum yield and lack of photostability of the fluorophore or emitting molecule are still performance-limiting factors. Recent research has shown the need for enhanced luminescence-based detection to overcome these drawbacks while at the same time improving the sensitivity, selectivity and reducing the detection limits of optical sensors and biosensors. Nanostructures have been reported to significantly improve the spectral properties of the emitting molecules. These structures offer unique electrical, optic and magnetic properties which may be used to tailor the surrounding electrical field of the emitter. Here, the main principles behind luminescence and luminescence enhancement-based detections are reviewed, with an emphasis on europium complexes as the emitting molecule. An overview of the optical porous silicon microcavity (pSiMC) as a biosensing platform and recent proof-of-concept examples on enhanced luminescence-based detection using pSiMCs are provided and discussed.

A 1 GHz integrated circuit with carbon nanotube interconnects and silicon transistors.

PubMed

Close, Gael F; Yasuda, Shinichi; Paul, Bipul; Fujita, Shinobu; Wong, H-S Philip

2008-02-01

Due to their excellent electrical properties, metallic carbon nanotubes are promising materials for interconnect wires in future integrated circuits. Simulations have shown that the use of metallic carbon nanotube interconnects could yield more energy efficient and faster integrated circuits. The next step is to build an experimental prototype integrated circuit using carbon nanotube interconnects operating at high speed. Here, we report the fabrication of the first stand-alone integrated circuit combining silicon transistors and individual carbon nanotube interconnect wires on the same chip operating above 1 GHz. In addition to setting a milestone by operating above 1 GHz, this prototype is also a tool to investigate carbon nanotubes on a silicon-based platform at high frequencies, paving the way for future multi-GHz nanoelectronics.

[The Moodle platform: A useful tool for training in life support. Analysis of satisfaction questionnaires from students and instructors of the semFYC advanced life support courses].

PubMed

Cordero Torres, Juan Antonio; Caballero Oliver, Antonio

2015-01-01

The aim of this study is to assess the validity and use of a mixed method of training in life support. The use of Moodle to implement an online pre-sessional phase prior to a "classic" classroom phase of teaching in this type of course is the main novelty. Analysis of satisfaction questionnaires of students and instructors of a mixed course in the advanced life support program of SemFYC (ESVAP). Moodle platform. semFYC Virtual Classroom. Students and instructors participating in the semFYC advanced life support program, ESVAP. Qualitative analysis. The majority of students rate as very useful (50%) or useful (45.37%) the existence of an online pre-sessional phase, and consider that it has helped them very much (42.20%) or quite a lot (48.62%) to make the most of the face-to-face sessions. For instructors, they considered that the existence of an online pre-sessional phase was very useful (89%) or useful (11%) for the development of the face-to-face sessions. The analysis of the results concluded that: 1) the students considered a prior non-face to face phase as very useful, and it helped them much/very much in the face to face phase, and 2) the instructors believe that the non-face to face phase had helped them a lot in the presentations and efficiency of the workshops in the face-to-face phase. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

A Photostable Silicon Rhodamine Platform for Optical Voltage Sensing

PubMed Central

Huang, Yi-Lin; Walker, Alison S.; Miller, Evan W.

2015-01-01

This paper describes the design and synthesis of a photostable, far-red to near-infrared (NIR) platform for optical voltage sensing. We developed a new, sulfonated silicon rhodamine fluorophore and integrated it with a phenylenevinylene molecular wire to create a Berkeley Red Sensor of Transmembrane potential, or BeRST 1 (“burst”). BeRST 1 is the first member of a class of farred to NIR voltage sensitive dyes that make use of a photoinduced electron transfer (PeT) trigger for optical interrogation of membrane voltage. We show that BeRST 1 displays bright, membrane-localized fluorescence in living cells, high photostability, and excellent voltage sensitivity in neurons. Depolarization of the plasma membrane results in rapid fluorescence increases (24% ΔF/F per 100 mV). BeRST 1 can be used in conjunction with fluorescent stains for organelles, Ca2+ indicators, and voltage-sensitive fluorescent proteins. In addition, the red-shifted spectral profile of BeRST 1, relative to commonly employed optogenetic actuators like ChannelRhodopsin2 (ChR2), which require blue light, enables optical electrophysiology in neurons. The high speed, sensitivity, photostability and long-wavelength fluorescence profiles of BeRST 1 make it a useful platform for the non-invasive, optical dissection of neuronal activity. PMID:26237573

Advanced Silicon Photonic Device Architectures for Optical Communications: Proposals and Demonstrations

NASA Astrophysics Data System (ADS)

Sacher, Wesley David

Photonic integrated circuits implemented on silicon (Si) hold the potential for densely integrated electro-optic and passive devices manufactured by the high-volume fabrication and sophisticated assembly processes used for complementary metal-oxide-semiconductor (CMOS) electronics. However, high index contrast Si photonics has a number of functional limitations. In this thesis, several devices are proposed, designed, and experimentally demonstrated to overcome challenges in the areas of resonant modulation, waveguide loss, fiber-to-chip coupling, and polarization control. The devices were fabricated using foundry services at IBM and A*STAR Institute of Microelectronics (IME). First, we describe coupling modulated microrings, in which the coupler between a microring and the bus waveguide is modulated. The device circumvents the modulation bandwidth vs. resonator linewidth trade-off of conventional intracavity modulated microrings. We demonstrate a Si coupling modulated microring with a small-signal modulation response free of the parasitic resonator linewidth limitations at frequencies up to about 6x the linewidth. Comparisons of eye diagrams show that coupling modulation achieved data rates > 2x the rate attainable with intracavity modulation. Second, we demonstrate a silicon nitride (Si3N4)-on-Si photonic platform with independent Si3N4 and Si waveguides and taper transitions to couple light between the layers. The platform combines the excellent passive waveguide properties of Si3N4 and the compatibility of Si waveguides with electro-optic devices. Within the platform, we propose and demonstrate dual-level, Si3N 4-on-Si, fiber-to-chip grating couplers that simultaneously have wide bandwidths and high coupling efficiencies. Conventional Si and Si3N 4 grating couplers suffer from a trade-off between bandwidth and coupling efficiency. The dual-level grating coupler achieved a peak coupling efficiency of -1.3 dB and a 1-dB bandwidth of 80 nm, a record for the coupling efficiency-bandwidth product. Finally, we describe polarization rotator-splitters and controllers based on mode conversion between the fundamental transverse magnetic polarized mode and a high order transverse electric polarized mode in vertically asymmetric waveguides. We demonstrate the first polarization rotator-splitters and controllers that are fully compatible with standard active Si photonic platforms and extend the concept to our Si3N4-on-Si photonic platform.

Material platforms for spin-based photonic quantum technologies

NASA Astrophysics Data System (ADS)

Atatüre, Mete; Englund, Dirk; Vamivakas, Nick; Lee, Sang-Yun; Wrachtrup, Joerg

2018-05-01

A central goal in quantum optics and quantum information science is the development of quantum networks to generate entanglement between distributed quantum memories. Experimental progress relies on the quality and efficiency of the light-matter quantum interface connecting the quantum states of photons to internal states of quantum emitters. Quantum emitters in solids, which have properties resembling those of atoms and ions, offer an opportunity for realizing light-matter quantum interfaces in scalable and compact hardware. These quantum emitters require a material platform that enables stable spin and optical properties, as well as a robust manufacturing of quantum photonic circuits. Because no emitter system is yet perfect and different applications may require different properties, several light-matter quantum interfaces are being developed in various platforms. This Review highlights the progress in three leading material platforms: diamond, silicon carbide and atomically thin semiconductors.

Fully suspended slot waveguide platform

NASA Astrophysics Data System (ADS)

Zhou, Wen; Cheng, Zhenzhou; Wu, Xinru; Sun, Xiankai; Tsang, Hon Ki

2018-02-01

A fully suspended slot waveguide (FSSWG) platform, including straight slot waveguides, 90° bends, high-Q racetrack resonators, and strip-to-slot mode converters, is demonstrated for broadband and low-loss operation in the mid-infrared spectral region. The proposed FSSWG platform has inherent merits of a broad spectral range of transparency which is limited only by the absorption of silicon, strong light-analyte interaction, good mechanical stability, and single lithography step fabrication process. By using asymmetric FSSWGs, the propagation loss, bending loss, and intrinsic optical Q factor are demonstrated to be 2.8 dB/cm, 0.15 dB/90°, and 12 600, respectively. The average conversion efficiency of a mode converter is 95.4% over a bandwidth of 170 nm and 97.0% at 2231 nm. The FSSWG platform would be promising for a long-range and cavity-enhanced light-analyte interaction.

Integrated programmable photonic filter on the silicon-on-insulator platform.

PubMed

Liao, Shasha; Ding, Yunhong; Peucheret, Christophe; Yang, Ting; Dong, Jianji; Zhang, Xinliang

2014-12-29

We propose and demonstrate a silicon-on-insulator (SOI) on-chip programmable filter based on a four-tap finite impulse response structure. The photonic filter is programmable thanks to amplitude and phase modulation of each tap controlled by thermal heaters. We further demonstrate the tunability of the filter central wavelength, bandwidth and variable passband shape. The tuning range of the central wavelength is at least 42% of the free spectral range. The bandwidth tuning range is at least half of the free spectral range. Our scheme has distinct advantages of compactness, capability for integrating with electronics.

Hybrid III/V silicon photonic source with integrated 1D free-space beam steering.

PubMed

Doylend, J K; Heck, M J R; Bovington, J T; Peters, J D; Davenport, M L; Coldren, L A; Bowers, J E

2012-10-15

A chip-scale optical source with integrated beam steering is demonstrated. The chip was fabricated using the hybrid silicon platform and incorporates an on-chip laser, waveguide splitter, amplifiers, phase modulators, and surface gratings to comprise an optical phased array with beam steering across a 12° field of view in one axis. Tuning of the phased array is used to achieve 1.8°(steered axis)×0.6°(nonsteered axis) beam width with 7 dB background suppression for arbitrary beam direction within the field of view.

Harsh Environment Silicon Carbide Sensor Technology for Geothermal Instrumentation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pisano, Albert P.

2013-04-26

This project utilizes Silicon Carbide (SiC) materials platform to fabricate advanced sensors to be used as high-temperature downhole instrumentation for the DOE’s Geothermal Technologies Program on Enhanced Geothermal Systems. The scope of the proposed research is to 1) develop a SiC pressure sensor that can operate in harsh supercritical conditions, 2) develop a SiC temperature sensor that can operate in harsh supercritical conditions, 3) develop a bonding process for adhering SiC sensor die to well casing couplers, and 4) perform experimental exposure testing of sensor materials and the sensor devices.

Ultralow drive voltage silicon traveling-wave modulator.

PubMed

Baehr-Jones, Tom; Ding, Ran; Liu, Yang; Ayazi, Ali; Pinguet, Thierry; Harris, Nicholas C; Streshinsky, Matt; Lee, Poshen; Zhang, Yi; Lim, Andy Eu-Jin; Liow, Tsung-Yang; Teo, Selin Hwee-Gee; Lo, Guo-Qiang; Hochberg, Michael

2012-05-21

There has been great interest in the silicon platform as a material system for integrated photonics. A key challenge is the development of a low-power, low drive voltage, broadband modulator. Drive voltages at or below 1 Vpp are desirable for compatibility with CMOS processes. Here we demonstrate a CMOS-compatible broadband traveling-wave modulator based on a reverse-biased pn junction. We demonstrate operation with a drive voltage of 0.63 Vpp at 20 Gb/s, a significant improvement in the state of the art, with an RF energy consumption of only 200 fJ/bit.

Simultaneous dual-functioning InGaN/GaN multiple-quantum-well diode for transferrable optoelectronics

NASA Astrophysics Data System (ADS)

Shi, Zheng; Yuan, Jialei; Zhang, Shuai; Liu, Yuhuai; Wang, Yongjin

2017-10-01

We propose a wafer-level procedure for the fabrication of 1.5-mm-diameter dual functioning InGaN/GaN multiple-quantum-well (MQW) diodes on a GaN-on-silicon platform for transferrable optoelectronics. Nitride semiconductor materials are grown on (111) silicon substrates with intermediate Al-composition step-graded buffer layers, and membrane-type MQW-diode architectures are obtained by a combination of silicon removal and III-nitride film backside thinning. Suspended MQW-diodes are directly transferred from silicon to foreign substrates such as metal, glass and polyethylene terephthalate by mechanically breaking the support beams. The transferred MQW-diodes display strong electroluminescence under current injection and photodetection under light irradiation. Interestingly, they demonstrate a simultaneous light-emitting light-detecting function, endowing the 1.5-mm-diameter MQW-diode with the capability of producing transferrable optoelectronics for adjustable displays, wearable optical sensors, multifunctional energy harvesting, flexible light communication and monolithic photonic circuit.

Enhanced Single-Photon Emission from Carbon-Nanotube Dopant States Coupled to Silicon Microcavities.

PubMed

Ishii, Akihiro; He, Xiaowei; Hartmann, Nicolai F; Machiya, Hidenori; Htoon, Han; Doorn, Stephen K; Kato, Yuichiro K

2018-06-13

Single-walled carbon nanotubes are a promising material as quantum light sources at room temperature and as nanoscale light sources for integrated photonic circuits on silicon. Here, we show that the integration of dopant states in carbon nanotubes and silicon microcavities can provide bright and high-purity single-photon emitters on a silicon photonics platform at room temperature. We perform photoluminescence spectroscopy and observe the enhancement of emission from the dopant states by a factor of ∼50, and cavity-enhanced radiative decay is confirmed using time-resolved measurements, in which a ∼30% decrease of emission lifetime is observed. The statistics of photons emitted from the cavity-coupled dopant states are investigated by photon-correlation measurements, and high-purity single photon generation is observed. The excitation power dependence of photon emission statistics shows that the degree of photon antibunching can be kept high even when the excitation power increases, while the single-photon emission rate can be increased to ∼1.7 × 10 7 Hz.

Enhanced Single-Photon Emission from Carbon-Nanotube Dopant States Coupled to Silicon Microcavities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishii, Akihiro; He, Xiaowei; Hartmann, Nicolai F.

Single-walled carbon nanotubes are a promising material as quantum light sources at room temperature and as nanoscale light sources for integrated photonic circuits on silicon. Here, we show that the integration of dopant states in carbon nanotubes and silicon microcavities can provide bright and high-purity single-photon emitters on a silicon photonics platform at room temperature. We perform photoluminescence spectroscopy and observe the enhancement of emission from the dopant states by a factor of ~50, and cavity-enhanced radiative decay is confirmed using time-resolved measurements, in which a ~30% decrease of emission lifetime is observed. The statistics of photons emitted from themore » cavity-coupled dopant states are investigated by photon-correlation measurements, and high-purity single photon generation is observed. The excitation power dependence of photon emission statistics shows that the degree of photon antibunching can be kept high even when the excitation power increases, while the single-photon emission rate can be increased to ~1.7 × 10 7 Hz.« less

Observation of soliton compression in silicon photonic crystals

PubMed Central

Blanco-Redondo, A.; Husko, C.; Eades, D.; Zhang, Y.; Li, J.; Krauss, T.F.; Eggleton, B.J.

2014-01-01

Solitons are nonlinear waves present in diverse physical systems including plasmas, water surfaces and optics. In silicon, the presence of two photon absorption and accompanying free carriers strongly perturb the canonical dynamics of optical solitons. Here we report the first experimental demonstration of soliton-effect pulse compression of picosecond pulses in silicon, despite two photon absorption and free carriers. Here we achieve compression of 3.7 ps pulses to 1.6 ps with <10 pJ energy. We demonstrate a ~1-ps free-carrier-induced pulse acceleration and show that picosecond input pulses are critical to these observations. These experiments are enabled by a dispersion-engineered slow-light photonic crystal waveguide and an ultra-sensitive frequency-resolved electrical gating technique to detect the ultralow energies in the nanostructured device. Strong agreement with a nonlinear Schrödinger model confirms the measurements. These results further our understanding of nonlinear waves in silicon and open the way to soliton-based functionalities in complementary metal-oxide-semiconductor-compatible platforms. PMID:24423977

A review of molecular beam epitaxy of ferroelectric BaTiO 3 films on Si, Ge and GaAs substrates and their applications

DOE PAGES

Mazet, Lucie; Yang, Sang Mo; Kalinin, Sergei V.; ...

2015-06-30

SrTiO 3 epitaxial growth by molecular beam epitaxy (MBE) on silicon has opened up the route to the monolithic integration of various complex oxides on the complementary metal-oxide-semiconductor silicon platform. Among functional oxides, ferroelectric perovskite oxides offer promising perspectives to improve or add functionalities on-chip. We review the growth by MBE of the ferroelectric compound BaTiO 3 on silicon (Si), germanium (Ge) and gallium arsenide (GaAs) and we discuss the film properties in terms of crystalline structure, microstructure and ferroelectricity. Lastly, we review the last developments in two areas of interest for the applications of BaTiO 3 films on silicon,more » namely integrated photonics, which benefits from the large Pockels effect of BaTiO 3, and low power logic devices, which may benefit from the negative capacitance of the ferroelectric.« less

Ultra-compact resonant tunneling-based TE-pass and TM-pass polarizers for SOI platform.

PubMed

Azzam, Shaimaa I; Obayya, Salah S A

2015-03-15

We investigate the polarization-dependent resonance tunneling effect in silicon waveguides to achieve ultra-compact and highly efficient polarization fitters for integrated silicon photonics, to the best of our knowledge for the first time. We hence propose simple structures for silicon-on-insulator transverse electric (TE)-pass and transverse magnetic (TM)-pass polarizers based on the resonance tunneling effect in silicon waveguides. The suggested TE-pass polarizer has insertion losses (IL), extinction ratio (ER), and return losses (RL) of 0.004 dB, 18 dB, and 24 dB, respectively; whereas, the TM-pass polarizer is characterized by IL, ER, and RL of 0.15 dB, 20 dB, and 23 dB, respectively. Both polarizers have an ultra-short device length of only 1.35 and 1.31 μm for the TE-pass and the TM-pass polarizers which are the shortest reported lengths to the best of our knowledge.

Enhanced Single-Photon Emission from Carbon-Nanotube Dopant States Coupled to Silicon Microcavities

DOE PAGES

Ishii, Akihiro; He, Xiaowei; Hartmann, Nicolai F.; ...

2018-05-21

Single-walled carbon nanotubes are a promising material as quantum light sources at room temperature and as nanoscale light sources for integrated photonic circuits on silicon. Here, we show that the integration of dopant states in carbon nanotubes and silicon microcavities can provide bright and high-purity single-photon emitters on a silicon photonics platform at room temperature. We perform photoluminescence spectroscopy and observe the enhancement of emission from the dopant states by a factor of ~50, and cavity-enhanced radiative decay is confirmed using time-resolved measurements, in which a ~30% decrease of emission lifetime is observed. The statistics of photons emitted from themore » cavity-coupled dopant states are investigated by photon-correlation measurements, and high-purity single photon generation is observed. The excitation power dependence of photon emission statistics shows that the degree of photon antibunching can be kept high even when the excitation power increases, while the single-photon emission rate can be increased to ~1.7 × 10 7 Hz.« less

Silicon quantum processor with robust long-distance qubit couplings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tosi, Guilherme; Mohiyaddin, Fahd A.; Schmitt, Vivien

Practical quantum computers require a large network of highly coherent qubits, interconnected in a design robust against errors. Donor spins in silicon provide state-of-the-art coherence and quantum gate fidelities, in a platform adapted from industrial semiconductor processing. Here we present a scalable design for a silicon quantum processor that does not require precise donor placement and leaves ample space for the routing of interconnects and readout devices. We introduce the flip-flop qubit, a combination of the electron-nuclear spin states of a phosphorus donor that can be controlled by microwave electric fields. Two-qubit gates exploit a second-order electric dipole-dipole interaction, allowingmore » selective coupling beyond the nearest-neighbor, at separations of hundreds of nanometers, while microwave resonators can extend the entanglement to macroscopic distances. We predict gate fidelities within fault-tolerance thresholds using realistic noise models. This design provides a realizable blueprint for scalable spin-based quantum computers in silicon.« less

Ultracompact bottom-up photonic crystal lasers on silicon-on-insulator.

PubMed

Lee, Wook-Jae; Kim, Hyunseok; You, Jong-Bum; Huffaker, Diana L

2017-08-25

Compact on-chip light sources lie at the heart of practical nanophotonic devices since chip-scale photonic circuits have been regarded as the next generation computing tools. In this work, we demonstrate room-temperature lasing in 7 × 7 InGaAs/InGaP core-shell nanopillar array photonic crystals with an ultracompact footprint of 2300 × 2300 nm 2 , which are monolithically grown on silicon-on-insulator substrates. A strong lateral confinement is achieved by a photonic band-edge mode, which is leading to a strong light-matter interaction in the 7 × 7 nanopillar array, and by choosing an appropriate thickness of a silicon-on-insulator layer the band-edge mode can be trapped vertically in the nanopillars. The nanopillar array band-edge lasers exhibit single-mode operation, where the mode frequency is sensitive to the diameter of the nanopillars. Our demonstration represents an important first step towards developing practical and monolithic III-V photonic components on a silicon platform.

Multimedia consultation session recording and playback using Java-based browser in global PACS

NASA Astrophysics Data System (ADS)

Martinez, Ralph; Shah, Pinkesh J.; Yu, Yuan-Pin

1998-07-01

The current version of the Global PACS software system uses a Java-based implementation of the Remote Consultation and Diagnosis (RCD) system. The Java RCD includes a multimedia consultation session between physicians that includes text, static image, image annotation, and audio data. The JAVA RCD allows 2-4 physicians to collaborate on a patient case. It allows physicians to join the session via WWW Java-enabled browsers or stand alone RCD application. The RCD system includes a distributed database archive system for archiving and retrieving patient and session data. The RCD system can be used for store and forward scenarios, case reviews, and interactive RCD multimedia sessions. The RCD system operates over the Internet, telephone lines, or in a private Intranet. A multimedia consultation session can be recorded, and then played back at a later time for review, comments, and education. A session can be played back using Java-enabled WWW browsers on any operating system platform. The JAVA RCD system shows that a case diagnosis can be captured digitally and played back with the original real-time temporal relationships between data streams. In this paper, we describe design and implementation of the RCD session playback.

Formal Analysis of Self-Efficacy in Job Interviewee’s Mental State Model

NASA Astrophysics Data System (ADS)

Ajoge, N. S.; Aziz, A. A.; Yusof, S. A. Mohd

2017-08-01

This paper presents a formal analysis approach for self-efficacy model of interviewee’s mental state during a job interview session. Self-efficacy is a construct that has been hypothesised to combine with motivation and interviewee anxiety to define state influence of interviewees. The conceptual model was built based on psychological theories and models related to self-efficacy. A number of well-known relations between events and the course of self-efficacy are summarized from the literature and it is shown that the proposed model exhibits those patterns. In addition, this formal model has been mathematically analysed to find out which stable situations exist. Finally, it is pointed out how this model can be used in a software agent or robot-based platform. Such platform can provide an interview coaching approach where support to the user is provided based on their individual metal state during interview sessions.

Chemically Tunable Full Spectrum Optical Properties of 2D Silicon Telluride Nanoplates.

PubMed

Wang, Mengjing; Lahti, Gabriella; Williams, David; Koski, Kristie J

2018-06-07

Silicon telluride (Si 2 Te 3 ) is a two-dimensional, layered, p-type semiconductor that shows broad near-infrared photoluminescence. We show how, through various means of chemical modification, Si 2 Te 3 can have its optoelectronic properties modified in several independent ways without fundamentally altering the host crystalline lattice. Substitutional doping with Ge strongly redshifts the photoluminescence while substantially lowering the direct and indirect band gaps and altering the optical phonon modes. Intercalation with Ge introduces a sharp 4.3 eV ultraviolet resonance and shifts the bulk plasmon even while leaving the infrared response and band gaps virtually unchanged. Intercalation with copper strengthens the photoluminescence without altering its spectral shape. Thus silicon telluride is shown to be a chemically tunable platform of full spectrum optical properties promising for opto-electronic applications.

CMOS-Compatible Silicon Nanowire Field-Effect Transistor Biosensor: Technology Development toward Commercialization.

PubMed

Tran, Duy Phu; Pham, Thuy Thi Thanh; Wolfrum, Bernhard; Offenhäusser, Andreas; Thierry, Benjamin

2018-05-11

Owing to their two-dimensional confinements, silicon nanowires display remarkable optical, magnetic, and electronic properties. Of special interest has been the development of advanced biosensing approaches based on the field effect associated with silicon nanowires (SiNWs). Recent advancements in top-down fabrication technologies have paved the way to large scale production of high density and quality arrays of SiNW field effect transistor (FETs), a critical step towards their integration in real-life biosensing applications. A key requirement toward the fulfilment of SiNW FETs' promises in the bioanalytical field is their efficient integration within functional devices. Aiming to provide a comprehensive roadmap for the development of SiNW FET based sensing platforms, we critically review and discuss the key design and fabrication aspects relevant to their development and integration within complementary metal-oxide-semiconductor (CMOS) technology.

Porous silicon and diatoms micro-shells: an example of inverse biomimetic

NASA Astrophysics Data System (ADS)

De Tommasi, Edoardo; Rea, Ilaria; Rendina, Ivo; De Stefano, Luca

2011-05-01

Porous silicon (PSi) is by far a very useful technological platform for optical monitoring of chemical and biological substances and due to its peculiar physical and morphological properties it is worldwide used in sensing experiments. On the other hand, we have discovered a natural material, the micro-shells of marine diatoms, ubiquitous unicellular algae, which are made of hydrated amorphous silica, but, most of all, show geometrical structures made of complex patterns of pores which are surprisingly similar to those of porous silicon. Moreover, under laser irradiation, this material is photoluminescent and the photoluminescence is very sensitive to the surrounding atmosphere, which means that the material can act as a transducer. Starting from our experience on PSi devices, we explore the optical and photonic properties of marine diatoms micro-shells in a sort of inverse biomimicry.

Apparatus for sequentially transporting containers

NASA Technical Reports Server (NTRS)

Hudgins, J. L. (Inventor)

1982-01-01

Apparatus for transferring and manipulating a plurality of containers in a sequence is disclosed including a mechanical manipulator arm having a gripping device which automatically picks up a container at a fixed pickup position P and transfers it to a processing station. At a processing station X, the container is loaded with silicon wafers and thereafter returned by the arm to the fixed position P at the pickup and return station Y. A plurality of the containers may be processed in sequence from the fixed pickup position by providing a movable carriage upon which container pedestal platforms are supported, at least one of which is an elevator platform. The platforms include abutments for properly positioning the containers for accurate pickup by the manipulator arm.

TRIO Platform: A Novel Low Profile In vivo Imaging Support and Restraint System for Mice.

PubMed

Voziyanov, Vladislav; Kemp, Benjamin S; Dressel, Chelsea A; Ponder, Kayla; Murray, Teresa A

2016-01-01

High resolution, in vivo optical imaging of the mouse brain over time often requires anesthesia, which necessitates maintaining the animal's body temperature and level of anesthesia, as well as securing the head in an optimal, stable position. Controlling each parameter usually requires using multiple systems. Assembling multiple components into the small space on a standard microscope stage can be difficult and some commercially available parts simply do not fit. Furthermore, it is time-consuming to position an animal in the identical position over multiple imaging sessions for longitudinal studies. This is especially true when using an implanted gradient index (GRIN) lens for deep brain imaging. The multiphoton laser beam must be parallel with the shaft of the lens because even a slight tilt of the lens can degrade image quality. In response to these challenges, we have designed a compact, integrated in vivo imaging support system to overcome the problems created by using separate systems during optical imaging in mice. It is a single platform that provides (1) sturdy head fixation, (2) an integrated gas anesthesia mask, and (3) safe warm water heating. This THREE-IN-ONE (TRIO) Platform has a small footprint and a low profile that positions a mouse's head only 20 mm above the microscope stage. This height is about one half to one third the height of most commercially available immobilization devices. We have successfully employed this system, using isoflurane in over 40 imaging sessions with an average of 2 h per session with no leaks or other malfunctions. Due to its smaller size, the TRIO Platform can be used with a wider range of upright microscopes and stages. Most of the components were designed in SOLIDWORKS® and fabricated using a 3D printer. This additive manufacturing approach also readily permits size modifications for creating systems for other small animals.

TRIO Platform: A Novel Low Profile In vivo Imaging Support and Restraint System for Mice

PubMed Central

Voziyanov, Vladislav; Kemp, Benjamin S.; Dressel, Chelsea A.; Ponder, Kayla; Murray, Teresa A.

2016-01-01

High resolution, in vivo optical imaging of the mouse brain over time often requires anesthesia, which necessitates maintaining the animal's body temperature and level of anesthesia, as well as securing the head in an optimal, stable position. Controlling each parameter usually requires using multiple systems. Assembling multiple components into the small space on a standard microscope stage can be difficult and some commercially available parts simply do not fit. Furthermore, it is time-consuming to position an animal in the identical position over multiple imaging sessions for longitudinal studies. This is especially true when using an implanted gradient index (GRIN) lens for deep brain imaging. The multiphoton laser beam must be parallel with the shaft of the lens because even a slight tilt of the lens can degrade image quality. In response to these challenges, we have designed a compact, integrated in vivo imaging support system to overcome the problems created by using separate systems during optical imaging in mice. It is a single platform that provides (1) sturdy head fixation, (2) an integrated gas anesthesia mask, and (3) safe warm water heating. This THREE-IN-ONE (TRIO) Platform has a small footprint and a low profile that positions a mouse's head only 20 mm above the microscope stage. This height is about one half to one third the height of most commercially available immobilization devices. We have successfully employed this system, using isoflurane in over 40 imaging sessions with an average of 2 h per session with no leaks or other malfunctions. Due to its smaller size, the TRIO Platform can be used with a wider range of upright microscopes and stages. Most of the components were designed in SOLIDWORKS® and fabricated using a 3D printer. This additive manufacturing approach also readily permits size modifications for creating systems for other small animals. PMID:27199633

Efficacy of a Human Papillomavirus Vaccination Educational Platform in a Diverse Urban Population.

PubMed

Weinstein, Jacqueline E; Ananth, Ashwin; Brunner, Jacob P; Nelson, Ryan E; Bateman, Marjorie E; Carter, John M; Buell, Joseph F; Friedlander, Paul L

2016-06-01

Human papillomavirus (HPV) is a preventable disease that plays a causative role in a significant proportion of malignant neoplasms of the head and neck. Inner-city populations are at risk for HPV-related oropharyngeal cancer, are least likely to receive HPV vaccination, and report a lack of information regarding HPV. To determine whether an educational platform affects knowledge, attitudes, and practices regarding HPV vaccination in an inner-city community. This prospective cohort study, conducted from March 1 to December 31, 2014, surveyed 128 participants at multiple inner-city community centers regarding their knowledge of, attitudes toward, and practices regarding HPV vaccination before and after a brief educational presentation. No eligible individuals refused to participate in the educational session. Surveys were excluded from analysis if they were incomplete. Participants completed two 20-question surveys separated by a 15-minute educational session on HPV-related disease, including a short PowerPoint presentation. Presence of statistically significant differences in survey scores before and after the educational session. Eighty-six participants met eligibility criteria (61 male [70.9%]; 68 with a high school education [79.1%]). Baseline knowledge of HPV, its causal association with cancer, and the existence of a vaccine against HPV were poor: of a total composite score of 20, the mean knowledge score before the educational session was 9.69. Participants' self-rated knowledge regarding HPV disease and vaccination improved significantly as a result of the educational session; the absolute increase in mean knowledge composite score from before the educational session to after the session was 3.52 (17.6%) (95% CI, -2.87 to 9.92; P < .01). Attitudes regarding government involvement in vaccination did not change as a result of the educational session (composite attitudes score before the educational session, 16.57 of 28; score after the session, 15.22; P = .98). Participants' intent to vaccinate their children increased significantly following the educational presentation: before the presentation, 34 respondents (40%) intended to have their children vaccinated; after the presentation, 60 (70%) intended to do so (P = .002). Lack of knowledge regarding HPV vaccination and unwillingness to undergo vaccination contribute to low rates of HPV vaccination within urban populations. Community-based educational sessions successfully teach the link between HPV and various cancers, provide information regarding the risks and benefits of vaccination, and increase participants' willingness to vaccinate their children against HPV. Attitudes regarding government involvement in health programs are resistant to change.

Dielectric Metasurface as a Platform for Spatial Mode Conversion in Nanoscale Waveguides.

PubMed

Ohana, David; Desiatov, Boris; Mazurski, Noa; Levy, Uriel

2016-12-14

We experimentally demonstrate a nanoscale mode converter that performs coupling between the first two transverse electric-like modes of a silicon-on-insulator waveguide. The device operates by introducing a nanoscale periodic perturbation in its effective refractive index along the propagation direction and a graded effective index profile along its transverse direction. The periodic perturbation provides phase matching between the modes, while the graded index profile, which is realized by the implementation of nanoscale dielectric metasurface consisting of silicon features that are etched into the waveguide taking advantage of the effective medium concept, provides the overlap between the modes. Following the device design and numerical analysis using three-dimensional finite difference time domain simulations, we have fabricated the device and characterized it by directly measuring the modal content using optical imaging microscopy. From these measurements, the mode purity is estimated to be 95% and the transmission relative to an unperturbed strip waveguide is as high as 88%. Finally, we extend this approach to accommodate for the coupling between photonic and plasmonic modes. Specifically, we design and numerically demonstrate photonic to plasmonic mode conversion in a hybrid waveguide in which photonic and surface plasmon polariton modes can be guided in the silicon core and in the silicon/metal interface, respectively. The same method can also be used for coupling between symmetric and antisymmetric plasmonic modes in metal-insulator-metal or insulator-metal-insulator structures. On the basis of the current demonstration, we believe that such nanoscale dielectric metasurface-based mode converters can now be realized and become an important building block in future nanoscale photonic and plasmonic devices. Furthermore, the demonstrated platform can be used for the implementation of other chip scale components such as splitters, combiners couplers, and more.

Integrated Optics for Planar imaging and Optical Signal Processing

NASA Astrophysics Data System (ADS)

Song, Qi

Silicon photonics is a subject of growing interest with the potential of delivering planar electro-optical devices with chip scale integration. Silicon-on-insulator (SOI) technology has provided a marvelous platform for photonics industry because of its advantages in integration capability in CMOS circuit and countless nonlinearity applications in optical signal processing. This thesis is focused on the investigation of planar imaging techniques on SOI platform and potential applications in ultra-fast optical signal processing. In the first part, a general review and background introduction about integrated photonics circuit and planar imaging technique are provided. In chapter 2, planar imaging platform is realized by a silicon photodiode on SOI chip. Silicon photodiode on waveguide provides a high numerical aperture for an imaging transceiver pixel. An erbium doped Y2O3 particle is excited by 1550nm Laser and the fluorescent image is obtained with assistance of the scanning system. Fluorescence image is reconstructed by using image de-convolution technique. Under photovoltaic mode, we use an on-chip photodiode and an external PIN photodiode to realize similar resolution as 5μm. In chapter 3, a time stretching technique is developed to a spatial domain to realize a 2D imaging system as an ultrafast imaging tool. The system is evaluated based on theoretical calculation. The experimental results are shown for a verification of system capability to imaging a micron size particle or a finger print. Meanwhile, dynamic information for a moving object is also achieved by correlation algorithm. In chapter 4, the optical leaky wave antenna based on SOI waveguide has been utilized for imaging applications and extensive numerical studied has been conducted. and the theoretical explanation is supported by leaky wave theory. The highly directive radiation has been obtained from the broadside with 15.7 dB directivity and a 3dB beam width of ΔØ 3dB ≈ 1.65° in free space environment when β -1 = 2.409 × 105/m, α=4.576 ×103/m. At the end, electronics beam-steering principle has been studied and the comprehensive model has been built to explain carrier transformation behavior in a PIN junction as individual silicon perturbation. Results show that 1019/cm3 is possible obtained with electron injection mechanism. Although the radiation modulation based on carrier injection of 1019/cm3 gives 0.5dB variation, resonant structure, such as Fabry Perrot Cavity, can be integrated with LOWAs to enhance modulation effect.

A Randomized Trial Comparing Classical Participatory Design to VandAID, an Interactive CrowdSourcing Platform to Facilitate User-centered Design.

PubMed

Dufendach, Kevin R; Koch, Sabine; Unertl, Kim M; Lehmann, Christoph U

2017-10-26

Early involvement of stakeholders in the design of medical software is particularly important due to the need to incorporate complex knowledge and actions associated with clinical work. Standard user-centered design methods include focus groups and participatory design sessions with individual stakeholders, which generally limit user involvement to a small number of individuals due to the significant time investments from designers and end users. The goal of this project was to reduce the effort for end users to participate in co-design of a software user interface by developing an interactive web-based crowdsourcing platform. In a randomized trial, we compared a new web-based crowdsourcing platform to standard participatory design sessions. We developed an interactive, modular platform that allows responsive remote customization and design feedback on a visual user interface based on user preferences. The responsive canvas is a dynamic HTML template that responds in real time to user preference selections. Upon completion, the design team can view the user's interface creations through an administrator portal and download the structured selections through a REDCap interface. We have created a software platform that allows users to customize a user interface and see the results of that customization in real time, receiving immediate feedback on the impact of their design choices. Neonatal clinicians used the new platform to successfully design and customize a neonatal handoff tool. They received no specific instruction and yet were able to use the software easily and reported high usability. VandAID, a new web-based crowdsourcing platform, can involve multiple users in user-centered design simultaneously and provides means of obtaining design feedback remotely. The software can provide design feedback at any stage in the design process, but it will be of greatest utility for specifying user requirements and evaluating iterative designs with multiple options.

Smart Sensor Systems for Aerospace Applications: From Sensor Development to Application Testing

NASA Technical Reports Server (NTRS)

Hunter, G. W.; Xu, J. C.; Dungan, L. K.; Ward, B. J.; Rowe, S.; Williams, J.; Makel, D. B.; Liu, C. C.; Chang, C. W.

2008-01-01

The application of Smart Sensor Systems for aerospace applications is a multidisciplinary process consisting of sensor element development, element integration into Smart Sensor hardware, and testing of the resulting sensor systems in application environments. This paper provides a cross-section of these activities for multiple aerospace applications illustrating the technology challenges involved. The development and application testing topics discussed are: 1) The broadening of sensitivity and operational range of silicon carbide (SiC) Schottky gas sensor elements; 2) Integration of fire detection sensor technology into a "Lick and Stick" Smart Sensor hardware platform for Crew Exploration Vehicle applications; 3) Extended testing for zirconia based oxygen sensors in the basic "Lick and Stick" platform for environmental monitoring applications. It is concluded that that both core sensor platform technology and a basic hardware platform can enhance the viability of implementing smart sensor systems in aerospace applications.

Comparative Performance of Linear Multielectrode Probes and Single-Tip Electrodes for Intracortical Microstimulation and Single-Neuron Recording in Macaque Monkey

PubMed Central

Ferroni, Carolina G.; Maranesi, Monica; Livi, Alessandro; Lanzilotto, Marco; Bonini, Luca

2017-01-01

Intracortical microstimulation (ICMS) is one of the most widely employed techniques for providing causal evidence of the relationship between neuronal activity and specific motor, perceptual, or even cognitive functions. In recent years, several new types of linear multielectrode silicon probes have been developed, allowing researchers to sample neuronal activity at different depths along the same cortical site simultaneously and with high spatial precision. Nevertheless, silicon multielectrode probes have been rarely employed for ICMS studies and, more importantly, it is unknown whether and to what extent they can be used for combined recording and stimulation experiments. Here, we addressed these issues during both acute and chronic conditions. First, we compared the behavioral outcomes of ICMS delivered to the hand region of a monkey's motor cortex with multielectrode silicon probes, commercially available multisite stainless-steel probes and single-tip glass-coated tungsten microelectrodes. The results for all three of the probes were reliable and similar. Furthermore, we tested the impact of long-train ICMS delivered through chronically implanted silicon probes at different time intervals, from 1 to 198 days after ICMS sessions, showing that although the number of recorded neurons decreased over time, in line with previous studies, ICMS did not alter silicon probes' recording capabilities. These findings indicate that in ICMS experiments, the performance of linear multielectrode silicon probes is comparable to that of both single-tip and multielectrode stainless-steel probes, suggesting that the silicon probes can be successfully used for combined recording and stimulation studies in chronic conditions. PMID:29187815

Comparative Performance of Linear Multielectrode Probes and Single-Tip Electrodes for Intracortical Microstimulation and Single-Neuron Recording in Macaque Monkey.

PubMed

Ferroni, Carolina G; Maranesi, Monica; Livi, Alessandro; Lanzilotto, Marco; Bonini, Luca

2017-01-01

Intracortical microstimulation (ICMS) is one of the most widely employed techniques for providing causal evidence of the relationship between neuronal activity and specific motor, perceptual, or even cognitive functions. In recent years, several new types of linear multielectrode silicon probes have been developed, allowing researchers to sample neuronal activity at different depths along the same cortical site simultaneously and with high spatial precision. Nevertheless, silicon multielectrode probes have been rarely employed for ICMS studies and, more importantly, it is unknown whether and to what extent they can be used for combined recording and stimulation experiments. Here, we addressed these issues during both acute and chronic conditions. First, we compared the behavioral outcomes of ICMS delivered to the hand region of a monkey's motor cortex with multielectrode silicon probes, commercially available multisite stainless-steel probes and single-tip glass-coated tungsten microelectrodes. The results for all three of the probes were reliable and similar. Furthermore, we tested the impact of long-train ICMS delivered through chronically implanted silicon probes at different time intervals, from 1 to 198 days after ICMS sessions, showing that although the number of recorded neurons decreased over time, in line with previous studies, ICMS did not alter silicon probes' recording capabilities. These findings indicate that in ICMS experiments, the performance of linear multielectrode silicon probes is comparable to that of both single-tip and multielectrode stainless-steel probes, suggesting that the silicon probes can be successfully used for combined recording and stimulation studies in chronic conditions.

Silicon quantum processor with robust long-distance qubit couplings.

PubMed

Tosi, Guilherme; Mohiyaddin, Fahd A; Schmitt, Vivien; Tenberg, Stefanie; Rahman, Rajib; Klimeck, Gerhard; Morello, Andrea

2017-09-06

Practical quantum computers require a large network of highly coherent qubits, interconnected in a design robust against errors. Donor spins in silicon provide state-of-the-art coherence and quantum gate fidelities, in a platform adapted from industrial semiconductor processing. Here we present a scalable design for a silicon quantum processor that does not require precise donor placement and leaves ample space for the routing of interconnects and readout devices. We introduce the flip-flop qubit, a combination of the electron-nuclear spin states of a phosphorus donor that can be controlled by microwave electric fields. Two-qubit gates exploit a second-order electric dipole-dipole interaction, allowing selective coupling beyond the nearest-neighbor, at separations of hundreds of nanometers, while microwave resonators can extend the entanglement to macroscopic distances. We predict gate fidelities within fault-tolerance thresholds using realistic noise models. This design provides a realizable blueprint for scalable spin-based quantum computers in silicon.Quantum computers will require a large network of coherent qubits, connected in a noise-resilient way. Tosi et al. present a design for a quantum processor based on electron-nuclear spins in silicon, with electrical control and coupling schemes that simplify qubit fabrication and operation.

Dissolution of Monocrystalline Silicon Nanomembranes and Their Use as Encapsulation Layers and Electrical Interfaces in Water-Soluble Electronics.

PubMed

Lee, Yoon Kyeung; Yu, Ki Jun; Song, Enming; Barati Farimani, Amir; Vitale, Flavia; Xie, Zhaoqian; Yoon, Younghee; Kim, Yerim; Richardson, Andrew; Luan, Haiwen; Wu, Yixin; Xie, Xu; Lucas, Timothy H; Crawford, Kaitlyn; Mei, Yongfeng; Feng, Xue; Huang, Yonggang; Litt, Brian; Aluru, Narayana R; Yin, Lan; Rogers, John A

2017-12-26

The chemistry that governs the dissolution of device-grade, monocrystalline silicon nanomembranes into benign end products by hydrolysis serves as the foundation for fully eco/biodegradable classes of high-performance electronics. This paper examines these processes in aqueous solutions with chemical compositions relevant to groundwater and biofluids. The results show that the presence of Si(OH) 4 and proteins in these solutions can slow the rates of dissolution and that ion-specific effects associated with Ca 2+ can significantly increase these rates. This information allows for effective use of silicon nanomembranes not only as active layers in eco/biodegradable electronics but also as water barriers capable of providing perfect encapsulation until their disappearance by dissolution. The time scales for this encapsulation can be controlled by introduction of dopants into the Si and by addition of oxide layers on the exposed surfaces.The former possibility also allows the doped silicon to serve as an electrical interface for measuring biopotentials, as demonstrated in fully bioresorbable platforms for in vivo neural recordings. This collection of findings is important for further engineering development of water-soluble classes of silicon electronics.

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

PubMed Central

Rossi, Alessandro; Tanttu, Tuomo; Hudson, Fay E.; Sun, Yuxin; Möttönen, Mikko; Dzurak, Andrew S.

2015-01-01

As mass-produced silicon transistors have reached the nano-scale, their behavior and performances are increasingly affected, and often deteriorated, by quantum mechanical effects such as tunneling through single dopants, scattering via interface defects, and discrete trap charge states. However, progress in silicon technology has shown that these phenomena can be harnessed and exploited for a new class of quantum-based electronics. Among others, multi-layer-gated silicon metal-oxide-semiconductor (MOS) technology can be used to control single charge or spin confined in electrostatically-defined quantum dots (QD). These QD-based devices are an excellent platform for quantum computing applications and, recently, it has been demonstrated that they can also be used as single-electron pumps, which are accurate sources of quantized current for metrological purposes. Here, we discuss in detail the fabrication protocol for silicon MOS QDs which is relevant to both quantum computing and quantum metrology applications. Moreover, we describe characterization methods to test the integrity of the devices after fabrication. Finally, we give a brief description of the measurement set-up used for charge pumping experiments and show representative results of electric current quantization. PMID:26067215

Effects of the antidepressant drug moclobemide on learning and memory in rats.

PubMed

Getova, D; Dimitrova, D; Roukounakis, I

2003-12-01

Moclobemide is a well known drug with antidepressant action. The aim of this study was to investigate the effects of moclobemide on learning and memory processes in Sprague Dawley rats. Over a 5-day period, learning sessions with 30 trials per day and memory retention tests were performed. The conditioned responses (avoidances), the unconditioned responses (escapes) and the intertrial crossings were observed. An active avoidance test was carried out using a shuttle box. Two passive avoidance tests were used: step-through (using a light chamber) and step-down (using a platform). In the step-through passive avoidance test, the learning and retention sessions consisted of three trials each and the latency of reaction times (the rat remaining in the light chamber for more than 180 sec) was used as criterion. In the step-down passive avoidance test, learning and retention sessions consisted of two trials and the latency of reaction times (the rat remaining on the platform for 60 sec) was used as criterion. In the active avoidance tests, moclobemide dose-dependently increased the number of avoidances during learning sessions and maintained this number in memory retention tests. Moclobemide did not alter the number of escapes, but did increase motor activity. In the passive avoidance tests, moclobemide also increased the latency of reaction times in learning and short memory retrieval tests. These findings suggest that moclobemide improves learning and memory processes in active and passive avoidance tests and has a cognition-enhancing effect. (c) 2003 Prous Science

Microfluidic assembly of monodisperse multistage pH-responsive polymer/porous silicon composites for precisely controlled multi-drug delivery.

PubMed

Liu, Dongfei; Zhang, Hongbo; Herranz-Blanco, Bárbara; Mäkilä, Ermei; Lehto, Vesa-Pekka; Salonen, Jarno; Hirvonen, Jouni; Santos, Hélder A

2014-05-28

We report an advanced drug delivery platform for combination chemotherapy by concurrently incorporating two different drugs into microcompoistes with ratiometric control over the loading degree. Atorvastatin and celecoxib were selected as model drugs due to their different physicochemical properties and synergetic effect on colorectal cancer prevention and inhibition. To be effective in colorectal cancer prevention and inhibition, the produced microcomposite contained hypromellose acetate succinate, which is insoluble in acidic conditions but highly dissolving at neutral or alkaline pH conditions. Taking advantage of the large pore volume of porous silicon (PSi), atorvastatin was firstly loaded into the PSi matrix, and then encapsulated into the pH-responsive polymer microparticles containing celecoxib by microfluidics in order to obtain multi-drug loaded polymer/PSi microcomposites. The prepared microcomposites showed monodisperse size distribution, multistage pH-response, precise ratiometric controlled loading degree towards the simultaneously loaded drug molecules, and tailored release kinetics of the loaded cargos. This attractive microcomposite platform protects the payloads from being released at low pH-values, and enhances their release at higher pH-values, which can be further used for colon cancer prevention and treatment. Overall, the pH-responsive polymer/PSi-based microcomposite can be used as a universal platform for the delivery of different drug molecules for combination therapy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design analysis of doped-silicon surface plasmon resonance immunosensors in mid-infrared range.

PubMed

DiPippo, William; Lee, Bong Jae; Park, Keunhan

2010-08-30

This paper reports the design analysis of a microfabricatable mid-infrared (mid-IR) surface plasmon resonance (SPR) sensor platform. The proposed platform has periodic heavily doped profiles implanted into intrinsic silicon and a thin gold layer deposited on top, making a physically flat grating SPR coupler. A rigorous coupled-wave analysis was conducted to prove the design feasibility, characterize the sensor's performance, and determine geometric parameters of the heavily doped profiles. Finite element analysis (FEA) was also employed to compute the electromagnetic field distributions at the plasmon resonance. Obtained results reveal that the proposed structure can excite the SPR on the normal incidence of mid-IR light, resulting in a large probing depth that will facilitate the study of larger analytes. Furthermore, the whole structure can be microfabricated with well-established batch protocols, providing tunability in the SPR excitation wavelength for specific biosensing needs with a low manufacturing cost. When the SPR sensor is to be used in a Fourier-transform infrared (FTIR) spectroscopy platform, its detection sensitivity and limit of detection are estimated to be 3022 nm/RIU and ~70 pg/mm(2), respectively, at a sample layer thickness of 100 nm. The design analysis performed in the present study will allow the fabrication of a tunable, disposable mid-IR SPR sensor that combines advantages of conventional prism and metallic grating SPR sensors.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scigaj, M.; Chao, C. H.; Gázquez, J.

The integration of epitaxial BaTiO 3 films on silicon, combining c-orientation, surface flatness, and high ferroelectric polarization is of main interest towards its use in memory devices. This combination of properties has been only achieved so far by using yttria-stabilized zirconia buffer layers. Here, the all-perovskite BaTiO 3/LaNiO 3/SrTiO 3 heterostructure is grown monolithically on Si(001). The BaTiO 3 films are epitaxial and c-oriented and present low surface roughness and high remnant ferroelectric polarization around 6 μC/cm 2. Lastly, this result paves the way towards the fabrication of lead-free BaTiO 3 ferroelectric memories on silicon platforms.

Porous Silicon Structures as Optical Gas Sensors.

PubMed

Levitsky, Igor A

2015-08-14

We present a short review of recent progress in the field of optical gas sensors based on porous silicon (PSi) and PSi composites, which are separate from PSi optochemical and biological sensors for a liquid medium. Different periodical and nonperiodical PSi photonic structures (bares, modified by functional groups or infiltrated with sensory polymers) are described for gas sensing with an emphasis on the device specificity, sensitivity and stability to the environment. Special attention is paid to multiparametric sensing and sensor array platforms as effective trends for the improvement of analyte classification and quantification. Mechanisms of gas physical and chemical sorption inside PSi mesopores and pores of PSi functional composites are discussed.

2 μm wavelength range InP-based type-II quantum well photodiodes heterogeneously integrated on silicon photonic integrated circuits.

PubMed

Wang, Ruijun; Sprengel, Stephan; Muneeb, Muhammad; Boehm, Gerhard; Baets, Roel; Amann, Markus-Christian; Roelkens, Gunther

2015-10-05

The heterogeneous integration of InP-based type-II quantum well photodiodes on silicon photonic integrated circuits for the 2 µm wavelength range is presented. A responsivity of 1.2 A/W at a wavelength of 2.32 µm and 0.6 A/W at 2.4 µm wavelength is demonstrated. The photodiodes have a dark current of 12 nA at -0.5 V at room temperature. The absorbing active region of the integrated photodiodes consists of six periods of a "W"-shaped quantum well, also allowing for laser integration on the same platform.

Deuterated silicon nitride photonic devices for broadband optical frequency comb generation

NASA Astrophysics Data System (ADS)

Chiles, Jeff; Nader, Nima; Hickstein, Daniel D.; Yu, Su Peng; Briles, Travis Crain; Carlson, David; Jung, Hojoong; Shainline, Jeffrey M.; Diddams, Scott; Papp, Scott B.; Nam, Sae Woo; Mirin, Richard P.

2018-04-01

We report and characterize low-temperature, plasma-deposited deuterated silicon nitride thin films for nonlinear integrated photonics. With a peak processing temperature less than 300$^\\circ$C, it is back-end compatible with pre-processed CMOS substrates. We achieve microresonators with a quality factor of up to $1.6\\times 10^6 $ at 1552 nm, and $>1.2\\times 10^6$ throughout $\\lambda$ = 1510 -- 1600 nm, without annealing or stress management. We then demonstrate the immediate utility of this platform in nonlinear photonics by generating a 1 THz free spectral range, 900-nm-bandwidth modulation-instability microresonator Kerr comb and octave-spanning, supercontinuum-broadened spectra.

Silicon carbide novel optical sensor for combustion systems and nuclear reactors

NASA Astrophysics Data System (ADS)

Lim, Geunsik; Kar, Aravinda

2014-09-01

Crystalline silicon carbide is a wide bandgap semiconductor material with excellent optical properties, chemical inertness, radiation hardness and high mechanical strength at high temperatures. It is an excellent material platform for sensor applications in harsh environments such as combustion systems and nuclear reactors. A laser doping technique is used to fabricate SiC sensors for different combustion gases such as CO2, CO, NO and NO2. The sensor operates based on the principle of semiconductor optics, producing optical signal in contrast to conventional electrical sensors that produces electrical signal. The sensor response is measured with a low power He-Ne or diode laser.

Si-based optical I/O for optical memory interface

NASA Astrophysics Data System (ADS)

Ha, Kyoungho; Shin, Dongjae; Byun, Hyunil; Cho, Kwansik; Na, Kyoungwon; Ji, Hochul; Pyo, Junghyung; Hong, Seokyong; Lee, Kwanghyun; Lee, Beomseok; Shin, Yong-hwack; Kim, Junghye; Kim, Seong-gu; Joe, Insung; Suh, Sungdong; Choi, Sanghoon; Han, Sangdeok; Park, Yoondong; Choi, Hanmei; Kuh, Bongjin; Kim, Kichul; Choi, Jinwoo; Park, Sujin; Kim, Hyeunsu; Kim, Kiho; Choi, Jinyong; Lee, Hyunjoo; Yang, Sujin; Park, Sungho; Lee, Minwoo; Cho, Minchang; Kim, Saebyeol; Jeong, Taejin; Hyun, Seokhun; Cho, Cheongryong; Kim, Jeong-kyoum; Yoon, Hong-gu; Nam, Jeongsik; Kwon, Hyukjoon; Lee, Hocheol; Choi, Junghwan; Jang, Sungjin; Choi, Joosun; Chung, Chilhee

2012-01-01

Optical interconnects may provide solutions to the capacity-bandwidth trade-off of recent memory interface systems. For cost-effective optical memory interfaces, Samsung Electronics has been developing silicon photonics platforms on memory-compatible bulk-Si 300-mm wafers. The waveguide of 0.6 dB/mm propagation loss, vertical grating coupler of 2.7 dB coupling loss, modulator of 10 Gbps speed, and Ge/Si photodiode of 12.5 Gbps bandwidth have been achieved on the bulk-Si platform. 2x6.4 Gbps electrical driver circuits have been also fabricated using a CMOS process.

Development of an electro-responsive platform for the controlled transfection of mammalian cells

NASA Astrophysics Data System (ADS)

Hook, Andrew L.; Thissen, Helmut W.; Hayes, Jason P.; Voelcker, Nicolas H.

2005-02-01

The recent development of living microarrays as novel tools for the analysis of gene expression in an in-situ environment promises to unravel gene function within living organisms. In order to significantly enhance microarray performance, we are working towards electro-responsive DNA transfection chips. This study focuses on the control of DNA adsorption and desorption by appropriate surface modification of highly doped p++ silicon. Silicon was modified by plasma polymerisation of allylamine (ALAPP), a non-toxic surface that sustains cell growth. Subsequent high surface density grafting of poly(ethylene oxide) formed a layer resistant to biomolecule adsorption and cell attachment. Spatially controlled excimer laser ablation of the surface produced micron resolution patterns of re-exposed plasma polymer whilst the rest of the surface remained non-fouling. We observed electro-stimulated preferential adsorption of DNA to the ALAPP surface and subsequent desorption by the application of a negative bias. Cell culture experiments with HEK 293 cells demonstrated efficient and controlled transfection of cells using the expression of green fluorescent protein as a reporter. Thus, these chemically patterned surfaces are promising platforms for use as living microarrays.

Probing low noise at the MOS interface with a spin-orbit qubit.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jock, Ryan Michael; Jacobson, Noah Tobias; Harvey-Collard, Patrick

The silicon metal-oxide-semiconductor (MOS) material system is technologically important for the implementation of electron spin-based quantum information technologies. Researchers predict the need for an integrated platform in order to implement useful computation, and decades of advancements in silicon microelectronics fabrication lends itself to this challenge. However, fundamental concerns have been raised about the MOS interface (e.g. trap noise, variations in electron g-factor and practical implementation of multi-QDs). Furthermore, two-axis control of silicon qubits has, to date, required the integration of non-ideal components (e.g. microwave strip-lines, micro-magnets, triple quantum dots, or introduction of donor atoms). In this paper, we introduce amore » spin-orbit (SO) driven singlet- triplet (ST) qubit in silicon, demonstrating all-electrical two-axis control that requires no additional integrated elements and exhibits charge noise properties equivalent to other more model, but less commercially mature, semiconductor systems. We demonstrate the ability to tune an intrinsic spin-orbit interface effect, which is consistent with Rashba and Dresselhaus contributions that are remarkably strong for a low spin-orbit material such as silicon. The qubit maintains the advantages of using isotopically enriched silicon for producing a quiet magnetic environment, measuring spin dephasing times of 1.6 μs using 99.95% 28Si epitaxy for the qubit, comparable to results from other isotopically enhanced silicon ST qubit systems. This work, therefore, demonstrates that the interface inherently provides properties for two-axis control, and the technologically important MOS interface does not add additional detrimental qubit noise. isotopically enhanced silicon ST qubit systems« less

Breakthrough cancer medicine and its impact on novel drug development in China: report of the US Chinese Anti-Cancer Association (USCACA) and Chinese Society of Clinical Oncology (CSCO) Joint Session at the 17th CSCO Annual Meeting.

PubMed

Luo, Feng Roger; Ding, Jian; Chen, Helen X; Liu, Hao; Fung, Man-Cheong; Koehler, Maria; Armand, Jean Pierre; Jiang, Lei; Xu, Xiao; Zhang, Ge; Xu, Li; Qian, Pascal; Yan, Li

2014-12-01

The US Chinese Anti-Cancer Association (USCACA) teamed up with Chinese Society of Clinical Oncology (CSCO) to host a joint session at the17th CSCO Annual Meeting on September 20th, 2014 in Xiamen, China. With a focus on breakthrough cancer medicines, the session featured innovative approaches to evaluate breakthrough agents and established a platform to interactively share successful experiences from case studies of 6 novel agents from both the United States and China. The goal of the session is to inspire scientific and practical considerations for clinical trial design and strategy to expedite cancer drug development in China. A panel discussion further provided in-depth advice on advancing both early and full development of novel cancer medicines in China.

Printable nanostructured silicon solar cells for high-performance, large-area flexible photovoltaics.

PubMed

Lee, Sung-Min; Biswas, Roshni; Li, Weigu; Kang, Dongseok; Chan, Lesley; Yoon, Jongseung

2014-10-28

Nanostructured forms of crystalline silicon represent an attractive materials building block for photovoltaics due to their potential benefits to significantly reduce the consumption of active materials, relax the requirement of materials purity for high performance, and hence achieve greatly improved levelized cost of energy. Despite successful demonstrations for their concepts over the past decade, however, the practical application of nanostructured silicon solar cells for large-scale implementation has been hampered by many existing challenges associated with the consumption of the entire wafer or expensive source materials, difficulties to precisely control materials properties and doping characteristics, or restrictions on substrate materials and scalability. Here we present a highly integrable materials platform of nanostructured silicon solar cells that can overcome these limitations. Ultrathin silicon solar microcells integrated with engineered photonic nanostructures are fabricated directly from wafer-based source materials in configurations that can lower the materials cost and can be compatible with deterministic assembly procedures to allow programmable, large-scale distribution, unlimited choices of module substrates, as well as lightweight, mechanically compliant constructions. Systematic studies on optical and electrical properties, photovoltaic performance in experiments, as well as numerical modeling elucidate important design rules for nanoscale photon management with ultrathin, nanostructured silicon solar cells and their interconnected, mechanically flexible modules, where we demonstrate 12.4% solar-to-electric energy conversion efficiency for printed ultrathin (∼ 8 μm) nanostructured silicon solar cells when configured with near-optimal designs of rear-surface nanoposts, antireflection coating, and back-surface reflector.

Methane Trace-Gas Sensing Enabled by Silicon Photonic Integration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, William

Fugitive methane leaks occurring during extraction at typical natural gas wells have an adverse environmental impact due to the methane’s large radiative forcing, in addition to reducing the producer’s overall efficiency and cost. Mitigation of these concerns can benefit from cost-effective sensor nodes, performing reliable, rapid and continuous tracking of methane emissions. The efficacy of laser spectroscopy has been widely demonstrated in both environmental and medical applications due to its sensitivity and specificity to the target analyte. However, the present cost and lack of manufacturing scalability of traditional free-space optical systems can limit their viability for deployment in economical wide-areamore » sensor networks. This presentation will review the development and performance of a cost-effective silicon photonic trace gas sensing platform that leverages silicon photonic waveguide and packaging technologies to perform on-chip evanescent field spectroscopy of methane.« less

A CMOS silicon spin qubit

PubMed Central

Maurand, R.; Jehl, X.; Kotekar-Patil, D.; Corna, A.; Bohuslavskyi, H.; Laviéville, R.; Hutin, L.; Barraud, S.; Vinet, M.; Sanquer, M.; De Franceschi, S.

2016-01-01

Silicon, the main constituent of microprocessor chips, is emerging as a promising material for the realization of future quantum processors. Leveraging its well-established complementary metal–oxide–semiconductor (CMOS) technology would be a clear asset to the development of scalable quantum computing architectures and to their co-integration with classical control hardware. Here we report a silicon quantum bit (qubit) device made with an industry-standard fabrication process. The device consists of a two-gate, p-type transistor with an undoped channel. At low temperature, the first gate defines a quantum dot encoding a hole spin qubit, the second one a quantum dot used for the qubit read-out. All electrical, two-axis control of the spin qubit is achieved by applying a phase-tunable microwave modulation to the first gate. The demonstrated qubit functionality in a basic transistor-like device constitutes a promising step towards the elaboration of scalable spin qubit geometries in a readily exploitable CMOS platform. PMID:27882926

Impact of VLSI/VHSIC on satellite on-board signal processing

NASA Astrophysics Data System (ADS)

Aanstoos, J. V.; Ruedger, W. H.; Snyder, W. E.; Kelly, W. L.

Forecasted improvements in IC fabrication techniques, such as the use of X-ray lithography, are expected to yield submicron circuit feature sizes within the decade of the 1980s. As dimensions decrease, reliability, cost, speed, power consumption and density improvements will be realized which have a significant impact on the capabilities of onboard spacecraft signal processing functions. This will in turn result in increases of the intelligence that may be deployed on spaceborne remote sensing platforms. Among programs oriented toward such goals are the silicon-based Very High Speed Integrated Circuit (VHSIC) researches sponsored by the U.S. Department of Defense, and efforts toward the development of GaAs devices which will compete with silicon VLSI technology for future applications. GaAs has an electron mobility which is five to six times that of silicon, and promises commensurate computation speed increases under low field conditions.

High-performance, low-voltage electroosmotic pumps with molecularly thin silicon nanomembranes

PubMed Central

Snyder, Jessica L.; Getpreecharsawas, Jirachai; Fang, David Z.; Gaborski, Thomas R.; Striemer, Christopher C.; Fauchet, Philippe M.; Borkholder, David A.; McGrath, James L.

2013-01-01

We have developed electroosmotic pumps (EOPs) fabricated from 15-nm-thick porous nanocrystalline silicon (pnc-Si) membranes. Ultrathin pnc-Si membranes enable high electroosmotic flow per unit voltage. We demonstrate that electroosmosis theory compares well with the observed pnc-Si flow rates. We attribute the high flow rates to high electrical fields present across the 15-nm span of the membrane. Surface modifications, such as plasma oxidation or silanization, can influence the electroosmotic flow rates through pnc-Si membranes by alteration of the zeta potential of the material. A prototype EOP that uses pnc-Si membranes and Ag/AgCl electrodes was shown to pump microliter per minute-range flow through a 0.5-mm-diameter capillary tubing with as low as 250 mV of applied voltage. This silicon-based platform enables straightforward integration of low-voltage, on-chip EOPs into portable microfluidic devices with low back pressures. PMID:24167263

A Plasmonic based Ultracompact Polarization Beam Splitter on Silicon-on-Insulator Waveguides

PubMed Central

Tan, Qilong; Huang, Xuguang; Zhou, Wen; Yang, Kun

2013-01-01

An ultracompact polarization beam splitter (PBS) is designed on silicon-on-insulator (SOI) platform based on the localized surface plasmons (LSPs) excited by particular polarization light. The device uses nanoscale silver cylinders as the polarization selection between two silicon waveguides of a directional coupler. The transverse-magnetic (TM) polarization light excites localized surface plasmons and is coupled into the cross port of the directional coupler with a low insert loss, while the transverse-electric (TE) polarization light is under restriction. The PBS has a coupling layer with 50 nm width and 1.1 μm length supporting broadband operation. The simulation calculations show that 22.06dB and 23.06dB of extinction ratios for the TE and TM polarizations were obtained, together with insertion losses of 0.09dB and 0.40dB. PMID:23856635

CMOS-Compatible Silicon Nanowire Field-Effect Transistor Biosensor: Technology Development toward Commercialization

PubMed Central

Wolfrum, Bernhard; Thierry, Benjamin

2018-01-01

Owing to their two-dimensional confinements, silicon nanowires display remarkable optical, magnetic, and electronic properties. Of special interest has been the development of advanced biosensing approaches based on the field effect associated with silicon nanowires (SiNWs). Recent advancements in top-down fabrication technologies have paved the way to large scale production of high density and quality arrays of SiNW field effect transistor (FETs), a critical step towards their integration in real-life biosensing applications. A key requirement toward the fulfilment of SiNW FETs’ promises in the bioanalytical field is their efficient integration within functional devices. Aiming to provide a comprehensive roadmap for the development of SiNW FET based sensing platforms, we critically review and discuss the key design and fabrication aspects relevant to their development and integration within complementary metal-oxide-semiconductor (CMOS) technology. PMID:29751688

Wafer scale formation of monocrystalline silicon-based Mie resonators via silicon-on-insulator dewetting.

PubMed

Abbarchi, Marco; Naffouti, Meher; Vial, Benjamin; Benkouider, Abdelmalek; Lermusiaux, Laurent; Favre, Luc; Ronda, Antoine; Bidault, Sébastien; Berbezier, Isabelle; Bonod, Nicolas

2014-11-25

Subwavelength-sized dielectric Mie resonators have recently emerged as a promising photonic platform, as they combine the advantages of dielectric microstructures and metallic nanoparticles supporting surface plasmon polaritons. Here, we report the capabilities of a dewetting-based process, independent of the sample size, to fabricate Si-based resonators over large scales starting from commercial silicon-on-insulator (SOI) substrates. Spontaneous dewetting is shown to allow the production of monocrystalline Mie-resonators that feature two resonant modes in the visible spectrum, as observed in confocal scattering spectroscopy. Homogeneous scattering responses and improved spatial ordering of the Si-based resonators are observed when dewetting is assisted by electron beam lithography. Finally, exploiting different thermal agglomeration regimes, we highlight the versatility of this technique, which, when assisted by focused ion beam nanopatterning, produces monocrystalline nanocrystals with ad hoc size, position, and organization in complex multimers.

Self-assembled single-crystal silicon circuits on plastic

PubMed Central

Stauth, Sean A.; Parviz, Babak A.

2006-01-01

We demonstrate the use of self-assembly for the integration of freestanding micrometer-scale components, including single-crystal, silicon field-effect transistors (FETs) and diffusion resistors, onto flexible plastic substrates. Preferential self-assembly of multiple microcomponent types onto a common platform is achieved through complementary shape recognition and aided by capillary, fluidic, and gravitational forces. We outline a microfabrication process that yields single-crystal, silicon FETs in a freestanding, powder-like collection for use with self-assembly. Demonstrations of self-assembled FETs on plastic include logic inverters and measured electron mobility of 592 cm2/V-s. Finally, we extend the self-assembly process to substrates each containing 10,000 binding sites and realize 97% self-assembly yield within 25 min for 100-μm-sized elements. High-yield self-assembly of micrometer-scale functional devices as outlined here provides a powerful approach for production of macroelectronic systems. PMID:16968780

Photonic crystal nanocavity assisted rejection ratio tunable notch microwave photonic filter

PubMed Central

Long, Yun; Xia, Jinsong; Zhang, Yong; Dong, Jianji; Wang, Jian

2017-01-01

Driven by the increasing demand on handing microwave signals with compact device, low power consumption, high efficiency and high reliability, it is highly desired to generate, distribute, and process microwave signals using photonic integrated circuits. Silicon photonics offers a promising platform facilitating ultracompact microwave photonic signal processing assisted by silicon nanophotonic devices. In this paper, we propose, theoretically analyze and experimentally demonstrate a simple scheme to realize ultracompact rejection ratio tunable notch microwave photonic filter (MPF) based on a silicon photonic crystal (PhC) nanocavity with fixed extinction ratio. Using a conventional modulation scheme with only a single phase modulator (PM), the rejection ratio of the presented MPF can be tuned from about 10 dB to beyond 60 dB. Moreover, the central frequency tunable operation in the high rejection ratio region is also demonstrated in the experiment. PMID:28067332

Quantum electromechanics on silicon nitride nanomembranes

PubMed Central

Fink, J. M.; Kalaee, M.; Pitanti, A.; Norte, R.; Heinzle, L.; Davanço, M.; Srinivasan, K.; Painter, O.

2016-01-01

Radiation pressure has recently been used to effectively couple the quantum motion of mechanical elements to the fields of optical or microwave light. Integration of all three degrees of freedom—mechanical, optical and microwave—would enable a quantum interconnect between microwave and optical quantum systems. We present a platform based on silicon nitride nanomembranes for integrating superconducting microwave circuits with planar acoustic and optical devices such as phononic and photonic crystals. Using planar capacitors with vacuum gaps of 60 nm and spiral inductor coils of micron pitch we realize microwave resonant circuits with large electromechanical coupling to planar acoustic structures of nanoscale dimensions and femtoFarad motional capacitance. Using this enhanced coupling, we demonstrate microwave backaction cooling of the 4.48 MHz mechanical resonance of a nanobeam to an occupancy as low as 0.32. These results indicate the viability of silicon nitride nanomembranes as an all-in-one substrate for quantum electro-opto-mechanical experiments. PMID:27484751

A CMOS silicon spin qubit

NASA Astrophysics Data System (ADS)

Maurand, R.; Jehl, X.; Kotekar-Patil, D.; Corna, A.; Bohuslavskyi, H.; Laviéville, R.; Hutin, L.; Barraud, S.; Vinet, M.; Sanquer, M.; de Franceschi, S.

2016-11-01

Silicon, the main constituent of microprocessor chips, is emerging as a promising material for the realization of future quantum processors. Leveraging its well-established complementary metal-oxide-semiconductor (CMOS) technology would be a clear asset to the development of scalable quantum computing architectures and to their co-integration with classical control hardware. Here we report a silicon quantum bit (qubit) device made with an industry-standard fabrication process. The device consists of a two-gate, p-type transistor with an undoped channel. At low temperature, the first gate defines a quantum dot encoding a hole spin qubit, the second one a quantum dot used for the qubit read-out. All electrical, two-axis control of the spin qubit is achieved by applying a phase-tunable microwave modulation to the first gate. The demonstrated qubit functionality in a basic transistor-like device constitutes a promising step towards the elaboration of scalable spin qubit geometries in a readily exploitable CMOS platform.

High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate

NASA Astrophysics Data System (ADS)

Witmer, Jeremy D.; Valery, Joseph A.; Arrangoiz-Arriola, Patricio; Sarabalis, Christopher J.; Hill, Jeff T.; Safavi-Naeini, Amir H.

2017-04-01

Future quantum networks, in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality (Q) factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical Q factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices.

Photonic crystal nanocavity assisted rejection ratio tunable notch microwave photonic filter

NASA Astrophysics Data System (ADS)

Long, Yun; Xia, Jinsong; Zhang, Yong; Dong, Jianji; Wang, Jian

2017-01-01

Driven by the increasing demand on handing microwave signals with compact device, low power consumption, high efficiency and high reliability, it is highly desired to generate, distribute, and process microwave signals using photonic integrated circuits. Silicon photonics offers a promising platform facilitating ultracompact microwave photonic signal processing assisted by silicon nanophotonic devices. In this paper, we propose, theoretically analyze and experimentally demonstrate a simple scheme to realize ultracompact rejection ratio tunable notch microwave photonic filter (MPF) based on a silicon photonic crystal (PhC) nanocavity with fixed extinction ratio. Using a conventional modulation scheme with only a single phase modulator (PM), the rejection ratio of the presented MPF can be tuned from about 10 dB to beyond 60 dB. Moreover, the central frequency tunable operation in the high rejection ratio region is also demonstrated in the experiment.

A CMOS silicon spin qubit.

PubMed

Maurand, R; Jehl, X; Kotekar-Patil, D; Corna, A; Bohuslavskyi, H; Laviéville, R; Hutin, L; Barraud, S; Vinet, M; Sanquer, M; De Franceschi, S

2016-11-24

Silicon, the main constituent of microprocessor chips, is emerging as a promising material for the realization of future quantum processors. Leveraging its well-established complementary metal-oxide-semiconductor (CMOS) technology would be a clear asset to the development of scalable quantum computing architectures and to their co-integration with classical control hardware. Here we report a silicon quantum bit (qubit) device made with an industry-standard fabrication process. The device consists of a two-gate, p-type transistor with an undoped channel. At low temperature, the first gate defines a quantum dot encoding a hole spin qubit, the second one a quantum dot used for the qubit read-out. All electrical, two-axis control of the spin qubit is achieved by applying a phase-tunable microwave modulation to the first gate. The demonstrated qubit functionality in a basic transistor-like device constitutes a promising step towards the elaboration of scalable spin qubit geometries in a readily exploitable CMOS platform.

Photonic crystal nanocavity assisted rejection ratio tunable notch microwave photonic filter.

PubMed

Long, Yun; Xia, Jinsong; Zhang, Yong; Dong, Jianji; Wang, Jian

2017-01-09

Driven by the increasing demand on handing microwave signals with compact device, low power consumption, high efficiency and high reliability, it is highly desired to generate, distribute, and process microwave signals using photonic integrated circuits. Silicon photonics offers a promising platform facilitating ultracompact microwave photonic signal processing assisted by silicon nanophotonic devices. In this paper, we propose, theoretically analyze and experimentally demonstrate a simple scheme to realize ultracompact rejection ratio tunable notch microwave photonic filter (MPF) based on a silicon photonic crystal (PhC) nanocavity with fixed extinction ratio. Using a conventional modulation scheme with only a single phase modulator (PM), the rejection ratio of the presented MPF can be tuned from about 10 dB to beyond 60 dB. Moreover, the central frequency tunable operation in the high rejection ratio region is also demonstrated in the experiment.

Quantum electromechanics on silicon nitride nanomembranes.

PubMed

Fink, J M; Kalaee, M; Pitanti, A; Norte, R; Heinzle, L; Davanço, M; Srinivasan, K; Painter, O

2016-08-03

Radiation pressure has recently been used to effectively couple the quantum motion of mechanical elements to the fields of optical or microwave light. Integration of all three degrees of freedom-mechanical, optical and microwave-would enable a quantum interconnect between microwave and optical quantum systems. We present a platform based on silicon nitride nanomembranes for integrating superconducting microwave circuits with planar acoustic and optical devices such as phononic and photonic crystals. Using planar capacitors with vacuum gaps of 60 nm and spiral inductor coils of micron pitch we realize microwave resonant circuits with large electromechanical coupling to planar acoustic structures of nanoscale dimensions and femtoFarad motional capacitance. Using this enhanced coupling, we demonstrate microwave backaction cooling of the 4.48 MHz mechanical resonance of a nanobeam to an occupancy as low as 0.32. These results indicate the viability of silicon nitride nanomembranes as an all-in-one substrate for quantum electro-opto-mechanical experiments.

A scalable silicon photonic chip-scale optical switch for high performance computing systems.

PubMed

Yu, Runxiang; Cheung, Stanley; Li, Yuliang; Okamoto, Katsunari; Proietti, Roberto; Yin, Yawei; Yoo, S J B

2013-12-30

This paper discusses the architecture and provides performance studies of a silicon photonic chip-scale optical switch for scalable interconnect network in high performance computing systems. The proposed switch exploits optical wavelength parallelism and wavelength routing characteristics of an Arrayed Waveguide Grating Router (AWGR) to allow contention resolution in the wavelength domain. Simulation results from a cycle-accurate network simulator indicate that, even with only two transmitter/receiver pairs per node, the switch exhibits lower end-to-end latency and higher throughput at high (>90%) input loads compared with electronic switches. On the device integration level, we propose to integrate all the components (ring modulators, photodetectors and AWGR) on a CMOS-compatible silicon photonic platform to ensure a compact, energy efficient and cost-effective device. We successfully demonstrate proof-of-concept routing functions on an 8 × 8 prototype fabricated using foundry services provided by OpSIS-IME.

CGS-MSFSS Project report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harvey-Collard, Patrick

2015-10-27

From January 2015 to July 2015, I was doing research at Sandia National Laboratories in Albuquerque, United States. My work there consisted of performing experimental measurements using Sandia’s unique silicon quantum computing platform. The project is about coupling donor spin quantum bits, or qubits, to quantum dots in a silicon nanostructure based on conventional microchip technology. During the project, I devised a new quantum state readout mechanism that allow better, longer lived measurement signals. The measurement (or readout) mechanism is key to any qubit architecture. Next, I was able to demonstrate a quantum manipulation of the two-electron spin states ofmore » the coupled donor and quantum dot system. This constitutes a breakthrough for donor spin qubits in silicon because it could enable larger systems consisting of many qubits. This project will lead to publications in scientific journals, presentations in international conferences, and generates exciting new opportunities for manipulating nature at the nanoscale.« less

Three-Dimensional Integration of Black Phosphorus Photodetector with Silicon Photonics and Nanoplasmonics.

PubMed

Chen, Che; Youngblood, Nathan; Peng, Ruoming; Yoo, Daehan; Mohr, Daniel A; Johnson, Timothy W; Oh, Sang-Hyun; Li, Mo

2017-02-08

We demonstrate the integration of a black phosphorus photodetector in a hybrid, three-dimensional architecture of silicon photonics and metallic nanoplasmonics structures. This integration approach combines the advantages of the low propagation loss of silicon waveguides, high-field confinement of a plasmonic nanogap, and the narrow bandgap of black phosphorus to achieve high responsivity for detection of telecom-band, near-infrared light. Benefiting from an ultrashort channel (∼60 nm) and near-field enhancement enabled by the nanogap structure, the photodetector shows an intrinsic responsivity as high as 10 A/W afforded by internal gain mechanisms, and a 3 dB roll-off frequency of 150 MHz. This device demonstrates a promising approach for on-chip integration of three distinctive photonic systems, which, as a generic platform, may lead to future nanophotonic applications for biosensing, nonlinear optics, and optical signal processing.

Evaluation of a Web-Based E-Learning Platform for Brief Motivational Interviewing by Nurses in Cardiovascular Care: A Pilot Study

PubMed Central

Cossette, Sylvie; Heppell, Sonia; Boyer, Louise; Mailhot, Tanya; Simard, Marie-Josée; Tanguay, Jean-Francois

2016-01-01

Background Brief motivational interviewing (MI) can contribute to reductions in morbidity and mortality related to coronary artery disease, through health behavior change. Brief MI, unlike more intensive interventions, was proposed to meet the needs of clinicians with little spare time. While the provision of face-to-face brief MI training on a large scale is complicated, Web-based e-learning is promising because of the flexibility it offers. Objective The primary objective of this pilot study was to examine the feasibility and acceptability of a Web-based e-learning platform for brief MI (MOTIV@CŒUR), which was evaluated by nurses in cardiovascular care. The secondary objective was to assess the preliminary effect of the training on nurses’ perceived brief MI skills and self-reported clinical use of brief MI. Methods We conducted a single-group, pre-post pilot study involving nurses working in a coronary care unit to evaluate MOTIV@CŒUR, which is a Web-based e-learning platform for brief MI, consisting of two sessions lasting 30 and 20 minutes. MOTIV@CŒUR covers 4 real-life clinical situations through role-modeling videos showing nurse-client interactions. A brief introduction to MI is followed by role playing, during which a nurse practitioner evaluates clients’ motivation to change and intervenes according to the principles of brief MI. The clinical situations target smoking, medication adherence, physical activity, and diet. Nurses were asked to complete both Web-based training sessions asynchronously within 20 days, which allowed assessment of the feasibility of the intervention. Data regarding acceptability and preliminary effects (perceived skills in brief MI, and self-reported clinical use of conviction and confidence interventions) were self-assessed through Web-based questionnaires 30 days (±5 days) after the first session. Results We enrolled 27 women and 4 men (mean age 37, SD 9 years) in March 2016. Of the 31 participants, 24 (77%, 95% CI 63%–91%) completed both sessions in ≤20 days. At 30 days, 28 of the 31 participants (90%) had completed at least one session. The training was rated as highly acceptable, with the highest scores observed for information quality (mean 6.26, SD 0.60; scale 0–7), perceived ease of use (mean 6.16, SD 0.78; scale 0–7), and system quality (mean 6.15, SD 0.58; scale 0–7). Posttraining scores for self-reported clinical use of confidence interventions were higher than pretraining scores (mean 34.72, SD 6.29 vs mean 31.48, SD 6.75, respectively; P=.03; scale 10–50). Other results were nonsignificant. Conclusions Brief MI training using a Web-based e-learning platform including role-modeling videos is both feasible and acceptable according to cardiovascular care nurses. Further research is required to evaluate the e-learning platform in a randomized controlled trial. Trial Registration International Standard Randomized Controlled Trial Number (ISRCTN): 16510888; http://www.isrctn.com/ISRCTN16510888 (Archived by WebCite at http://www.webcitation.org/6jf7dr7bx) PMID:27539960

Evaluation of a Web-Based E-Learning Platform for Brief Motivational Interviewing by Nurses in Cardiovascular Care: A Pilot Study.

PubMed

Fontaine, Guillaume; Cossette, Sylvie; Heppell, Sonia; Boyer, Louise; Mailhot, Tanya; Simard, Marie-Josée; Tanguay, Jean-Francois

2016-08-18

Brief motivational interviewing (MI) can contribute to reductions in morbidity and mortality related to coronary artery disease, through health behavior change. Brief MI, unlike more intensive interventions, was proposed to meet the needs of clinicians with little spare time. While the provision of face-to-face brief MI training on a large scale is complicated, Web-based e-learning is promising because of the flexibility it offers. The primary objective of this pilot study was to examine the feasibility and acceptability of a Web-based e-learning platform for brief MI (MOTIV@CŒUR), which was evaluated by nurses in cardiovascular care. The secondary objective was to assess the preliminary effect of the training on nurses' perceived brief MI skills and self-reported clinical use of brief MI. We conducted a single-group, pre-post pilot study involving nurses working in a coronary care unit to evaluate MOTIV@CŒUR, which is a Web-based e-learning platform for brief MI, consisting of two sessions lasting 30 and 20 minutes. MOTIV@CŒUR covers 4 real-life clinical situations through role-modeling videos showing nurse-client interactions. A brief introduction to MI is followed by role playing, during which a nurse practitioner evaluates clients' motivation to change and intervenes according to the principles of brief MI. The clinical situations target smoking, medication adherence, physical activity, and diet. Nurses were asked to complete both Web-based training sessions asynchronously within 20 days, which allowed assessment of the feasibility of the intervention. Data regarding acceptability and preliminary effects (perceived skills in brief MI, and self-reported clinical use of conviction and confidence interventions) were self-assessed through Web-based questionnaires 30 days (±5 days) after the first session. We enrolled 27 women and 4 men (mean age 37, SD 9 years) in March 2016. Of the 31 participants, 24 (77%, 95% CI 63%-91%) completed both sessions in ≤20 days. At 30 days, 28 of the 31 participants (90%) had completed at least one session. The training was rated as highly acceptable, with the highest scores observed for information quality (mean 6.26, SD 0.60; scale 0-7), perceived ease of use (mean 6.16, SD 0.78; scale 0-7), and system quality (mean 6.15, SD 0.58; scale 0-7). Posttraining scores for self-reported clinical use of confidence interventions were higher than pretraining scores (mean 34.72, SD 6.29 vs mean 31.48, SD 6.75, respectively; P=.03; scale 10-50). Other results were nonsignificant. Brief MI training using a Web-based e-learning platform including role-modeling videos is both feasible and acceptable according to cardiovascular care nurses. Further research is required to evaluate the e-learning platform in a randomized controlled trial. International Standard Randomized Controlled Trial Number (ISRCTN): 16510888; http://www.isrctn.com/ISRCTN16510888 (Archived by WebCite at http://www.webcitation.org/6jf7dr7bx).

Nanoporous Anodic Alumina: A Versatile Platform for Optical Biosensors

PubMed Central

Santos, Abel; Kumeria, Tushar; Losic, Dusan

2014-01-01

Nanoporous anodic alumina (NAA) has become one of the most promising nanomaterials in optical biosensing as a result of its unique physical and chemical properties. Many studies have demonstrated the outstanding capabilities of NAA for developing optical biosensors in combination with different optical techniques. These results reveal that NAA is a promising alternative to other widely explored nanoporous platforms, such as porous silicon. This review is aimed at reporting on the recent advances and current stage of development of NAA-based optical biosensing devices. The different optical detection techniques, principles and concepts are described in detail along with relevant examples of optical biosensing devices using NAA sensing platforms. Furthermore, we summarise the performance of these devices and provide a future perspective on this promising research field. PMID:28788678

National Built Environment Health Impact Assessment Model ...

EPA Pesticide Factsheets

Behavioral (activity, diet, social interaction) and exposure (air pollution, traffic injury, and noise) related health impacts of land use and transportation investment decisions are becoming better understood and quantified. Research has shown relationships between density, mix, street connectivity, access to parks, shops, transit, presence of sidewalks and bikeways, and healthy food with physical activity, obesity, cardiovascular disease, type II diabetes, and some mental health outcomes. This session demonstrates successful integration of health impact assessment into multiple scenario planning tool platforms. Detailed evidence on chronic disease and related costs associated with contrasting land use and transportation investments are built into a general-purpose module that can be accessed by multiple platforms. Funders, researchers, and end users of the tool will present a detailed description of the key elements of the approach, how it has been applied, and how will evolve. A critical focus will be placed on equity and social justice inherent within the assessment of health disparities that will be featured in the session. Health impacts of community design have significant cost benefit implications. Recent research is now extending relationships between community design features and chronic disease to health care costs. This session will demonstrate the recent application of this evidence on health impacts to the newly adopted Los Angeles Regional Transpo

Flexible Transient Optical Waveguides and Surface-Wave Biosensors Constructed from Monocrystalline Silicon.

PubMed

Bai, Wubin; Yang, Hongjun; Ma, Yinji; Chen, Hao; Shin, Jiho; Liu, Yonghao; Yang, Quansan; Kandela, Irawati; Liu, Zhonghe; Kang, Seung-Kyun; Wei, Chen; Haney, Chad R; Brikha, Anlil; Ge, Xiaochen; Feng, Xue; Braun, Paul V; Huang, Yonggang; Zhou, Weidong; Rogers, John A

2018-06-26

Optical technologies offer important capabilities in both biological research and clinical care. Recent interest is in implantable devices that provide intimate optical coupling to biological tissues for a finite time period and then undergo full bioresorption into benign products, thereby serving as temporary implants for diagnosis and/or therapy. The results presented here establish a silicon-based, bioresorbable photonic platform that relies on thin filaments of monocrystalline silicon encapsulated by polymers as flexible, transient optical waveguides for accurate light delivery and sensing at targeted sites in biological systems. Comprehensive studies of the mechanical and optical properties associated with bending and unfurling the waveguides from wafer-scale sources of materials establish general guidelines in fabrication and design. Monitoring biochemical species such as glucose and tracking physiological parameters such as oxygen saturation using near-infrared spectroscopic methods demonstrate modes of utility in biomedicine. These concepts provide versatile capabilities in biomedical diagnosis, therapy, deep-tissue imaging, and surgery, and suggest a broad range of opportunities for silicon photonics in bioresorbable technologies. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design of a broadband reciprocal optical diode in multimode silicon waveguide by partial depth etching

NASA Astrophysics Data System (ADS)

Zhu, Danfeng; Zhang, Jinqiannan; Ye, Han; Yu, Zhongyuan; Liu, Yumin

2018-07-01

We propose a design of reciprocal optical diode based on asymmetric spatial mode conversion in multimode silicon waveguide on the silicon-on-insulator platform. The design possesses large bandwidth, high contrast ratio and high fabrication tolerance. The forward even-to-odd mode conversion and backward blockade of even mode are achieved by partial depth etching in the functional region. Simulated by three-dimension finite-difference time-domain method, the forward transmission efficiency is about -2.05 dB while the backward transmission efficiency is only -22.68 dB, reaching a highest contrast ratio of 0.983 at the wavelength of 1550 nm. The operational bandwidth is up to 200 nm (from 1450 nm to 1650 nm) with contrast ratio higher than 0.911. The numerical analysis also demonstrates that the proposed optical diode possesses high tolerance for geometry parameter errors which may be introduced in fabrication. The design based on partial depth etching is compatible with CMOS process and is expected to contribute to the silicon-based all-optical circuits.

The flipped classroom for medical students.

PubMed

Morgan, Helen; McLean, Karen; Chapman, Chris; Fitzgerald, James; Yousuf, Aisha; Hammoud, Maya

2015-06-01

The objectives of this curricular innovation project were to implement a flipped classroom curriculum for the gynaecologic oncology topics of the obstetrics and gynaecology medical student clerkship, and to evaluate student satisfaction with the change. Four short online videos on the topics of endometrial hyperplasia, cervical dysplasia, evaluation of an adnexal mass, and ovarian cancer were created, and students were instructed to view them prior to a class-time active learning session. The Learning Activity Management System (lams) open-source online platform was used to create an active learning class-time activity that consisted of a coached discussion of cases. Student satisfaction with the two aspects of the flipped curriculum was obtained. In addition, lecture assessment for the gynaecologic oncology topics and aggregate student performance on the gynaecological oncology questions of the US National Board of Medical Examiners (NBME) Subject Examination were compared before and after implementation of the curriculum. Eighty-nine students rotated on the clerkship during the pilot period of analysis. Seventy-one students (80%) viewed the videos prior to the class session, and 84 (94%) attended the session. Student satisfaction was very high for both parts of the curriculum. There was no significant difference in aggregate student performance on the gynaecological oncology questions of the NBME Subject Examination. The flipped classroom curriculum demonstrates a promising platform for using technology to make better use of students' time Our implementation of the flipped classroom curriculum for the gynaecologic oncology topics successfully demonstrates a promising platform for using technology to make better use of our students' time, and for increasing their satisfaction with the necessary didactic learning of the clerkship. © 2015 John Wiley & Sons Ltd.

A Synthetic Self-Oscillating Vocal Fold Model Platform for Studying Augmentation Injection

PubMed Central

Murray, Preston R.; Thomson, Scott L.; Smith, Marshall E.

2013-01-01

Objective Design and evaluate a platform for studying the mechanical effects of augmentation injections using synthetic self-oscillating vocal fold models. Study Design Basic science. Methods Life-sized, synthetic, multi-layer, self-oscillating vocal fold models were created that simulated bowing via volumetric reduction of the body layer relative to that of a normal, unbowed model. Material properties of the layers were unchanged. Models with varying degrees of bowing were created and paired with normal models. Following initial acquisition of data (onset pressure, vibration frequency, flow rate, and high-speed image sequences), bowed models were injected with silicone that had material properties similar to those used in augmentation procedures. Three different silicone injection quantities were tested: sufficient to close the glottal gap, insufficient to close the glottal gap, and excess silicone to create convex bowing of the bowed model. The above-mentioned metrics were again taken and compared. Pre- and post-injection high-speed image sequences were acquired using a hemilarynx setup, from which medial surface dynamics were quantified. Results The models vibrated with mucosal wave-like motion and at onset pressures and frequencies typical of human phonation. The models successfully exhibited various degrees of bowing which were then mitigated by injecting filler material. The models showed general pre- to post-injection decreases in onset pressure, flow rate, and open quotient, and a corresponding increase in vibration frequency. Conclusion The model may be useful in further explorations of the mechanical consequences of augmentation injections. PMID:24476985

Silicon Valley as an Early Adopter for On-Demand Civil VTOL Operations

NASA Technical Reports Server (NTRS)

Antcliff, Kevin R.; Moore, Mark D.; Goodrich, Kenneth H.

2016-01-01

With high incomes, long commutes, severe ground geographic constraints, severe highway congestion during peak commute times, high housing costs, and near perfect year-round weather, the Silicon Valley is positioned to be an excellent early adopter market for emerging aviation On-Demand Mobility transportation solutions. Prior efforts have attempted to use existing aviation platforms (helicopters or General Aviation aircraft) with existing infrastructure solutions, or only investigated new vehicle platforms without understanding how to incorporate new vehicle types into existing built-up communities. Research has been performed with the objective of minimizing door-to-door time for "Hyper Commuters" (frequent, long-distance commuters) in the Silicon Valley through the development of new helipad infrastructure for ultra-low noise Vertical Takeoff and Landing (VTOL) aircraft. Current travel times for chosen city-pairs across urban and suburban commutes are compared to future mobility concepts that provide significantly higher utilization and productivity to yield competitive operating costs compared to existing transportation choices. Helipads are introduced near current modes of transportation and infrastructure for ease-of-access, and maximizing proximity. Strategies for both private and public infrastructure development are presented that require no new land purchase while minimizing community noise exposure. New VTOL concepts are introduced with cruise speeds of 200 mph, which yield a greater than three times improvement in overall door-to-door time when compared to current automobiles, and in some cases, improvements of up to 6 times lower trip times.

Feasibility and reliability of a virtual reality oculus platform to measure sensory integration for postural control in young adults.

PubMed

Lubetzky, Anat V; Kary, Erinn E; Harel, Daphna; Hujsak, Bryan; Perlin, Ken

2018-01-24

Using Unity for the Oculus Development-Kit 2, we have developed an affordable, portable virtual reality platform that targets the visuomotor domain, a missing link in current clinical assessments of postural control. Here, we describe the design and technical development as well as report its feasibility with regards to cybersickness and test-retest reliability in healthy young adults. Our virtual reality paradigm includes two functional scenes ('City' and 'Park') and four moving dots scenes. Twenty-one healthy young adults were tested twice, one to two weeks apart. They completed a simulator sickness questionnaire several times per session. Their postural sway response was recorded from a forceplate underneath their feet while standing on the floor, stability trainers, or a Both Sides Up (BOSU) ball. Sample entropy, postural displacement, velocity, and excursion were calculated and compared between sessions given the visual and surface conditions. Participants reported slight-to-moderate transient side effects. Intra-Class Correlation values mostly ranged from 0.5 to 0.7 for displacement and velocity, were above 0.5 (stability trainer conditions) and above 0.4 (floor mediolateral conditions) for sample entropy, and minimal for excursion. Our novel portable VR platform was found to be feasible and reliable in healthy young adults.

FIELD SCREENING METHODS FOR HAZARDOUS WASTES AND TOXIC CHEMICALS

EPA Science Inventory

The purpose of this document is to present the technical papers that were presented at the Second International Symposium on Field Screening Methods for Hazardous Wastes and Toxic Chemicals. ixty platform presentations were made and included in one of ten sessions: hemical sensor...

Engagement Scholarship Consortium Poster Awards

ERIC Educational Resources Information Center

Bargerstock, Burton A.

2012-01-01

The National Outreach Scholarship Conference has long provided a venue for the presentation of posters representing innovative research, effective practices, and impactful programs. In 2011, conference planners developed a series of measures focused on enriching the poster session as a platform for showcasing community-based scholarship and…

Balint 2.0: A virtual Balint group for doctors around the world.

PubMed

Nease, Donald E; Lichtenstein, Albert; Pinho-Costa, Luis; Hoedebecke, Kyle

2018-05-01

Objective Balint groups have shown promise in addressing clinician-patient relationships, clinician burnout, referral practices, and psychological mindedness. However, their traditional format of in-person sessions limits their ability to meet the needs of clinicians practicing in locations without trained Balint leaders. We report on a pilot of an international, internet-based Balint group in collaboration between the World Organization of Family Doctors regional Young Doctors Movements and the International Balint Federation. Method Balint 2.0 arose through interest of the Young Doctors Movements leadership, who approached the International Balint Federation for assistance. Initial discussions and some trialing of videoconference platforms led to monthly group meetings over the internet. Surveys evaluated each individual session as well as quarterly progress of the group. Survey items were borrowed from existing surveys in use by the American and German Balint Societies. Results Session surveys demonstrated the effectiveness of the videoconferencing platform for convening a Balint group, with a majority of participants expressing agreement with survey items evaluating each session. Quarterly survey responses were more positive reflecting agreement with outcomes seen from in-person Balint groups. Conclusions The Balint 2.0 pilot has demonstrated the ability of a Balint group to successfully convene over the internet and reach the common outcomes of a Balint group meeting in-person. The Young Doctors Movements and International Balint Federation plan to expand this work based on this successful pilot. We hope that others may also be able to build on this success with the result that Balint groups are available to clinicians in areas where they might not otherwise be accessible.

2004 Environmental Mutagen Society Annual Meeting - Genes, Mutations and Disease: The Environmental Connection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samson, Leona D.

2004-08-23

The Meeting consisted of 9 Symposia, 4 Keynote Lectures, 3 Platform Sessions and 4 Poster Sessions. In addition there were Breakfast Meetings for Special Interest Groups designed to inform attendees about the latest advances in environmental mutagenesis research. Several of the topics to be covered at this broad meeting will be of interest to the Department of Energy, Office of Science. The relevance of this meeting to the DOE derives from the fact that low dose radiation may represent one of the most significant sources of human mutations that are attributable to the environment. The EMS membership, and those whomore » attended the EMS Annual Meeting were interested in both chemical and radiation induced biological effects, such as cell death, mutation, teratogenesis, carcinogenesis and aging. These topics thate were presented at the 2004 EMS Annual meeting that were of clear interest to DOE include: human variation in cancer susceptibility, unusual mechanisms of mutation, germ and stem cell mutagenesis, recombination and the maintenance of genomic stability, multiple roles for DNA mismatch repair, DNA helicases, mutation, cancer and aging, Genome-wide transcriptional responses to environmental change, Telomeres and genomic stability: when ends don?t meet, systems biology approach to cell phenotypic decision processes, and the surprising biology of short RNAs. Poster and platform sessions addressed topics related to environmental mutagen exposure, DNA repair, mechanisms of mutagenesis, epidemiology, genomic and proteomics and bioinformatics. These sessions were designed to give student, postdocs and more junior scientists a chance to present their work.« less

Hybrid Tandem Solar Cells | Photovoltaic Research | NREL

Science.gov Websites

Hybrid Tandem Solar Cells Hybrid Tandem Solar Cells To achieve aggressive cost reductions in photovoltaics (PV) beyond the 6¢/kWh SunShot Initiative 2020 goal, module efficiency must be increased beyond on a silicon platform and that aim to provide viable prototypes for commercialization. PV Research

Reconfigurable SDM Switching Using Novel Silicon Photonic Integrated Circuit.

PubMed

Ding, Yunhong; Kamchevska, Valerija; Dalgaard, Kjeld; Ye, Feihong; Asif, Rameez; Gross, Simon; Withford, Michael J; Galili, Michael; Morioka, Toshio; Oxenløwe, Leif Katsuo

2016-12-21

Space division multiplexing using multicore fibers is becoming a more and more promising technology. In space-division multiplexing fiber network, the reconfigurable switch is one of the most critical components in network nodes. In this paper we for the first time demonstrate reconfigurable space-division multiplexing switching using silicon photonic integrated circuit, which is fabricated on a novel silicon-on-insulator platform with buried Al mirror. The silicon photonic integrated circuit is composed of a 7 × 7 switch and low loss grating coupler array based multicore fiber couplers. Thanks to the Al mirror, grating couplers with ultra-low coupling loss with optical multicore fibers is achieved. The lowest total insertion loss of the silicon integrated circuit is as low as 4.5 dB, with low crosstalk lower than -30 dB. Excellent performances in terms of low insertion loss and low crosstalk are obtained for the whole C-band. 1 Tb/s/core transmission over a 2-km 7-core fiber and space-division multiplexing switching is demonstrated successfully. Bit error rate performance below 10 -9 is obtained for all spatial channels with low power penalty. The proposed design can be easily upgraded to reconfigurable optical add/drop multiplexer capable of switching several multicore fibers.

Si photonics technology for future optical interconnection

NASA Astrophysics Data System (ADS)

Zheng, Xuezhe; Krishnamoorthy, Ashok V.

2011-12-01

Scaling of computing systems require ultra-efficient interconnects with large bandwidth density. Silicon photonics offers a disruptive solution with advantages in reach, energy efficiency and bandwidth density. We review our progress in developing building blocks for ultra-efficient WDM silicon photonic links. Employing microsolder based hybrid integration with low parasitics and high density, we optimize photonic devices on SOI platforms and VLSI circuits on more advanced bulk CMOS technology nodes independently. Progressively, we successfully demonstrated single channel hybrid silicon photonic transceivers at 5 Gbps and 10 Gbps, and 80 Gbps arrayed WDM silicon photonic transceiver using reverse biased depletion ring modulators and Ge waveguide photo detectors. Record-high energy efficiency of less than 100fJ/bit and 385 fJ/bit were achieved for the hybrid integrated transmitter and receiver, respectively. Waveguide grating based optical proximity couplers were developed with low loss and large optical bandwidth to enable multi-layer intra/inter-chip optical interconnects. Thermal engineering of WDM devices by selective substrate removal, together with WDM link using synthetic wavelength comb, we significantly improved the device tuning efficiency and reduced the tuning range. Using these innovative techniques, two orders of magnitude tuning power reduction was achieved. And tuning cost of only a few 10s of fJ/bit is expected for high data rate WDM silicon photonic links.

Reconfigurable SDM Switching Using Novel Silicon Photonic Integrated Circuit

NASA Astrophysics Data System (ADS)

Ding, Yunhong; Kamchevska, Valerija; Dalgaard, Kjeld; Ye, Feihong; Asif, Rameez; Gross, Simon; Withford, Michael J.; Galili, Michael; Morioka, Toshio; Oxenløwe, Leif Katsuo

2016-12-01

Space division multiplexing using multicore fibers is becoming a more and more promising technology. In space-division multiplexing fiber network, the reconfigurable switch is one of the most critical components in network nodes. In this paper we for the first time demonstrate reconfigurable space-division multiplexing switching using silicon photonic integrated circuit, which is fabricated on a novel silicon-on-insulator platform with buried Al mirror. The silicon photonic integrated circuit is composed of a 7 × 7 switch and low loss grating coupler array based multicore fiber couplers. Thanks to the Al mirror, grating couplers with ultra-low coupling loss with optical multicore fibers is achieved. The lowest total insertion loss of the silicon integrated circuit is as low as 4.5 dB, with low crosstalk lower than -30 dB. Excellent performances in terms of low insertion loss and low crosstalk are obtained for the whole C-band. 1 Tb/s/core transmission over a 2-km 7-core fiber and space-division multiplexing switching is demonstrated successfully. Bit error rate performance below 10-9 is obtained for all spatial channels with low power penalty. The proposed design can be easily upgraded to reconfigurable optical add/drop multiplexer capable of switching several multicore fibers.

Reconfigurable SDM Switching Using Novel Silicon Photonic Integrated Circuit

PubMed Central

Ding, Yunhong; Kamchevska, Valerija; Dalgaard, Kjeld; Ye, Feihong; Asif, Rameez; Gross, Simon; Withford, Michael J.; Galili, Michael; Morioka, Toshio; Oxenløwe, Leif Katsuo

2016-01-01

Space division multiplexing using multicore fibers is becoming a more and more promising technology. In space-division multiplexing fiber network, the reconfigurable switch is one of the most critical components in network nodes. In this paper we for the first time demonstrate reconfigurable space-division multiplexing switching using silicon photonic integrated circuit, which is fabricated on a novel silicon-on-insulator platform with buried Al mirror. The silicon photonic integrated circuit is composed of a 7 × 7 switch and low loss grating coupler array based multicore fiber couplers. Thanks to the Al mirror, grating couplers with ultra-low coupling loss with optical multicore fibers is achieved. The lowest total insertion loss of the silicon integrated circuit is as low as 4.5 dB, with low crosstalk lower than −30 dB. Excellent performances in terms of low insertion loss and low crosstalk are obtained for the whole C-band. 1 Tb/s/core transmission over a 2-km 7-core fiber and space-division multiplexing switching is demonstrated successfully. Bit error rate performance below 10−9 is obtained for all spatial channels with low power penalty. The proposed design can be easily upgraded to reconfigurable optical add/drop multiplexer capable of switching several multicore fibers. PMID:28000735

Jump-Down Performance Alterations after Space Flight

NASA Technical Reports Server (NTRS)

Reschke, M. F.; Kofman, I. S.; Cerisano, J. M.; Fisher, E. A.; Peters, B. T.; Miller, C. A.; Harm, D. L.; Bloomberg, J. J.

2011-01-01

INTRODUCTION: Successful jump performance requires functional coordination of visual, vestibular, and somatosensory systems, which are affected by prolonged exposure to microgravity. Astronauts returning from space flight exhibit impaired ability to coordinate effective landing strategies when jumping from a platform to the ground. This study compares jump strategies used by astronauts before and after flight, changes to those strategies within a test session, and recoveries in jump-down performance parameters across several postflight test sessions. These data were obtained as part of an ongoing interdisciplinary study (Functional Task Test, FTT) designed to evaluate both astronaut postflight functional performance and related physiological changes. METHODS: Seven astronauts from short-duration (Shuttle) and three from long-duration (International Space Station) flights performed 3 two-footed jumps from a platform 30 cm high onto a force plate that measured the ground reaction forces and center-of-pressure displacement from the landings. Neuromuscular activation data were collected from the medial gastrocnemius and anterior tibialis of both legs using surface electromyography electrodes. Two load cells in the platform measured the load exerted by each foot during the takeoff phase of the jump. Data were collected in 2 preflight sessions, on landing day (Shuttle only), and 1, 6, and 30 days after flight. RESULTS: Postural settling time was significantly increased on the first postflight test session and many of the astronauts tested were unable to maintain balance on their first jump landing but recovered by the third jump, showing a learning progression in which performance improvements could be attributed to adjustments in takeoff or landing strategy. Jump strategy changes were evident in reduced air time (time between takeoff and landing) and also in increased asymmetry in foot latencies on takeoff. CONCLUSIONS: The test results revealed significant decrements in astronauts abilities to maintain balance and achieve a postural stability upon landing from a jump early after flight. However, the jump landing adaptation process often begins after the first jump with full recovery of most performance parameters within days after space flight. As expected, performance of ISS astronauts on the first day after flight was similar to that of Shuttle crewmembers on landing day.

Phonon Networks with Silicon-Vacancy Centers in Diamond Waveguides

NASA Astrophysics Data System (ADS)

Lemonde, M.-A.; Meesala, S.; Sipahigil, A.; Schuetz, M. J. A.; Lukin, M. D.; Loncar, M.; Rabl, P.

2018-05-01

We propose and analyze a novel realization of a solid-state quantum network, where separated silicon-vacancy centers are coupled via the phonon modes of a quasi-one-dimensional diamond waveguide. In our approach, quantum states encoded in long-lived electronic spin states can be converted into propagating phonon wave packets and be reabsorbed efficiently by a distant defect center. Our analysis shows that under realistic conditions, this approach enables the implementation of high-fidelity, scalable quantum communication protocols within chip-scale spin-qubit networks. Apart from quantum information processing, this setup constitutes a novel waveguide QED platform, where strong-coupling effects between solid-state defects and individual propagating phonons can be explored at the quantum level.

Development of silicon carbide semiconductor devices for high temperature applications

NASA Technical Reports Server (NTRS)

Matus, Lawrence G.; Powell, J. Anthony; Petit, Jeremy B.

1991-01-01

The semiconducting properties of electronic grade silicon carbide crystals, such as wide energy bandgap, make it particularly attractive for high temperature applications. Applications for high temperature electronic devices include instrumentation for engines under development, engine control and condition monitoring systems, and power conditioning and control systems for space platforms and satellites. Discrete prototype SiC devices were fabricated and tested at elevated temperatures. Grown p-n junction diodes demonstrated very good rectification characteristics at 870 K. A depletion-mode metal-oxide-semiconductor field-effect transistor was also successfully fabricated and tested at 770 K. While optimization of SiC fabrication processes remain, it is believed that SiC is an enabling high temperature electronic technology.

Mechanics of finger-tip electronics

NASA Astrophysics Data System (ADS)

Su, Yewang; Li, Rui; Cheng, Huanyu; Ying, Ming; Bonifas, Andrew P.; Hwang, Keh-Chih; Rogers, John A.; Huang, Yonggang

2013-10-01

Tactile sensors and electrotactile stimulators can provide important links between humans and virtual environments, through the sensation of touch. Soft materials, such as low modulus silicones, are attractive as platforms and support matrices for arrays sensors and actuators that laminate directly onto the fingertips. Analytic models for the mechanics of three dimensional, form-fitting finger cuffs based on such designs are presented here, along with quantitative validation using the finite element method. The results indicate that the maximum strains in the silicone and the embedded devices are inversely proportional to the square root of radius of curvature of the cuff. These and other findings can be useful in formulating designs for these and related classes of body-worn, three dimensional devices.

Optimization of silicon waveguides for gas detection application at mid-IR wavelengths

NASA Astrophysics Data System (ADS)

Butt, M. A.; Kozlova, E. S.

2018-04-01

There are several trace gases such as N2O, CO, CO2, NO, H2O, NO2, NH3, CH4 etc. which have their absorption peaks in Mid-IR spectrum These gases strongly absorb in the mid-IR > 2.5 μm spectral region due to their fundamental rotational and vibrational transitions. In this work, we modelled and optimized three different kinds of waveguides such as rib, strip and slot based on silicon platform to obtain maximum evanescent field ratio. These waveguides are designed at 3.39 μm and 4.67 μm which correspond to the absorption line of methane (CH4) and carbon monoxide (CO) respectively.

Porous Silicon Structures as Optical Gas Sensors

PubMed Central

Levitsky, Igor A.

2015-01-01

We present a short review of recent progress in the field of optical gas sensors based on porous silicon (PSi) and PSi composites, which are separate from PSi optochemical and biological sensors for a liquid medium. Different periodical and nonperiodical PSi photonic structures (bares, modified by functional groups or infiltrated with sensory polymers) are described for gas sensing with an emphasis on the device specificity, sensitivity and stability to the environment. Special attention is paid to multiparametric sensing and sensor array platforms as effective trends for the improvement of analyte classification and quantification. Mechanisms of gas physical and chemical sorption inside PSi mesopores and pores of PSi functional composites are discussed. PMID:26287199

A review of materials engineering in silicon-based optical fibres

NASA Astrophysics Data System (ADS)

Healy, Noel; Gibson, Ursula; Peacock, Anna C.

2018-02-01

Semiconductor optical fibre technologies have grown rapidly in the last decade and there are now a range of production and post-processing techniques that allow for a vast degree of control over the core material's optoelectronic properties. These methodologies and the unique optical fibre geometry provide an exciting platform for materials engineering and fibres can now be produced with single crystal cores, low optical losses, tunable strain, and inscribable phase composition. This review discusses the state-of-the-art regarding the production of silicon optical fibres in amorphous and crystalline form and then looks at the post-processing techniques and the improved material quality and new functionality that they afford.

Phonon Networks with Silicon-Vacancy Centers in Diamond Waveguides.

PubMed

Lemonde, M-A; Meesala, S; Sipahigil, A; Schuetz, M J A; Lukin, M D; Loncar, M; Rabl, P

2018-05-25

We propose and analyze a novel realization of a solid-state quantum network, where separated silicon-vacancy centers are coupled via the phonon modes of a quasi-one-dimensional diamond waveguide. In our approach, quantum states encoded in long-lived electronic spin states can be converted into propagating phonon wave packets and be reabsorbed efficiently by a distant defect center. Our analysis shows that under realistic conditions, this approach enables the implementation of high-fidelity, scalable quantum communication protocols within chip-scale spin-qubit networks. Apart from quantum information processing, this setup constitutes a novel waveguide QED platform, where strong-coupling effects between solid-state defects and individual propagating phonons can be explored at the quantum level.

Hybrid integration of VCSELs onto a silicon photonic platform for biosensing application

NASA Astrophysics Data System (ADS)

Lu, Huihui; Lee, Jun Su; Zhao, Yan; Cardile, Paolo; Daly, Aidan; Carroll, Lee; O'Brien, Peter

2017-02-01

This paper presents a technology of hybrid integration vertical cavity surface emitting lasers (VCSELs) directly on silicon photonics chip. By controlling the reflow of the solder balls used for electrical and mechanical bonding, the VCSELs were bonded at 10 degree to achieve the optimum angle-of-incidence to the planar grating coupler through vision based flip-chip techniques. The 1 dB discrepancy between optical loss values of flip-chip passive assembly and active alignment confirmed that the general purpose of the flip-chip design concept is achieved. This hybrid approach of integrating a miniaturized light source on chip opens the possibly of highly compact sensor system, which enable future portable and wearable diagnostics devices.

Roadmap on silicon photonics

NASA Astrophysics Data System (ADS)

Thomson, David; Zilkie, Aaron; Bowers, John E.; Komljenovic, Tin; Reed, Graham T.; Vivien, Laurent; Marris-Morini, Delphine; Cassan, Eric; Virot, Léopold; Fédéli, Jean-Marc; Hartmann, Jean-Michel; Schmid, Jens H.; Xu, Dan-Xia; Boeuf, Frédéric; O'Brien, Peter; Mashanovich, Goran Z.; Nedeljkovic, M.

2016-07-01

Silicon photonics research can be dated back to the 1980s. However, the previous decade has witnessed an explosive growth in the field. Silicon photonics is a disruptive technology that is poised to revolutionize a number of application areas, for example, data centers, high-performance computing and sensing. The key driving force behind silicon photonics is the ability to use CMOS-like fabrication resulting in high-volume production at low cost. This is a key enabling factor for bringing photonics to a range of technology areas where the costs of implementation using traditional photonic elements such as those used for the telecommunications industry would be prohibitive. Silicon does however have a number of shortcomings as a photonic material. In its basic form it is not an ideal material in which to produce light sources, optical modulators or photodetectors for example. A wealth of research effort from both academia and industry in recent years has fueled the demonstration of multiple solutions to these and other problems, and as time progresses new approaches are increasingly being conceived. It is clear that silicon photonics has a bright future. However, with a growing number of approaches available, what will the silicon photonic integrated circuit of the future look like? This roadmap on silicon photonics delves into the different technology and application areas of the field giving an insight into the state-of-the-art as well as current and future challenges faced by researchers worldwide. Contributions authored by experts from both industry and academia provide an overview and outlook for the silicon waveguide platform, optical sources, optical modulators, photodetectors, integration approaches, packaging, applications of silicon photonics and approaches required to satisfy applications at mid-infrared wavelengths. Advances in science and technology required to meet challenges faced by the field in each of these areas are also addressed together with predictions of where the field is destined to reach.

A Platform for Scalable Satellite and Geospatial Data Analysis

NASA Astrophysics Data System (ADS)

Beneke, C. M.; Skillman, S.; Warren, M. S.; Kelton, T.; Brumby, S. P.; Chartrand, R.; Mathis, M.

2017-12-01

At Descartes Labs, we use the commercial cloud to run global-scale machine learning applications over satellite imagery. We have processed over 5 Petabytes of public and commercial satellite imagery, including the full Landsat and Sentinel archives. By combining open-source tools with a FUSE-based filesystem for cloud storage, we have enabled a scalable compute platform that has demonstrated reading over 200 GB/s of satellite imagery into cloud compute nodes. In one application, we generated global 15m Landsat-8, 20m Sentinel-1, and 10m Sentinel-2 composites from 15 trillion pixels, using over 10,000 CPUs. We recently created a public open-source Python client library that can be used to query and access preprocessed public satellite imagery from within our platform, and made this platform available to researchers for non-commercial projects. In this session, we will describe how you can use the Descartes Labs Platform for rapid prototyping and scaling of geospatial analyses and demonstrate examples in land cover classification.

DNA-Mediated Patterning of Single Quantum Dot Nanoarrays: A Reusable Platform for Single-Molecule Control

NASA Astrophysics Data System (ADS)

Huang, Da; Freeley, Mark; Palma, Matteo

2017-03-01

We present a facile strategy of general applicability for the assembly of individual nanoscale moieties in array configurations with single-molecule control. Combining the programming ability of DNA as a scaffolding material with a one-step lithographic process, we demonstrate the patterning of single quantum dots (QDs) at predefined locations on silicon and transparent glass surfaces: as proof of concept, clusters of either one, two, or three QDs were assembled in highly uniform arrays with a 60 nm interdot spacing within each cluster. Notably, the platform developed is reusable after a simple cleaning process and can be designed to exhibit different geometrical arrangements.

TM grating coupler on low-loss LPCVD based Si3N4 waveguide platform

NASA Astrophysics Data System (ADS)

Dabos, G.; Manolis, A.; Giesecke, A. L.; Porschatis, C.; Chmielak, B.; Wahlbrink, T.; Pleros, N.; Tsiokos, D.

2017-12-01

We demonstrate, for the first time to our knowledge, a fully etched TM grating coupler for low-loss Low-Pressure-Chemical-Vapor-Deposition (LPCVD) based silicon nitride platform with a coupling loss of 6.5 dB at 1541 nm and a 1 dB bandwidth of 55 nm, addressing applications where TM polarization is a pre-requisite. The proposed GC and the 360 nm × 800 nm strip based Si3N4 waveguides have been fabricated by optical projection lithography using an i-line stepper tool enabling low-cost and mass manufacturing of photonic-integrated-circuits.

A III-V nanowire channel on silicon for high-performance vertical transistors.

PubMed

Tomioka, Katsuhiro; Yoshimura, Masatoshi; Fukui, Takashi

2012-08-09

Silicon transistors are expected to have new gate architectures, channel materials and switching mechanisms in ten years' time. The trend in transistor scaling has already led to a change in gate structure from two dimensions to three, used in fin field-effect transistors, to avoid problems inherent in miniaturization such as high off-state leakage current and the short-channel effect. At present, planar and fin architectures using III-V materials, specifically InGaAs, are being explored as alternative fast channels on silicon because of their high electron mobility and high-quality interface with gate dielectrics. The idea of surrounding-gate transistors, in which the gate is wrapped around a nanowire channel to provide the best possible electrostatic gate control, using InGaAs channels on silicon, however, has been less well investigated because of difficulties in integrating free-standing InGaAs nanostructures on silicon. Here we report the position-controlled growth of vertical InGaAs nanowires on silicon without any buffering technique and demonstrate surrounding-gate transistors using InGaAs nanowires and InGaAs/InP/InAlAs/InGaAs core-multishell nanowires as channels. Surrounding-gate transistors using core-multishell nanowire channels with a six-sided, high-electron-mobility transistor structure greatly enhance the on-state current and transconductance while keeping good gate controllability. These devices provide a route to making vertically oriented transistors for the next generation of field-effect transistors and may be useful as building blocks for wireless networks on silicon platforms.

Design of a New Ultracompact Resonant Plasmonic Multi-Analyte Label-Free Biosensing Platform

PubMed Central

De Palo, Maripina; Ciminelli, Caterina

2017-01-01

In this paper, we report on the design of a bio-multisensing platform for the selective label-free detection of protein biomarkers, carried out through a 3D numerical algorithm. The platform includes a number of biosensors, each of them is based on a plasmonic nanocavity, consisting of a periodic metal structure to be deposited on a silicon oxide substrate. Light is strongly confined in a region with extremely small size (=1.57 μm2), to enhance the light-matter interaction. A surface sensitivity Ss = 1.8 nm/nm has been calculated together with a detection limit of 128 pg/mm2. Such performance, together with the extremely small footprint, allow the integration of several devices on a single chip to realize extremely compact lab-on-chip microsystems. In addition, each sensing element of the platform has a good chemical stability that is guaranteed by the selection of gold for its fabrication. PMID:28783075

GOLIAH: A Gaming Platform for Home-Based Intervention in Autism – Principles and Design

PubMed Central

Bono, Valentina; Narzisi, Antonio; Jouen, Anne-Lise; Tilmont, Elodie; Hommel, Stephane; Jamal, Wasifa; Xavier, Jean; Billeci, Lucia; Maharatna, Koushik; Wald, Mike; Chetouani, Mohamed; Cohen, David; Muratori, Filippo

2016-01-01

Children with Autism need intensive intervention and this is challenging in terms of manpower, costs, and time. Advances in Information Communication Technology and computer gaming may help in this respect by creating a nomadically deployable closed-loop intervention system involving the child and active participation of parents and therapists. An automated serious gaming platform enabling intensive intervention in nomadic settings has been developed by mapping two pivotal skills in autism spectrum disorder: Imitation and Joint Attention (JA). Eleven games – seven Imitations and four JA – were derived from the Early Start Denver Model. The games involved application of visual and audio stimuli with multiple difficulty levels and a wide variety of tasks and actions pertaining to the Imitation and JA. The platform runs on mobile devices and allows the therapist to (1) characterize the child’s initial difficulties/strengths, ensuring tailored and adapted intervention by choosing appropriate games and (2) investigate and track the temporal evolution of the child’s progress through a set of automatically extracted quantitative performance metrics. The platform allows the therapist to change the game or its difficulty levels during the intervention depending on the child’s progress. Performance of the platform was assessed in a 3-month open trial with 10 children with autism (Trial ID: NCT02560415, Clinicaltrials.gov). The children and the parents participated in 80% of the sessions both at home (77.5%) and at the hospital (90%). All children went through all the games but, given the diversity of the games and the heterogeneity of children profiles and abilities, for a given game the number of sessions dedicated to the game varied and could be tailored through automatic scoring. Parents (N = 10) highlighted enhancement in the child’s concentration, flexibility, and self-esteem in 78, 89, and 44% of the cases, respectively, and 56% observed an enhanced parents–child relationship. This pilot study shows the feasibility of using the developed gaming platform for home-based intensive intervention. However, the overall capability of the platform in delivering intervention needs to be assessed in a bigger open trial. PMID:27199777

GOLIAH: A Gaming Platform for Home-Based Intervention in Autism - Principles and Design.

PubMed

Bono, Valentina; Narzisi, Antonio; Jouen, Anne-Lise; Tilmont, Elodie; Hommel, Stephane; Jamal, Wasifa; Xavier, Jean; Billeci, Lucia; Maharatna, Koushik; Wald, Mike; Chetouani, Mohamed; Cohen, David; Muratori, Filippo

2016-01-01

Children with Autism need intensive intervention and this is challenging in terms of manpower, costs, and time. Advances in Information Communication Technology and computer gaming may help in this respect by creating a nomadically deployable closed-loop intervention system involving the child and active participation of parents and therapists. An automated serious gaming platform enabling intensive intervention in nomadic settings has been developed by mapping two pivotal skills in autism spectrum disorder: Imitation and Joint Attention (JA). Eleven games - seven Imitations and four JA - were derived from the Early Start Denver Model. The games involved application of visual and audio stimuli with multiple difficulty levels and a wide variety of tasks and actions pertaining to the Imitation and JA. The platform runs on mobile devices and allows the therapist to (1) characterize the child's initial difficulties/strengths, ensuring tailored and adapted intervention by choosing appropriate games and (2) investigate and track the temporal evolution of the child's progress through a set of automatically extracted quantitative performance metrics. The platform allows the therapist to change the game or its difficulty levels during the intervention depending on the child's progress. Performance of the platform was assessed in a 3-month open trial with 10 children with autism (Trial ID: NCT02560415, Clinicaltrials.gov). The children and the parents participated in 80% of the sessions both at home (77.5%) and at the hospital (90%). All children went through all the games but, given the diversity of the games and the heterogeneity of children profiles and abilities, for a given game the number of sessions dedicated to the game varied and could be tailored through automatic scoring. Parents (N = 10) highlighted enhancement in the child's concentration, flexibility, and self-esteem in 78, 89, and 44% of the cases, respectively, and 56% observed an enhanced parents-child relationship. This pilot study shows the feasibility of using the developed gaming platform for home-based intensive intervention. However, the overall capability of the platform in delivering intervention needs to be assessed in a bigger open trial.

Where's My Data - WMD

NASA Technical Reports Server (NTRS)

Quach, William L.; Sesplaukis, Tadas; Owen-Mankovich, Kyran J.; Nakamura, Lori L.

2012-01-01

WMD provides a centralized interface to access data stored in the Mission Data Processing and Control System (MPCS) GDS (Ground Data Systems) databases during MSL (Mars Science Laboratory) Testbeds and ATLO (Assembly, Test, and Launch Operations) test sessions. The MSL project organizes its data based on venue (Testbed, ATLO, Ops), with each venue's data stored on a separate database, making it cumbersome for users to access data across the various venues. WMD allows sessions to be retrieved through a Web-based search using several criteria: host name, session start date, or session ID number. Sessions matching the search criteria will be displayed and users can then select a session to obtain and analyze the associated data. The uniqueness of this software comes from its collection of data retrieval and analysis features provided through a single interface. This allows users to obtain their data and perform the necessary analysis without having to worry about where and how to get the data, which may be stored in various locations. Additionally, this software is a Web application that only requires a standard browser without additional plug-ins, providing a cross-platform, lightweight solution for users to retrieve and analyze their data. This software solves the problem of efficiently and easily finding and retrieving data from thousands of MSL Testbed and ATLO sessions. WMD allows the user to retrieve their session in as little as one mouse click, and then to quickly retrieve additional data associated with the session.

Snaps, Selfies, and Shares: How Three Popular Social Media Platforms Contribute to the Sociocultural Model of Disordered Eating Among Young Women.

PubMed

Saunders, Jessica F; Eaton, Asia A

2018-06-01

The current study aimed to integrate and test the sociocultural model of disordered eating with theories explaining the impact of mass media on the development of disordered eating for users of three popular social networking platforms. Young women social networking site (SNS) users (age 18-24) who had never received an eating disorder diagnosis (N = 637) completed questions capturing their SNS gratifications and usage, body surveillance, social comparisons, body dissatisfaction, and eating pathology. Measures were administered in one online session. Model relationships were similar across users of all three SNS platforms: Facebook, Instagram, and Snapchat. Users of all platforms demonstrated a significant positive relationship between upward comparisons and disordered eating outcomes, and between body surveillance and disordered eating outcomes, although differences between models did emerge. Empirical findings support extending the sociocultural model of disordered eating to include SNS uses and gratifications.

Outcomes of Fundamentals of Laparoscopic Surgery (FLS) mastery training standards applied to an ergonomically different, lower cost platform.

PubMed

Placek, Sarah B; Franklin, Brenton R; Haviland, Sarah M; Wagner, Mercy D; O'Donnell, Mary T; Cryer, Chad T; Trinca, Kristen D; Silverman, Elliott; Matthew Ritter, E

2017-06-01

Using previously established mastery learning standards, this study compares outcomes of training on standard FLS (FLS) equipment with training on an ergonomically different (ED-FLS), but more portable, lower cost platform. Subjects completed a pre-training FLS skills test on the standard platform and were then randomized to train on the FLS training platform (n = 20) or the ED-FLS platform (n = 19). A post-training FLS skills test was administered to both groups on the standard FLS platform. Group performance on the pretest was similar. Fifty percent of FLS and 32 % of ED-FLS subjects completed the entire curriculum. 100 % of subjects completing the curriculum achieved passing scores on the post-training test. There was no statistically discernible difference in scores on the final FLS exam (FLS 93.4, ED-FLS 93.3, p = 0.98) or training sessions required to complete the curriculum (FLS 7.4, ED-FLS 9.8, p = 0.13). These results show that when applying mastery learning theory to an ergonomically different platform, skill transfer occurs at a high level and prepares subjects to pass the standard FLS skills test.

Collaborative Control of Media Playbacks in SCDNs

ERIC Educational Resources Information Center

Fortino, Giancarlo; Russo, Wilma; Palau, Carlos E.

2006-01-01

In this paper we present a CDN-based system, namely the COMODIN system, which is a media on-demand platform for synchronous cooperative work which supports an explicitly-formed cooperative group of distributed users with the following integrated functionalities: request of an archived multimedia session, sharing of its playback, and collaboration…

PLATFORM SESSION "IMMUNOTOXICOLOGY", SOCIETY OF TOXICOLOGY 45TH ANNUAL MEETING, MARCH 5-9, 2006, SAN DIEGO, CA

EPA Science Inventory

For many years the primary endpoints for evaluating the toxicity of xenobiotics were carcinogenicity and mutagenicity. However, it gradually became apparent that exposure to chemicals at levels lower than those shown to be directly carcinogenic may negatively impact other facets...

A Design Methodology for Complex (E)-Learning. Innovative Session.

ERIC Educational Resources Information Center

Bastiaens, Theo; van Merrienboer, Jeroen; Hoogveld, Bert

Human resource development (HRD) specialists are searching for instructional design models that accommodate e-learning platforms. Van Merrienboer proposed the four-component instructional design model (4C/ID model) for competency-based education. The model's basic message is that well-designed learning environments can always be described in terms…

Fabrication of Pop-up Detector Arrays on Si Wafers

NASA Technical Reports Server (NTRS)

Li, Mary J.; Allen, Christine A.; Gordon, Scott A.; Kuhn, Jonathan L.; Mott, David B.; Stahle, Caroline K.; Wang, Liqin L.

1999-01-01

High sensitivity is a basic requirement for a new generation of thermal detectors. To meet the requirement, close-packed, two-dimensional silicon detector arrays have been developed in NASA Goddard Space Flight Center. The goal of the task is to fabricate detector arrays configured with thermal detectors such as infrared bolometers and x-ray calorimeters to use in space fliGht missions. This paper focuses on the fabrication and the mechanical testing of detector arrays in a 0.2 mm pixel size, the smallest pop-up detectors being developed so far. These array structures, nicknamed "PUDS" for "Pop-Up Detectors", are fabricated on I pm thick, single-crystal, silicon membranes. Their designs have been refined so we can utilize the flexibility of thin silicon films by actually folding the silicon membranes to 90 degrees in order to obtain close-packed two-dimensional arrays. The PUD elements consist of a detector platform and two legs for mechanical support while also serving as electrical and thermal paths. Torsion bars and cantilevers connecting the detector platform to the legs provide additional flexures for strain relief. Using micro-electromechanical structure (MEMS) fabrication techniques, including photolithography, anisotropic chemical etching, reactive-ion etching, and laser dicing, we have fabricated PLTD detector arrays of fourteen designs with a variation of four parameters including cantilever length, torsion bar length and width, and leg length. Folding tests were conducted to test mechanical stress distribution for the array structures. We obtained folding yields and selected optimum design parameters to reach minimal stress levels. Computer simulation was also employed to verify mechanical behaviors of PUDs in the folding process. In addition, scanning electron microscopy was utilized to examine the flatness of detectors and the alignment of detector pixels in arrays. The fabrication of thermistors and heaters on the pop-up detectors is under way, preparing us for the next step of the experiment, the thermal test.

The APECS Virtual Poster Session: a virtual platform for science communication and discussion

NASA Astrophysics Data System (ADS)

Renner, A.; Jochum, K.; Jullion, L.; Pavlov, A.; Liggett, D.; Fugmann, G.; Baeseman, J. L.; Apecs Virtual Poster Session Working Group, T.

2011-12-01

The Virtual Poster Session (VPS) of the Association of Polar Early Career Scientists (APECS) was developed by early career scientists as an online tool for communicating and discussing science and research beyond the four walls of a conference venue. Poster sessions often are the backbone of a conference where especially early career scientists get a chance to communicate their research, discuss ideas, data, and scientific problems with their peers and senior scientists. There, they can hone their 'elevator pitch', discussion skills and presentation skills. APECS has taken the poster session one step further and created the VPS - the same idea but independent from conferences, travel, and location. All that is needed is a computer with internet access. Instead of letting their posters collect dust on the computer's hard drive, scientists can now upload them to the APECS website. There, others have the continuous opportunity to comment, give feedback and discuss the work. Currently, about 200 posters are accessible contributed by authors and co-authors from 34 countries. Since January 2010, researchers can discuss their poster with a broad international audience including fellow researchers, community members, potential colleagues and collaborators, policy makers and educators during monthly conference calls via an internet platform. Recordings of the calls are available online afterwards. Calls so far have included topical sessions on e.g. marine biology, glaciology, or social sciences, and interdisciplinary calls on Arctic sciences or polar research activities in a specific country, e.g. India or Romania. They attracted audiences of scientists at all career stages and from all continents, with on average about 15 persons participating per call. Online tools like the VPS open up new ways for creating collaborations and new research ideas and sharing different methodologies for future projects, pushing aside the boundaries of countries and nations, conferences, offices, and disciplines, and provide early career scientists with easily accessible training opportunities for their communication and outreach skills, independent of their location and funding situation.

Supervised versus unsupervised technology-based levodopa monitoring in Parkinson's disease: an intrasubject comparison.

PubMed

Lopane, Giovanna; Mellone, Sabato; Corzani, Mattia; Chiari, Lorenzo; Cortelli, Pietro; Calandra-Buonaura, Giovanna; Contin, Manuela

2018-06-01

We aimed to assess the intrasubject reproducibility of a technology-based levodopa (LD) therapeutic monitoring protocol administered in supervised versus unsupervised conditions in patients with Parkinson's disease (PD). The study design was pilot, intrasubject, single center, open and prospective. Twenty patients were recruited. Patients performed a standardized monitoring protocol instrumented by an ad hoc embedded platform after their usual first morning LD dose in two different randomized ambulatory sessions: one under a physician's supervision, the other self-administered. The protocol is made up of serial motor and non-motor tests, including alternate finger tapping, Timed Up and Go test, and measurement of blood pressure. Primary motor outcomes included comparisons of intrasubject LD subacute motor response patterns over the 3-h test in the two experimental conditions. Secondary outcomes were the number of intrasession serial test repetitions due to technical or handling errors and patients' satisfaction with the unsupervised LD monitoring protocol. Intrasubject LD motor response patterns were concordant between the two study sessions in all patients but one. Platform handling problems averaged 4% of total planned serial tests for both sessions. Ninety-five percent of patients were satisfied with the self-administered LD monitoring protocol. To our knowledge, this study is the first to explore the potential of unsupervised technology-based objective motor and non-motor tasks to monitor subacute LD dosing effects in PD patients. The results are promising for future telemedicine applications.

Photonic crystal ring resonator-based four-channel dense wavelength division multiplexing demultiplexer on silicon on insulator platform: design and analysis

NASA Astrophysics Data System (ADS)

Sreenivasulu, Tupakula; Bhowmick, Kaustav; Samad, Shafeek A.; Yadunath, Thamerassery Illam R.; Badrinarayana, Tarimala; Hegde, Gopalkrishna; Srinivas, Talabattula

2018-04-01

A micro/nanofabrication feasible compact photonic crystal (PC) ring-resonator-based channel drop filter has been designed and analyzed for operation in C and L bands of communication window. The four-channel demultiplexer consists of ring resonators of holes in two-dimensional PC slab. The proposed assembly design of dense wavelength division multiplexing setup is shown to achieve optimal quality factor, without altering the lattice parameters or resonator size or inclusion of scattering holes. Transmission characteristics are analyzed using the three-dimensional finite-difference time-domain simulation approach. The radiation loss of the ring resonator was minimized by forced cancelation of radiation fields by fine-tuning the air holes inside the ring resonator. An average cross talk of -34 dB has been achieved between the adjacent channels maintaining an average quality factor of 5000. Demultiplexing is achieved by engineering only the air holes inside the ring, which makes it a simple and tolerant design from the fabrication perspective. Also, the device footprint of 500 μm2 on silicon on insulator platform makes it easy to fabricate the device using e-beam lithography technique.

Toward Intelligent Synthetic Neural Circuits: Directing and Accelerating Neuron Cell Growth by Self-Rolled-Up Silicon Nitride Microtube Array

PubMed Central

2015-01-01

In neural interface platforms, cultures are often carried out on a flat, open, rigid, and opaque substrate, posing challenges to reflecting the native microenvironment of the brain and precise engagement with neurons. Here we present a neuron cell culturing platform that consists of arrays of ordered microtubes (2.7–4.4 μm in diameter), formed by strain-induced self-rolled-up nanomembrane (s-RUM) technology using ultrathin (<40 nm) silicon nitride (SiNx) film on transparent substrates. These microtubes demonstrated robust physical confinement and unprecedented guidance effect toward outgrowth of primary cortical neurons, with a coaxially confined configuration resembling that of myelin sheaths. The dynamic neural growth inside the microtube, evaluated with continuous live-cell imaging, showed a marked increase (20×) of the growth rate inside the microtube compared to regions outside the microtubes. We attribute the dramatic accelerating effect and precise guiding of the microtube array to three-dimensional (3D) adhesion and electrostatic interaction with the SiNx microtubes, respectively. This work has clear implications toward building intelligent synthetic neural circuits by arranging the size, site, and patterns of the microtube array, for potential treatment of neurological disorders. PMID:25329686

Self-catalyzed GaAs nanowires on silicon by hydride vapor phase epitaxy.

PubMed

Dong, Zhenning; André, Yamina; Dubrovskii, Vladimir G; Bougerol, Catherine; Leroux, Christine; Ramdani, Mohammed R; Monier, Guillaume; Trassoudaine, Agnès; Castelluci, Dominique; Gil, Evelyne

2017-03-24

Gold-free GaAs nanowires on silicon substrates can pave the way for monolithic integration of photonic nanodevices with silicon electronic platforms. It is extensively documented that the self-catalyzed approach works well in molecular beam epitaxy but is much more difficult to implement in vapor phase epitaxies. Here, we report the first gallium-catalyzed hydride vapor phase epitaxy growth of long (more than 10 μm) GaAs nanowires on Si(111) substrates with a high integrated growth rate up to 60 μm h -1 and pure zincblende crystal structure. The growth is achieved by combining a low temperature of 600 °C with high gaseous GaCl/As flow ratios to enable dechlorination and formation of gallium droplets. GaAs nanowires exhibit an interesting bottle-like shape with strongly tapered bases, followed by straight tops with radii as small as 5 nm. We present a model that explains the peculiar growth mechanism in which the gallium droplets nucleate and rapidly swell on the silicon surface but then are gradually consumed to reach a stationary size. Our results unravel the necessary conditions for obtaining gallium-catalyzed GaAs nanowires by vapor phase epitaxy techniques.

Optical interconnection networks for high-performance computing systems

NASA Astrophysics Data System (ADS)

Biberman, Aleksandr; Bergman, Keren

2012-04-01

Enabled by silicon photonic technology, optical interconnection networks have the potential to be a key disruptive technology in computing and communication industries. The enduring pursuit of performance gains in computing, combined with stringent power constraints, has fostered the ever-growing computational parallelism associated with chip multiprocessors, memory systems, high-performance computing systems and data centers. Sustaining these parallelism growths introduces unique challenges for on- and off-chip communications, shifting the focus toward novel and fundamentally different communication approaches. Chip-scale photonic interconnection networks, enabled by high-performance silicon photonic devices, offer unprecedented bandwidth scalability with reduced power consumption. We demonstrate that the silicon photonic platforms have already produced all the high-performance photonic devices required to realize these types of networks. Through extensive empirical characterization in much of our work, we demonstrate such feasibility of waveguides, modulators, switches and photodetectors. We also demonstrate systems that simultaneously combine many functionalities to achieve more complex building blocks. We propose novel silicon photonic devices, subsystems, network topologies and architectures to enable unprecedented performance of these photonic interconnection networks. Furthermore, the advantages of photonic interconnection networks extend far beyond the chip, offering advanced communication environments for memory systems, high-performance computing systems, and data centers.

Interband π -like plasmon in silicene grown on silver

NASA Astrophysics Data System (ADS)

Sindona, A.; Cupolillo, A.; Alessandro, F.; Pisarra, M.; Coello Fiallos, D. C.; Osman, S. M.; Caputi, L. S.

2018-01-01

Silicene, the two-dimensional allotrope of silicon, is predicted to exist in a low-buckled honeycomb lattice, characterized by semimetallic electronic bands with graphenelike energy-momentum dispersions around the Fermi level (represented by touching Dirac cones). Single layers of silicene are mostly synthesized by depositing silicon on top of silver, where, however, the different phases observed to date are so strongly hybridized with the substrate that not only the Dirac cones, but also the whole valence and conduction states of ideal silicene appear to be lost. Here, we provide evidence that at least part of this semimetallic behavior is preserved by the coexistence of more silicene phases, epitaxially grown on Ag(111). In particular, we combine electron energy loss spectroscopy and time-dependent density functional theory to characterize the low-energy plasmon of a multiphase-silicene/Ag(111) sample, prepared at controlled silicon coverage and growth temperature. We find that this mode survives the interaction with the substrate, being perfectly matched with the π -like plasmon of ideal silicene. We therefore suggest that the weakened interaction of multiphase silicene with the substrate may provide a unique platform with the potential to develop different applications based on two-dimensional silicon systems.

Linear and passive silicon diodes, isolators, and logic gates

NASA Astrophysics Data System (ADS)

Li, Zhi-Yuan

2013-12-01

Silicon photonic integrated devices and circuits have offered a promising means to revolutionalize information processing and computing technologies. One important reason is that these devices are compatible with conventional complementary metal oxide semiconductor (CMOS) processing technology that overwhelms current microelectronics industry. Yet, the dream to build optical computers has yet to come without the breakthrough of several key elements including optical diodes, isolators, and logic gates with low power, high signal contrast, and large bandwidth. Photonic crystal has a great power to mold the flow of light in micrometer/nanometer scale and is a promising platform for optical integration. In this paper we present our recent efforts of design, fabrication, and characterization of ultracompact, linear, passive on-chip optical diodes, isolators and logic gates based on silicon two-dimensional photonic crystal slabs. Both simulation and experiment results show high performance of these novel designed devices. These linear and passive silicon devices have the unique properties of small fingerprint, low power request, large bandwidth, fast response speed, easy for fabrication, and being compatible with COMS technology. Further improving their performance would open up a road towards photonic logics and optical computing and help to construct nanophotonic on-chip processor architectures for future optical computers.

EDITORIAL: Special issue on silicon photonics

NASA Astrophysics Data System (ADS)

Reed, Graham; Paniccia, Mario; Wada, Kazumi; Mashanovich, Goran

2008-06-01

The technology now known as silicon photonics can be traced back to the pioneering work of Soref in the mid-1980s (see, for example, Soref R A and Lorenzo J P 1985 Electron. Lett. 21 953). However, the nature of the research conducted today, whilst it builds upon that early work, is unrecognizable in terms of technology metrics such as device efficiency, device data rate and device dimensions, and even in targeted applications areas. Today silicon photonics is still evolving, and is enjoying a period of unprecedented attention in terms of research focus. This has resulted in orders-of-magnitude improvement in device performance over the last few years to levels many thought were impossible. However, despite the existence of the research field for more than two decades, silicon is still regarded as a 'new' optical material, one that is being manipulated and modified to satisfy the requirements of a range of applications. This is somewhat ironic since silicon is one of the best known and most thoroughly studied materials, thanks to the electronics industry that has made silicon its material of choice. The principal reasons for the lack of study of this 'late developer' are that (i) silicon is an indirect bandgap material and (ii) it does not exhibit a linear electro-optic (Pockels) effect. The former condition means that it is difficult to make a laser in silicon based on the intrinsic performance of the material, and consequently, in recent years, researchers have attempted to modify the material to artificially engineer the conditions for lasing to be viable (see, for example, the review text, Jalali B et al 2008 Silicon Lasers in Silicon Photonics: The State of the Art ed G T Reed (New York: Wiley)). The latter condition means that optical modulators are intrinsically less efficient in silicon than in some other materials, particularly when targeting the popular telecommunications wavelengths around 1.55 μm. Therefore researchers have sought alternative mechanisms for modulation in silicon that have yielded increasingly impressive results (see, for example, Liao L et al 2007 Electron. Lett. 43 issue 22). The convergence of computing and communications and the resultant demand for increased bandwidth has been one of the factors influencing the upsurge of interest in silicon, together with the requirement for photonic and electronic integration, all to be realized at low cost. Thus emerging applications such as short-reach communications links for optical interconnect and fibre to the home (FTTH) (as well as a multitude of other applications) are frequently offered as examples of where silicon photonics will have a significant, perhaps a revolutionary, impact. One of the major conclusions of the joint MIT-industry Communication Technology Roadmap (http://mph-roadmap.mit.edu/index.php), was that 'Photonics technology will be driven by electronic-photonic synergy and short (<1 km) reach interconnection. This direction will ignite a major shift in leadership of the optical component industry from information transmission (telecom) to information processing (computing imaging).' Thus the case is made for low-cost implementation, making silicon a prime candidate, particularly if true electronic/photonic integration is to be realized. Despite the limitations of silicon as an optical material, the intrinsic advantages of the most popular silicon optical platform, silicon-on-insulator (SOI), should not be overlooked. The very high confinement nature of this technology platform brings a host of advantages, including the possibility to miniaturize devices and circuits, to reduce power consumption, optical loss and cost, to increase yield, and to be compatible with CMOS-based intelligence. Thus the limitations of silicon as an optical material can be offset against the very significant advantages, to both commercial as well as technological success. Of course, there is still much to do, hence the increasing global investment in silicon technology and the massive increase in research activity in silicon photonics since the early work in the 1980s. Only time will tell if silicon can realize its potential to satisfy the ever-increasing array of applications. However, the indications are positive, and the contributors to this cause employ increasingly impressive levels of intellectual and technological capability to realize the desired goals. It is an interesting time to be involved in slicon photonics, and it will be equally fascinating to watch the evolution of the technology in the future. Whatever happens, silicon will make the transition from being regarded as purely an electronic material to recognition as an optoelectronic material. The evidence for this is represented in the collection of papers that form this special issue of Semiconductor Science and Technology. This special issue is, in turn, representative of the rapidly increasing body of literature that represents the field of silicon photonics. In a field of such rapid transition as silicon photonics, the hope is that this special issue takes a snapshot of the technology at the time of publication, to document the progress of the field for future reference, and in turn to stimulate further work. The Guest Editors are grateful for the tireless support of Clare Bedrock at IOP Publishing.

Silicon Field Effect Transistors as Dual-Use Sensor-Heater Hybrids

PubMed Central

Reddy, Bobby; Elibol, Oguz H.; Nair, Pradeep R.; Dorvel, Brian R.; Butler, Felice; Ahsan, Zahab; Bergstrom, Donald E.; Alam, Muhammad A.; Bashir, Rashid

2011-01-01

We demonstrate the temperature mediated applications of a previously proposed novel localized dielectric heating method on the surface of dual purpose silicon field effect transistor (FET) sensor-heaters and perform modeling and characterization of the underlying mechanisms. The FETs are first shown to operate as electrical sensors via sensitivity to changes in pH in ionic fluids. The same devices are then demonstrated as highly localized heaters via investigation of experimental heating profiles and comparison to simulation results. These results offer further insight into the heating mechanism and help determine the spatial resolution of the technique. Two important biosensor platform applications spanning different temperature ranges are then demonstrated: a localized heat-mediated DNA exchange reaction and a method for dense selective functionalization of probe molecules via the heat catalyzed complete desorption and reattachment of chemical functionalization to the transistor surfaces. Our results show that the use of silicon transistors can be extended beyond electrical switching and field-effect sensing to performing localized temperature controlled chemical reactions on the transistor itself. PMID:21214189

High frequency acoustic on-chip integration for particle characterization and manipulation in microfluidics

NASA Astrophysics Data System (ADS)

Li, Sizhe; Carlier, Julien; Toubal, Malika; Liu, Huiqin; Campistron, Pierre; Callens, Dorothée; Nassar, Georges; Nongaillard, Bertrand; Guo, Shishang

2017-10-01

This letter presents a microfluidic device that integrates high frequency (650 MHz) bulk acoustic waves for the realization of particle handling on-chip. The core structure of the microfluidic chip is made up of a confocal lens, a vertical reflection wall, and a ZnO film transducer coupled with a silicon substrate for exciting acoustic beams. The excited acoustic waves propagate in bulk silicon and are then guided by a 45° silicon mirror into the suspensions in the microchannel; afterwards, the acoustic energy is focused on particles by the confocal lens and reflected by a reflection wall. Parts of the reflected acoustic energy backtrack into the transducer, and acoustic attenuation measurements are characterized for particle detection. Meanwhile, a strong acoustic streaming phenomenon can be seen around the reflection wall, which is used to implement particle manipulation. This platform opens a frontier for on-chip integration of high sensitivity acoustic characterization and localized acoustic manipulation in microfluidics.

High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate

PubMed Central

Witmer, Jeremy D.; Valery, Joseph A.; Arrangoiz-Arriola, Patricio; Sarabalis, Christopher J.; Hill, Jeff T.; Safavi-Naeini, Amir H.

2017-01-01

Future quantum networks, in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality (Q) factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical Q factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices. PMID:28406177

Organophosphonate-based PNA-functionalization of silicon nanowires for label-free DNA detection.

PubMed

Cattani-Scholz, Anna; Pedone, Daniel; Dubey, Manish; Neppl, Stefan; Nickel, Bert; Feulner, Peter; Schwartz, Jeffrey; Abstreiter, Gerhard; Tornow, Marc

2008-08-01

We investigated hydroxyalkylphosphonate monolayers as a novel platform for the biofunctionalization of silicon-based field effect sensor devices. This included a detailed study of the thin film properties of organophosphonate films on Si substrates using several surface analysis techniques, including AFM, ellipsometry, contact angle, X-ray photoelectron spectroscopy (XPS), X-ray reflectivity, and current-voltage characteristics in electrolyte solution. Our results indicate the formation of a dense monolayer on the native silicon oxide that has excellent passivation properties. The monolayer was biofunctionalized with 12 mer peptide nucleic acid (PNA) receptor molecules in a two-step procedure using the heterobifunctional linker, 3-maleimidopropionic-acid-N-hydroxysuccinimidester. Successful surface modification with the probe PNA was verified by XPS and contact angle measurements, and hybridization with DNA was determined by fluorescence measurements. Finally, the PNA functionalization protocol was translated to 2 microm long, 100 nm wide Si nanowire field effect devices, which were successfully used for label-free DNA/PNA hybridization detection.

Widely bandwidth-tunable silicon filter with an unlimited free-spectral range.

PubMed

St-Yves, Jonathan; Bahrami, Hadi; Jean, Philippe; LaRochelle, Sophie; Shi, Wei

2015-12-01

Next-generation high-capacity optical networks require flexible allocation of spectrum resources, for which low-cost optical filters with an ultra-wide bandwidth tunability beyond 100 GHz are desired. We demonstrate an integrated band-pass filter with the bandwidth continuously tuned across 670 GHz (117-788 GHz) which, to the best of our knowledge, is the widest tuning span ever demonstrated on a silicon chip. The filter also features simultaneous wavelength tuning and an unlimited free spectral range. We measured an out-of-band contrast of up to 55 dB, low in-band ripples of less than 0.3 dB, and in-band group delay variation of less than 8 ps. This result was achieved using cascaded Bragg-grating-assisted contra-directional couplers and micro-heaters on the 220 nm silicon-on-insulator platform with a very compact footprint of less than 7000  μm2. Another design with the bandwidth continuously tunable from 50 GHz to 1 THz is also presented.

Nanomechanical silicon resonators with intrinsic tunable gain and sub-nW power consumption.

PubMed

Bartsch, Sebastian T; Lovera, Andrea; Grogg, Daniel; Ionescu, Adrian M

2012-01-24

Nanoelectromechanical systems (NEMS) as integrated components for ultrasensitive sensing, time keeping, or radio frequency applications have driven the search for scalable nanomechanical transduction on-chip. Here, we present a hybrid silicon-on-insulator platform for building NEM oscillators in which fin field effect transistors (FinFETs) are integrated into nanomechanical silicon resonators. We demonstrate transistor amplification and signal mixing, coupled with mechanical motion at very high frequencies (25-80 MHz). By operating the transistor in the subthreshold region, the power consumption of resonators can be reduced to record-low nW levels, opening the way for the parallel operation of hundreds of thousands of NEM oscillators. The electromechanical charge modulation due to the field effect in a resonant transistor body constitutes a scalable nanomechanical motion detection all-on-chip and at room temperature. The new class of tunable NEMS represents a major step toward their integration in resonator arrays for applications in sensing and signal processing. © 2011 American Chemical Society

Hybrid Integrated Silicon Microfluidic Platform for Fluorescence Based Biodetection.

PubMed

Chandrasekaran, Arvind; Acharya, Ashwin; You, Jian Liang; Soo, Kim Young; Packirisamy, Muthukumaran; Stiharu, Ion; Darveau, André

2007-09-11

The desideratum to develop a fully integrated Lab-on-a-chip device capable ofrapid specimen detection for high throughput in-situ biomedical diagnoses and Point-of-Care testing applications has called for the integration of some of the novel technologiessuch as the microfluidics, microphotonics, immunoproteomics and Micro ElectroMechanical Systems (MEMS). In the present work, a silicon based microfluidic device hasbeen developed for carrying out fluorescence based immunoassay. By hybrid attachment ofthe microfluidic device with a Spectrometer-on-chip, the feasibility of synthesizing anintegrated Lab-on-a-chip type device for fluorescence based biosensing has beendemonstrated. Biodetection using the microfluidic device has been carried out usingantigen sheep IgG and Alexafluor-647 tagged antibody particles and the experimentalresults prove that silicon is a compatible material for the present application given thevarious advantages it offers such as cost-effectiveness, ease of bulk microfabrication,superior surface affinity to biomolecules, ease of disposability of the device etc., and is thussuitable for fabricating Lab-on-a-chip type devices.

Energy-Conversion Properties of Vapor-Liquid-Solid-Grown Silicon Wire-Array Photocathodes

NASA Astrophysics Data System (ADS)

Boettcher, Shannon W.; Spurgeon, Joshua M.; Putnam, Morgan C.; Warren, Emily L.; Turner-Evans, Daniel B.; Kelzenberg, Michael D.; Maiolo, James R.; Atwater, Harry A.; Lewis, Nathan S.

2010-01-01

Silicon wire arrays, though attractive materials for use in photovoltaics and as photocathodes for hydrogen generation, have to date exhibited poor performance. Using a copper-catalyzed, vapor-liquid-solid-growth process, SiCl4 and BCl3 were used to grow ordered arrays of crystalline p-type silicon (p-Si) microwires on p+-Si(111) substrates. When these wire arrays were used as photocathodes in contact with an aqueous methyl viologen2+/+ electrolyte, energy-conversion efficiencies of up to 3% were observed for monochromatic 808-nanometer light at fluxes comparable to solar illumination, despite an external quantum yield at short circuit of only 0.2. Internal quantum yields were at least 0.7, demonstrating that the measured photocurrents were limited by light absorption in the wire arrays, which filled only 4% of the incident optical plane in our test devices. The inherent performance of these wires thus conceptually allows the development of efficient photovoltaic and photoelectrochemical energy-conversion devices based on a radial junction platform.

Energy-conversion properties of vapor-liquid-solid-grown silicon wire-array photocathodes.

PubMed

Boettcher, Shannon W; Spurgeon, Joshua M; Putnam, Morgan C; Warren, Emily L; Turner-Evans, Daniel B; Kelzenberg, Michael D; Maiolo, James R; Atwater, Harry A; Lewis, Nathan S

2010-01-08

Silicon wire arrays, though attractive materials for use in photovoltaics and as photocathodes for hydrogen generation, have to date exhibited poor performance. Using a copper-catalyzed, vapor-liquid-solid-growth process, SiCl4 and BCl3 were used to grow ordered arrays of crystalline p-type silicon (p-Si) microwires on p+-Si(111) substrates. When these wire arrays were used as photocathodes in contact with an aqueous methyl viologen(2+/+) electrolyte, energy-conversion efficiencies of up to 3% were observed for monochromatic 808-nanometer light at fluxes comparable to solar illumination, despite an external quantum yield at short circuit of only 0.2. Internal quantum yields were at least 0.7, demonstrating that the measured photocurrents were limited by light absorption in the wire arrays, which filled only 4% of the incident optical plane in our test devices. The inherent performance of these wires thus conceptually allows the development of efficient photovoltaic and photoelectrochemical energy-conversion devices based on a radial junction platform.

60-nm-thick basic photonic components and Bragg gratings on the silicon-on-insulator platform.

PubMed

Zou, Zhi; Zhou, Linjie; Li, Xinwan; Chen, Jianping

2015-08-10

We demonstrate integrated basic photonic components and Bragg gratings using 60-nm-thick silicon-on-insulator strip waveguides. The ultra-thin waveguides exhibit a propagation loss of 0.61 dB/cm and a bending loss of approximately 0.015 dB/180° with a 30 μm bending radius (including two straight-bend waveguide junctions). Basic structures based on the ultra-thin waveguides, including micro-ring resonators, 1 × 2 MMI couplers, and Mach-Zehnder interferometers are realized. Upon thinning-down, the waveguide effective refractive index is reduced, making the fabrication of Bragg gratings possible using the standard 248-nm deep ultra-violet (DUV) photolithography process. The Bragg grating exhibits a stopband width of 1 nm and an extinction ratio of 35 dB, which is practically applicable as an optical filter or a delay line. The transmission spectrum can be thermally tuned via an integrated resistive micro-heater formed by a heavily doped silicon slab beside the waveguide.

Mechanism of erosion of nanostructured porous silicon drug carriers in neoplastic tissues

PubMed Central

Tzur-Balter, Adi; Shatsberg, Zohar; Beckerman, Margarita; Segal, Ester; Artzi, Natalie

2015-01-01

Nanostructured porous silicon (PSi) is emerging as a promising platform for drug delivery owing to its biocompatibility, degradability and high surface area available for drug loading. The ability to control PSi structure, size and porosity enables programming its in vivo retention, providing tight control over embedded drug release kinetics. In this work, the relationship between the in vitro and in vivo degradation of PSi under (pre)clinically relevant conditions, using breast cancer mouse model, is defined. We show that PSi undergoes enhanced degradation in diseased environment compared with healthy state, owing to the upregulation of reactive oxygen species (ROS) in the tumour vicinity that oxidize the silicon scaffold and catalyse its degradation. We further show that PSi degradation in vitro and in vivo correlates in healthy and diseased states when ROS-free or ROS-containing media are used, respectively. Our work demonstrates that understanding the governing mechanisms associated with specific tissue microenvironment permits predictive material performance. PMID:25670235

Nanostructured porous silicon-mediated drug delivery.

PubMed

Martín-Palma, Raúl J; Hernández-Montelongo, Jacobo; Torres-Costa, Vicente; Manso-Silván, Miguel; Muñoz-Noval, Álvaro

2014-08-01

The particular properties of nanostructured porous silicon (nanoPS) make it an attractive material for controlled and localized release of therapeutics within the body, aiming at increased efficacy and reduced risks of potential side effects. Since this is a rapidly evolving field as a consequence of the number of research groups involved, a critical review of the state of the art is necessary. In this work, the most promising and successful applications of nanoPS in the field of drug delivery are reviewed and discussed. Two key issues such as drug loading and release are also analyzed in detail. The development of multifunctional (hybrid) systems, aiming at imparting additional functionalities to the nanoPS particles such as luminescence, magnetic response and/or plasmonic effects (allowing simultaneous tracking and guiding), is also examined. Nanostructured materials based on silicon are promising platforms for pharmaceutical applications given their ability to degrade and low toxicity. However, a very limited number of clinical applications have been demonstrated so far.

Hydrogenated amorphous silicon nitride photonic crystals for improved-performance surface electromagnetic wave biosensors.

PubMed

Sinibaldi, Alberto; Descrovi, Emiliano; Giorgis, Fabrizio; Dominici, Lorenzo; Ballarini, Mirko; Mandracci, Pietro; Danz, Norbert; Michelotti, Francesco

2012-10-01

We exploit the properties of surface electromagnetic waves propagating at the surface of finite one dimensional photonic crystals to improve the performance of optical biosensors with respect to the standard surface plasmon resonance approach. We demonstrate that the hydrogenated amorphous silicon nitride technology is a versatile platform for fabricating one dimensional photonic crystals with any desirable design and operating in a wide wavelength range, from the visible to the near infrared. We prepared sensors based on photonic crystals sustaining either guided modes or surface electromagnetic waves, also known as Bloch surface waves. We carried out for the first time a direct experimental comparison of their sensitivity and figure of merit with surface plasmon polaritons on metal layers, by making use of a commercial surface plasmon resonance instrument that was slightly adapted for the experiments. Our measurements demonstrate that the Bloch surface waves on silicon nitride photonic crystals outperform surface plasmon polaritons by a factor 1.3 in terms of figure of merit.

High-directionality fiber-chip grating coupler with interleaved trenches and subwavelength index-matching structure.

PubMed

Benedikovic, Daniel; Alonso-Ramos, Carlos; Cheben, Pavel; Schmid, Jens H; Wang, Shurui; Xu, Dan-Xia; Lapointe, Jean; Janz, Siegfried; Halir, Robert; Ortega-Moñux, Alejandro; Wangüemert-Pérez, J Gonzalo; Molina-Fernández, Iñigo; Fédéli, Jean-Marc; Vivien, Laurent; Dado, Milan

2015-09-15

We present the first experimental demonstration of a new fiber-chip grating coupler concept that exploits the blazing effect by interleaving the standard full (220 nm) and shallow etch (70 nm) trenches in a 220 nm thick silicon layer. The high directionality is obtained by controlling the separation between the deep and shallow trenches to achieve constructive interference in the upward direction and destructive interference toward the silicon substrate. Utilizing this concept, the grating directionality can be maximized independent of the bottom oxide thickness. The coupler also includes a subwavelength-engineered index-matching region, designed to reduce the reflectivity at the interface between the injection waveguide and the grating. We report a measured fiber-chip coupling efficiency of -1.3  dB, the highest coupling efficiency achieved to date for a surface grating coupler in a 220 nm silicon-on-insulator platform fabricated in a conventional dual-etch process without high-index overlays or bottom mirrors.

Design and Implementation of an Interactive Website for Pediatric Voice Therapy-The Concept of In-Between Care: A Telehealth Model.

PubMed

Doarn, Charles R; Zacharias, Stephanie; Keck, Casey Stewart; Tabangin, Meredith; DeAlarcon, Alessandro; Kelchner, Lisa

2018-06-05

This article describes the design and implementation of a web-based portal developed to provide supported home practice between weekly voice therapy sessions delivered through telehealth to children with voice disorders. This in-between care consisted of supported home practice that was remotely monitored by speech-language pathologists (SLPs). A web-based voice therapy portal (VTP) was developed as a platform so participants could complete voice therapy home practice by an interdisciplinary team of SLPs (specialized in pediatric voice therapy), telehealth specialists, biomedical informaticians, and interface designers. The VTP was subsequently field tested in a group of children with voice disorders, participating in a larger telehealth study. Building the VTP for supported home practice for pediatric voice therapy was challenging, but successful. Key interactive features of the final site included 11 vocal hygiene questions, traditional voice therapy exercises grouped into levels, audio/visual voice therapy demonstrations, a store-and-retrieval system for voice samples, message/chat function, written guidelines for weekly therapy exercises, and questionnaires for parents to complete after each therapy session. Ten participants (9-14 years of age) diagnosed with a voice disorder were enrolled for eight weekly telehealth voice therapy sessions with follow-up in-between care provided using the VTP. The development and implementation of the VTP as a novel platform for the delivery of voice therapy home practice sessions were effective. We found that a versatile individual, who can work with all project staff (speak the language of both SLPs and information technologists), is essential to the development process. Once the website was established, participants and SLPs effectively utilized the web-based VTP. They found it feasible and useful for needed in-between care and reinforcement of therapeutic exercises.

From Apollo to Cognac

NASA Technical Reports Server (NTRS)

1980-01-01

Shell Oil Company started oil and gas production from a new offshore platform called Cognac located in the Gulf of Mexico. It is the world's tallest oil platform, slightly taller than the Empire State Building. The highly complex job of installing Cognac's support "jacket" under water more than a thousand feet deep was directed from a barge-based control center. To enable crews to practice in advance difficult tasks never before accomplished, Honeywell, adapting NASA's Apollo technology, developed a system for simulating the various underwater operations. In training sessions, displays and controls reacted exactly as they would in real operation.

Introduction to autonomous mobile robotics using Lego Mindstorms NXT

NASA Astrophysics Data System (ADS)

Akın, H. Levent; Meriçli, Çetin; Meriçli, Tekin

2013-12-01

Teaching the fundamentals of robotics to computer science undergraduates requires designing a well-balanced curriculum that is complemented with hands-on applications on a platform that allows rapid construction of complex robots, and implementation of sophisticated algorithms. This paper describes such an elective introductory course where the Lego Mindstorms NXT kits are used as the robot platform. The aims, scope and contents of the course are presented, and the design of the laboratory sessions as well as the term projects, which address several core problems of robotics and artificial intelligence simultaneously, are explained in detail.

Membrane on a Chip: A Functional Tethered Lipid Bilayer Membrane on Silicon Oxide Surfaces

PubMed Central

Atanasov, Vladimir; Knorr, Nikolaus; Duran, Randolph S.; Ingebrandt, Sven; Offenhäusser, Andreas; Knoll, Wolfgang; Köper, Ingo

2005-01-01

Tethered membranes have been proven during recent years to be a powerful and flexible biomimetic platform. We reported in a previous article on the design of a new architecture based on the self-assembly of a thiolipid on ultrasmooth gold substrates, which shows extremely good electrical sealing properties as well as functionality of a bilayer membrane. Here, we describe the synthesis of lipids for a more modular design and the adaptation of the linker part to silane chemistry. We were able to form a functional tethered bilayer lipid membrane with good electrical sealing properties covering a silicon oxide surface. We demonstrate the functional incorporation of the ion carrier valinomycin and of the ion channel gramicidin. PMID:16127170

Metropolitan Quantum Key Distribution with Silicon Photonics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bunandar, Darius; Lentine, Anthony; Lee, Catherine

Photonic integrated circuits provide a compact and stable platform for quantum photonics. Here we demonstrate a silicon photonics quantum key distribution (QKD) encoder in the first high-speed polarization-based QKD field tests. The systems reach composable secret key rates of 1.039 Mbps in a local test (on a 103.6-m fiber with a total emulated loss of 9.2 dB) and 157 kbps in an intercity metropolitan test (on a 43-km fiber with 16.4 dB loss). Our results represent the highest secret key generation rate for polarization-based QKD experiments at a standard telecom wavelength and demonstrate photonic integrated circuits as a promising, scalablemore » resource for future formation of metropolitan quantum-secure communications networks.« less

Metropolitan Quantum Key Distribution with Silicon Photonics

DOE PAGES

Bunandar, Darius; Lentine, Anthony; Lee, Catherine; ...

2018-04-06

Photonic integrated circuits provide a compact and stable platform for quantum photonics. Here we demonstrate a silicon photonics quantum key distribution (QKD) encoder in the first high-speed polarization-based QKD field tests. The systems reach composable secret key rates of 1.039 Mbps in a local test (on a 103.6-m fiber with a total emulated loss of 9.2 dB) and 157 kbps in an intercity metropolitan test (on a 43-km fiber with 16.4 dB loss). Our results represent the highest secret key generation rate for polarization-based QKD experiments at a standard telecom wavelength and demonstrate photonic integrated circuits as a promising, scalablemore » resource for future formation of metropolitan quantum-secure communications networks.« less

Integration of hybrid silicon lasers and electroabsorption modulators.

PubMed

Sysak, Matthew N; Anthes, Joel O; Bowers, John E; Raday, Omri; Jones, Richard

2008-08-18

We present an integration platform based on quantum well intermixing for multi-section hybrid silicon lasers and electroabsorption modulators. As a demonstration of the technology, we have fabricated discrete sampled grating DBR lasers and sampled grating DBR lasers integrated with InGaAsP/InP electroabsorption modulators. The integrated sampled grating DBR laser-modulators use the as-grown III-V bandgap for optical gain, a 50 nm blue shifted bandgap for the electrabosprtion modulators, and an 80 nm blue shifted bandgap for low loss mirrors. Laser continuous wave operation up to 45 ?C is achieved with output power >1.0 mW and threshold current of <50 mA. The modulator bandwidth is >2GHz with 5 dB DC extinction.

Performance tradeoff between lateral and interdigitated doping patterns for high speed carrier-depletion based silicon modulators.

PubMed

Yu, Hui; Pantouvaki, Marianna; Van Campenhout, Joris; Korn, Dietmar; Komorowska, Katarzyna; Dumon, Pieter; Li, Yanlu; Verheyen, Peter; Absil, Philippe; Alloatti, Luca; Hillerkuss, David; Leuthold, Juerg; Baets, Roel; Bogaerts, Wim

2012-06-04

Carrier-depletion based silicon modulators with lateral and interdigitated PN junctions are compared systematically on the same fabrication platform. The interdigitated diode is shown to outperform the lateral diode in achieving a low VπLπ of 0.62 V∙cm with comparable propagation loss at the expense of a higher depletion capacitance. The low VπLπ of the interdigitated PN junction is employed to demonstrate 10 Gbit/s modulation with 7.5 dB extinction ration from a 500 µm long device whose static insertion loss is 2.8 dB. In addition, up to 40 Gbit/s modulation is demonstrated for a 3 mm long device comprising a lateral diode and a co-designed traveling wave electrode.

Resonant second harmonic generation in a gallium nitride two-dimensional photonic crystal on silicon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zeng, Y.; Roland, I.; Checoury, X.

We demonstrate second harmonic generation in a gallium nitride photonic crystal cavity embedded in a two-dimensional free-standing photonic crystal platform on silicon. The photonic crystal nanocavity is optically pumped with a continuous-wave laser at telecom wavelengths in the transparency window of the nitride material. The harmonic generation is evidenced by the spectral range of the emitted signal, the quadratic power dependence vs. input power, and the spectral dependence of second harmonic signal. The harmonic emission pattern is correlated to the harmonic polarization generated by the second-order nonlinear susceptibilities χ{sub zxx}{sup (2)}, χ{sub zyy}{sup (2)} and the electric fields of the fundamentalmore » cavity mode.« less

Influence of porosity on thermophysical properties of a composite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grishaeva, N. Yu., E-mail: anohina@mail2000.ru; Ljukshin, B. A., E-mail: lba2008@yandex.ru; Bochkareva, S. A., E-mail: svetlanab7@yandex.ru

2015-10-27

In many modern information systems, the heat generated during the operation of electronic devices is usually dissipated by heat-conductive pads between the casing of the respective equipment and a massive base (platform). For newly developed pads, the promising materials are composites on the basis of various types of silicone rubber. At the same time, during the production of the pads without a vacuum setup, the material can contain air bubbles, which causes the porosity potentially negative for the thermal properties of the material. This work studies the thermal conductivity depending on the degree of silicone matrix filling by copper particles,more » introduced to improve thermal conductivity, and by air bubbles that are considered as reinforcing inclusions.« less

A fluid collection system for dermal wounds in clinical investigations

PubMed Central

Klopfer, Michael; Li, G.-P.; Widgerow, Alan; Bachman, Mark

2016-01-01

In this work, we demonstrate the use of a thin, self adherent, and clinically durable patch device that can collect fluid from a wound site for analysis. This device is manufactured from laminated silicone layers using a novel all-silicone double-molding process. In vitro studies for flow and delivery were followed by a clinical demonstration for exudate collection efficiency from a clinically presented partial thickness burn. The demonstrated utility of this device lends itself for use as a research implement used to clinically sample wound exudate for analysis. This device can serve as a platform for future integration of wearable technology into wound monitoring and care. The demonstrated fabrication method can be used for devices requiring thin membrane construction. PMID:27051470

Metropolitan Quantum Key Distribution with Silicon Photonics

NASA Astrophysics Data System (ADS)

Bunandar, Darius; Lentine, Anthony; Lee, Catherine; Cai, Hong; Long, Christopher M.; Boynton, Nicholas; Martinez, Nicholas; DeRose, Christopher; Chen, Changchen; Grein, Matthew; Trotter, Douglas; Starbuck, Andrew; Pomerene, Andrew; Hamilton, Scott; Wong, Franco N. C.; Camacho, Ryan; Davids, Paul; Urayama, Junji; Englund, Dirk

2018-04-01

Photonic integrated circuits provide a compact and stable platform for quantum photonics. Here we demonstrate a silicon photonics quantum key distribution (QKD) encoder in the first high-speed polarization-based QKD field tests. The systems reach composable secret key rates of 1.039 Mbps in a local test (on a 103.6-m fiber with a total emulated loss of 9.2 dB) and 157 kbps in an intercity metropolitan test (on a 43-km fiber with 16.4 dB loss). Our results represent the highest secret key generation rate for polarization-based QKD experiments at a standard telecom wavelength and demonstrate photonic integrated circuits as a promising, scalable resource for future formation of metropolitan quantum-secure communications networks.

Enhanced photoluminescence of Si nanocrystals-doped cellulose nanofibers by plasmonic light scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugimoto, Hiroshi; Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501; Zhang, Ran

2015-07-27

We report the development of bio-compatible cellulose nanofibers doped with light emitting silicon nanocrystals and Au nanoparticles via facile electrospinning. By performing photoluminescence (PL) spectroscopy as a function of excitation wavelength, we demonstrate plasmon-enhanced PL by a factor of 2.2 with negligible non-radiative quenching due to plasmon-enhanced scattering of excitation light from Au nanoparticles to silicon nanocrystals inside the nanofibers. These findings provide an alternative approach for the development of plasmon-enhanced active systems integrated within the compact nanofiber geometry. Furthermore, bio-compatible light-emitting nanofibers prepared by a cost-effective solution-based processing are very promising platforms for biophotonic applications such as fluorescence sensingmore » and imaging.« less

On-chip optical transduction scheme for graphene nano-electro-mechanical systems in silicon-photonic platform.

PubMed

Dash, Aneesh; Selvaraja, S K; Naik, A K

2018-02-15

We present a scheme for on-chip optical transduction of strain and displacement of graphene-based nano-electro-mechanical systems (NEMS). A detailed numerical study on the feasibility of three silicon-photonic integrated circuit configurations is presented: the Mach-Zehnder interferometer (MZI), the micro-ring resonator, and the ring-loaded MZI. An index sensing based technique using an MZI loaded with a ring resonator with a moderate Q-factor of 2400 can yield a sensitivity of 28  fm/Hz and 6.5×10 -6 %/Hz for displacement and strain, respectively. Though any phase-sensitive integrated-photonic device could be used for optical transduction, here we show that optimal sensitivity is achievable by combining resonance with phase sensitivity.

On-chip optical transduction scheme for graphene nano-electro-mechanical systems in silicon-photonic platform

NASA Astrophysics Data System (ADS)

Dash, Aneesh; Selvaraja, S. K.; Naik, A. K.

2018-02-01

We present a scheme for on-chip optical transduction of strain and displacement of Graphene-based Nano-Electro-Mechanical Systems (NEMS). A detailed numerical study on the feasibility of three silicon-photonic integrated circuit configurations is presented: Mach-Zehnder Interferometer(MZI), micro-ring resonator and ring-loaded MZI. An index-sensing based technique using a Mach-Zehnder Interferometer loaded with a ring resonator with a moderate Q-factor of 2400 can yield a sensitivity of 28 fm/sqrt(Hz), and 6.5E-6 %/sqrt(Hz) for displacement and strain respectively. Though any phase sensitive integrated photonic device could be used for optical transduction, here we show that optimal sensitivity is achievable by combining resonance with phase sensitivity.

High-speed polarization-encoded quantum key distribution based on silicon photonic integrated devices

NASA Astrophysics Data System (ADS)

Bunandar, Darius; Urayama, Junji; Boynton, Nicholas; Martinez, Nicholas; Derose, Christopher; Lentine, Anthony; Davids, Paul; Camacho, Ryan; Wong, Franco; Englund, Dirk

We present a compact polarization-encoded quantum key distribution (QKD) transmitter near a 1550-nm wavelength implemented on a CMOS-compatible silicon-on-insulator photonics platform. The transmitter generates arbitrary polarization qubits at gigahertz bandwidth with an extinction ratio better than 30 dB using high-speed carrier-depletion phase modulators. We demonstrate the performance of this device by generating secret keys at a rate of 1 Mbps in a complete QKD field test. Our work shows the potential of using advanced photonic integrated circuits to enable high-speed quantum-secure communications. This work was supported by the SECANT QKD Grand Challenge, the Samsung Global Research Outreach Program, and the Air Force Office of Scientific Research.

Advances in microfluidic devices made from thermoplastics used in cell biology and analyses.

PubMed

Gencturk, Elif; Mutlu, Senol; Ulgen, Kutlu O

2017-09-01

Silicon and glass were the main fabrication materials of microfluidic devices, however, plastics are on the rise in the past few years. Thermoplastic materials have recently been used to fabricate microfluidic platforms to perform experiments on cellular studies or environmental monitoring, with low cost disposable devices. This review describes the present state of the development and applications of microfluidic systems used in cell biology and analyses since the year 2000. Cultivation, separation/isolation, detection and analysis, and reaction studies are extensively discussed, considering only microorganisms (bacteria, yeast, fungi, zebra fish, etc.) and mammalian cell related studies in the microfluidic platforms. The advantages/disadvantages, fabrication methods, dimensions, and the purpose of creating the desired system are explained in detail. An important conclusion of this review is that these microfluidic platforms are still open for research and development, and solutions need to be found for each case separately.

Retention in porous layer pillar array planar separation platforms

DOE PAGES

Lincoln, Danielle R.; Lavrik, Nickolay V.; Kravchenko, Ivan I.; ...

2016-08-11

Here, this work presents the retention capabilities and surface area enhancement of highly ordered, high-aspect-ratio, open-platform, two-dimensional (2D) pillar arrays when coated with a thin layer of porous silicon oxide (PSO). Photolithographically prepared pillar arrays were coated with 50–250 nm of PSO via plasma-enhanced chemical vapor deposition and then functionalized with either octadecyltrichlorosilane or n-butyldimethylchlorosilane. Theoretical calculations indicate that a 50 nm layer of PSO increases the surface area of a pillar nearly 120-fold. Retention capabilities were tested by observing capillary-action-driven development under various conditions, as well as by running one-dimensional separations on varying thicknesses of PSO. Increasing the thicknessmore » of PSO on an array clearly resulted in greater retention of the analyte(s) in question in both experiments. In culmination, a two-dimensional separation of fluorescently derivatized amines was performed to further demonstrate the capabilities of these fabricated platforms.« less

Retention in porous layer pillar array planar separation platforms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lincoln, Danielle R.; Lavrik, Nickolay V.; Kravchenko, Ivan I.

Here, this work presents the retention capabilities and surface area enhancement of highly ordered, high-aspect-ratio, open-platform, two-dimensional (2D) pillar arrays when coated with a thin layer of porous silicon oxide (PSO). Photolithographically prepared pillar arrays were coated with 50–250 nm of PSO via plasma-enhanced chemical vapor deposition and then functionalized with either octadecyltrichlorosilane or n-butyldimethylchlorosilane. Theoretical calculations indicate that a 50 nm layer of PSO increases the surface area of a pillar nearly 120-fold. Retention capabilities were tested by observing capillary-action-driven development under various conditions, as well as by running one-dimensional separations on varying thicknesses of PSO. Increasing the thicknessmore » of PSO on an array clearly resulted in greater retention of the analyte(s) in question in both experiments. In culmination, a two-dimensional separation of fluorescently derivatized amines was performed to further demonstrate the capabilities of these fabricated platforms.« less

Direct current microhollow cathode discharges on silicon devices operating in argon and helium

NASA Astrophysics Data System (ADS)

Michaud, R.; Felix, V.; Stolz, A.; Aubry, O.; Lefaucheux, P.; Dzikowski, S.; Schulz-von der Gathen, V.; Overzet, L. J.; Dussart, R.

2018-02-01

Microhollow cathode discharges have been produced on silicon platforms using processes usually used for MEMS fabrication. Microreactors consist of 100 or 150 μm-diameter cavities made from Ni and SiO2 film layers deposited on a silicon substrate. They were studied in the direct current operating mode in two different geometries: planar and cavity configuration. Currents in the order of 1 mA could be injected in microdischarges operating in different gases such as argon and helium at a working pressure between 130 and 1000 mbar. When silicon was used as a cathode, the microdischarge operation was very unstable in both geometry configurations. Strong current spikes were produced and the microreactor lifetime was quite short. We evidenced the fast formation of blisters at the silicon surface which are responsible for the production of these high current pulses. EDX analysis showed that these blisters are filled with argon and indicate that an implantation mechanism is at the origin of this surface modification. Reversing the polarity of the microdischarge makes the discharge operate stably without current spikes, but the discharge appearance is quite different from the one obtained in direct polarity with the silicon cathode. By coating the silicon cathode with a 500 nm-thick nickel layer, the microdischarge becomes very stable with a much longer lifetime. No current spikes are observed and the cathode surface remains quite smooth compared to the one obtained without coating. Finally, arrays of 76 and 576 microdischarges were successfully ignited and studied in argon. At a working pressure of 130 mbar, all microdischarges are simultaneously ignited whereas they ignite one by one at higher pressure.

Status of development of LCOS projection displays for F-22A, F/A-18E/F, and JSF cockpits

NASA Astrophysics Data System (ADS)

Kalmanash, Michael H.

2001-09-01

Projection display technology has been found to be an attractive alternative to direct view flat panel displays in many avionics applications. The projection approach permits compact high performance systems to be tailored to specific platform needs while using a complement of commercial off the shelf (COTS) components, including liquid crystal on silicon (LCOS) microdisplay imagers. A common projection engine used on multiple platforms enables improved performance, lower cost and shorter development cycles. This paper provides a status update for projection displays under development for the F-22A, the F/A-18E/F and the Lockheed Joint Strike Fighter (JSF) aircraft.

Micron-Scale Differential Scanning Calorimeter on a Chip

DOEpatents

Cavicchi, Richard E; Poirier, Gregory Ernest; Suehle, John S; Gaitan, Michael; Tea, Nim H

1998-06-30

A differential scanning microcalorimeter produced on a silicon chip enables microscopic scanning calorimetry measurements of small samples and thin films. The chip may be fabricated using standard CMOS processes. The microcalorimeter includes a reference zone and a sample zone. The reference and sample zones may be at opposite ends of a suspended platform or may reside on separate platforms. An integrated polysilicon heater provides heat to each zone. A thermopile consisting of a succession of thermocouple junctions generates a voltage representing the temperature difference between the reference and sample zones. Temperature differences between the zones provide information about the chemical reactions and phase transitions that occur in a sample placed in the sample zone.

Photonic Hilbert transformers based on laterally apodized integrated waveguide Bragg gratings on a SOI wafer.

PubMed

Bazargani, Hamed Pishvai; Burla, Maurizio; Chrostowski, Lukas; Azaña, José

2016-11-01

We experimentally demonstrate high-performance integer and fractional-order photonic Hilbert transformers based on laterally apodized Bragg gratings in a silicon-on-insulator technology platform. The sub-millimeter-long gratings have been fabricated using single-etch electron beam lithography, and the resulting HT devices offer operation bandwidths approaching the THz range, with time-bandwidth products between 10 and 20.

Ion Channel Conductance Measurements on a Silicon-Based Platform

DTIC Science & Technology

2006-01-01

calculated using the molecular dynamics code, GROMACS . Reasonable agreement is obtained in the simulated versus measured conductance over the range of...measurements of the lipid giga-seal characteristics have been performed, including AC conductance measurements and statistical analysis in order to...Dynamics kernel self-consistently coupled to Poisson equations using a P3M force field scheme and the GROMACS description of protein structure and

Dissecting the role of sessional anatomy teachers: A systematic literature review.

PubMed

Rhodes, Danielle; Fogg, Quentin A; Lazarus, Michelle D

2017-12-04

Worldwide there is a growing reliance on sessional teachers in universities. This has impacted all disciplines in higher education including medical anatomy programs. The objective of this review was to define the role and support needs of sessional anatomy teachers by reporting on the (1) qualifications, (2) teaching role, (3) training, and (4) performance management of this group of educators. A systematic literature search was conducted on the 27 July 2017 in Scopus, Web of Science, and several databases on the Ovid, ProQuest and EBSCOhost platforms. The search retrieved 5,658 articles, with 39 deemed eligible for inclusion. The qualifications and educational distance between sessional anatomy teachers and their students varied widely. Reports of cross-level, near-peer and reciprocal-peer teaching were identified, with most institutes utilizing recent medical graduates or medical students as sessional teachers. Sessional anatomy teachers were engaged in the full spectrum of teaching-related duties from assisting students with cadaveric dissection, to marking student assessments and developing course materials. Fourteen institutes reported that training was provided to sessional anatomy teachers, but the specific content, objectives, methods and effectiveness of the training programs were rarely defined. Evaluations of sessional anatomy teacher performance primarily relied on subjective feedback measures such as student surveys (n = 18) or teacher self-assessment (n = 3). The results of this systematic review highlight the need for rigorous explorations of the use of sessional anatomy teachers in medical education, and the development of evidence-based policies and training programs that regulate and support the use of sessional teachers in higher education. Anat Sci Educ. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

Hippotherapy on postural balance in the sitting position of children with cerebral palsy - Longitudinal study.

PubMed

Moraes, Andréa Gomes; Copetti, Fernando; Ângelo, Vera Regina; Chiavoloni, Luana; de David, Ana Cristina

2018-06-11

To verify the effects of 12, 24, 36 hippotherapy sessions over time on postural balance while sitting in children with cerebral palsy as well the effects of treatment after one interruption period of 45 days. Hippotherapy program with a twice-weekly treatment with a total of 13 children aged 5-10 years old. Measurements of postural balance during sitting were performed using the AMTI AccuSway Plus platform. There was a statistically significant reduction in mediolateral and anteroposterior sway after the first 12 hippotherapy sessions, and further significant sway reduction occurred as the treatment progressed. Changes in the center of pressure displacement velocity variable began to occur after 24 sessions. Seated postural balance improved in children with cerebral palsy, as evidenced by lower COP displacement, particularly after a greater number of sessions. After the last evaluations, when completing 36 sessions of hippotherapy, it was verified that the improvements to the postural balance continued to occur. Therefore, further studies with a longer treatment period may help to clarify if, at some point, there is stabilization in the improvement of postural balance. Furthermore, it is important to analyze the impact of hippotherapy on functional activities over time.

Meeting report for mobile DNA 2010.

PubMed

Chaconas, George; Craig, Nancy; Curcio, M Joan; Deininger, Prescott; Feschotte, Cedric; Levin, Henry; Rice, Phoebe A; Voytas, Daniel F

2010-08-24

An international conference on mobile DNA was held 24-28 April 2010 in Montreal, Canada. Sponsored by the American Society for Microbiology, the conference's goal was to bring together researchers from around the world who study transposition in diverse organisms using multiple experimental approaches. The meeting drew over 190 attendees and most contributed through poster presentations, invited talks and short talks selected from poster abstracts. The talks were organized into eight scientific sessions, which ranged in topic from the evolutionary dynamics of mobile genetic elements to transposition reaction mechanisms. Here we present highlights from the platform sessions with a focus on talks presented by the invited speakers.

The silicon chip: A versatile micro-scale platform for micro- and nano-scale systems

NASA Astrophysics Data System (ADS)

Choi, Edward

Cutting-edge advances in micro- and nano-scale technology require instrumentation to interface with the external world. While technology feature sizes are continually being reduced, the size of experimentalists and their instrumentation do not mirror this trend. Hence there is a need for effective application-specific instrumentation to bridge the gap from the micro and nano-scale phenomena being studied to the comparative macro-scale of the human interfaces. This dissertation puts forward the idea that the silicon CMOS integrated circuit, or microchip in short, serves as an excellent platform to perform this functionality. The electronic interfaces designed for the semiconductor industry are particularly attractive as development platforms, and the reduction in feature sizes that has been a hallmark of the industry suggests that chip-scale instrumentation may be more closely coupled to the phenomena of interest, allowing finer control or improved measurement capabilities. Compatibility with commercial processes will further enable economies of scale through mass production, another welcome feature of this approach. Thus chip-scale instrumentation may replace the bulky, expensive, cumbersome-to-operate macro-scale prototypes currently in use for many of these applications. The dissertation examines four specific applications in which the chip may serve as the ideal instrumentation platform. These are nanorod manipulation, polypyrrole bilayer hinge microactuator control, organic transistor hybrid circuits, and contact fluorescence imaging. The thesis is structured around chapters devoted to each of these projects, in addition to a chapter on preliminary work on an RFID system that serves as a wireless interface model. Each of these chapters contains tools and techniques developed for chip-scale instrumentation, from custom scripts for automated layout and data collection to microfabrication processes. Implementation of these tools to develop systems for the applications above is evaluated. The viability of this approach is not limited to the examples listed in this work, and innovative new methodologies beyond those included here may be developed in the future for other systems which would benefit from the versatility of chip-scale platforms.

Using virtual reality to rehabilitate neglect.

PubMed

Sedda, A; Borghese, N A; Ronchetti, M; Mainetti, R; Pasotti, F; Beretta, G; Bottini, G

2013-01-01

Virtual Reality (VR) platforms gained a lot of attention in the rehabilitation field due to their ability to engage patients and the opportunity they offer to use real world scenarios. As neglect is characterized by an impairment in exploring space that greatly affects daily living, VR could be a powerful tool compared to classical paper and pencil tasks and computer training. Nevertheless, available platforms are costly and obstructive. Here we describe a low cost platform for neglect rehabilitation, that using consumer equipments allows the patient to train at home in an intensive fashion. We tested the platform on IB, a chronic neglect patient, who did not benefit from classical rehabilitation. Our results show that IB improved both in terms of neglect and attention. Importantly, these ameliorations lasted at a follow up evaluation 5 months after the last treatment session and generalized to everyday life activities. VR platforms built using equipment technology and following theoretical principles on brain functioning may induce greater ameliorations in visuo-spatial deficits than classical paradigms possibly thanks to the real world scenarios in association with the "visual feedback" of the patient's own body operating in the virtual environment.

DoctorEye: A clinically driven multifunctional platform, for accurate processing of tumors in medical images.

PubMed

Skounakis, Emmanouil; Farmaki, Christina; Sakkalis, Vangelis; Roniotis, Alexandros; Banitsas, Konstantinos; Graf, Norbert; Marias, Konstantinos

2010-01-01

This paper presents a novel, open access interactive platform for 3D medical image analysis, simulation and visualization, focusing in oncology images. The platform was developed through constant interaction and feedback from expert clinicians integrating a thorough analysis of their requirements while having an ultimate goal of assisting in accurately delineating tumors. It allows clinicians not only to work with a large number of 3D tomographic datasets but also to efficiently annotate multiple regions of interest in the same session. Manual and semi-automatic segmentation techniques combined with integrated correction tools assist in the quick and refined delineation of tumors while different users can add different components related to oncology such as tumor growth and simulation algorithms for improving therapy planning. The platform has been tested by different users and over large number of heterogeneous tomographic datasets to ensure stability, usability, extensibility and robustness with promising results. the platform, a manual and tutorial videos are available at: http://biomodeling.ics.forth.gr. it is free to use under the GNU General Public License.

Laser desorption/ionization from nanostructured surfaces: nanowires, nanoparticle films and silicon microcolumn arrays

NASA Astrophysics Data System (ADS)

Chen, Yong; Luo, Guanghong; Diao, Jiajie; Chornoguz, Olesya; Reeves, Mark; Vertes, Akos

2007-04-01

Due to their optical properties and morphology, thin films formed of nanoparticles are potentially new platforms for soft laser desorption/ionization (SLDI) mass spectrometry. Thin films of gold nanoparticles (with 12±1 nm particle size) were prepared by evaporation-driven vertical colloidal deposition and used to analyze a series of directly deposited polypeptide samples. In this new SLDI method, the required laser fluence for ion detection was equal or less than what was needed for matrix-assisted laser desorption/ionization (MALDI) but the resulting spectra were free of matrix interferences. A silicon microcolumn array-based substrate (a.k.a. black silicon) was developed as a new matrix-free laser desorption ionization surface. When low-resistivity silicon wafers were processed with a 22 ps pulse length 3×ω Nd:YAG laser in air, SF6 or water environment, regularly arranged conical spikes emerged. The radii of the spike tips varied with the processing environment, ranging from approximately 500 nm in water, to ~2 µm in SF6 gas and to ~5 µm in air. Peptide mass spectra directly induced by a nitrogen laser showed the formation of protonated ions of angiotensin I and II, substance P, bradykinin fragment 1-7, synthetic peptide, pro14-arg, and insulin from the processed silicon surfaces but not from the unprocessed areas. Threshold fluences for desorption/ionization were similar to those used in MALDI. Although compared to silicon nanowires the threshold laser pulse energy for ionization is significantly (~10×) higher, the ease of production and robustness of microcolumn arrays offer complementary benefits.

Changes in Jump-Down Performance After Space Flight: Short- and Long-Term Adaptation

NASA Technical Reports Server (NTRS)

Kofman, I. S.; Reschke, M. F.; Cerisano, J. M.; Fisher, E. A.; Lawrence, E. L.; Peters, B. T.; Bloomberg, J. J.

2010-01-01

INTRODUCTION Successful jump performance requires functional coordination of visual, vestibular, and somatosensory systems, which are affected by prolonged exposure to microgravity. Astronauts returning from space flight exhibit impaired ability to coordinate effective landing strategies when jumping from a platform to the ground. This study compares the jump strategies used by astronauts before and after flight, the changes to those strategies within a test session, and the recoveries in jump-down performance parameters across several postflight test sessions. These data were obtained as part of an ongoing interdisciplinary study (Functional Task Test, FTT) designed to evaluate both astronaut postflight functional performance and related physiological changes. METHODS Six astronauts from short-duration (Shuttle) and three from long-duration (International Space Station) flights performed 3 two-footed jumps from a platform 30 cm high. A force plate measured the ground reaction forces and center-of-pressure displacement from the landings. Muscle activation data were collected from the medial gastrocnemius and anterior tibialis of both legs using surface electromyography electrodes. Two load cells in the platform measured the load exerted by each foot during the takeoff phase of the jump. Data were collected in 2 preflight sessions, on landing day (Shuttle only), and 1, 6, and 30 days after flight. RESULTS AND CONCLUSION Many of the astronauts tested were unable to maintain balance on their first postflight jump landing but recovered by the third jump, showing a learning progression in which the performance improvement could be attributed to adjustments of strategy on takeoff, landing, or both. Takeoff strategy changes were evident in air time (time between takeoff and landing), which was significantly reduced after flight, and also in increased asymmetry in foot latencies on takeoff. Landing modifications were seen in changes in ground reaction force curves. The results demonstrate astronauts adaptive capabilities and full performance recovery within days after flight.

The effects of low-frequency vibrations on hepatic profile of blood

NASA Astrophysics Data System (ADS)

Damijan, Z.

2008-02-01

Body vibrations training has become popular in sports training, fitness activity, it is still a rare form of physical rehabilitation.. Vibrations are transmitted onto the whole body or some body parts of an exercising person via a vibration platform subjected to mechanical vertical vibrations. During the training session a participant has to maintain his body position or do exercises that engage specific muscles whilst vibrations of the platform are transmitted onto the person's body. This paper is the continuation of the earlier study covering the effects of low-frequency vibrations on selected physiological parameters of the human body. The experiments were conducted to find the answer to the question if vibration exposure (total duration of training sessions 6 hours 20 min) should produce any changes in hepatic profile of blood. Therefore a research program was undertaken at the University of Science and Technology AGH UST to investigate the effects of low-frequency vibration on selected parameters of hepatic profile of human blood. Cyclic fluctuations of bone loading were induced by the applied harmonic vibration 3.5 Hz and amplitude 0.004 m. The experiments utilizing two vibrating platforms were performed in the Laboratory of Structural Acoustics and Biomedical Engineering AGH-UST. The applied vibrations were harmless and not annoying, in accordance with the standard PN-EN ISO 130901-1, 1998. 23 women volunteers had 19 sessions on subsequent working days, at the same time of day. during the tests the participants remained in the standing position, passive. The main hypothesis has it that short-term low-frequency vibration exposure might bring about the changes of the hepatic profile of blood, including: bilirubin (BILIRUBIN), alkaline phosphatase (Alp), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and albumin (ALBUMIN) levels. Research data indicate the low-frequency vibrations exposure produces statistically significant decrease of bilirubin level [umol/l] in blood serum from 14.05 to 9.70 for 82% of participants, the probability level being p = 0.000041.

High Level of Integration in Integrated Disease Management Leads to Higher Usage in the e-Vita Study: Self-Management of Chronic Obstructive Pulmonary Disease With Web-Based Platforms in a Parallel Cohort Design

PubMed Central

Verdijk, Noortje A; Kasteleyn, Marise J; Harmans, Lara M; Talboom, Irvin JSH; Numans, Mattijs E; Chavannes, Niels H

2017-01-01

Background Worldwide, nearly 3 million people die of chronic obstructive pulmonary disease (COPD) every year. Integrated disease management (IDM) improves disease-specific quality of life and exercise capacity for people with COPD, but can also reduce hospital admissions and hospital days. Self-management of COPD through eHealth interventions has shown to be an effective method to improve the quality and efficiency of IDM in several settings, but it remains unknown which factors influence usage of eHealth and change in behavior of patients. Objective Our study, e-Vita COPD, compares different levels of integration of Web-based self-management platforms in IDM in three primary care settings. The main aim of this study is to analyze the factors that successfully promote the use of a self-management platform for COPD patients. Methods The e-Vita COPD study compares three different approaches to incorporating eHealth via Web-based self-management platforms into IDM of COPD using a parallel cohort design. Three groups integrated the platforms to different levels. In groups 1 (high integration) and 2 (medium integration), randomization was performed to two levels of personal assistance for patients (high and low assistance); in group 3 there was no integration into disease management (none integration). Every visit to the e-Vita and Zorgdraad COPD Web platforms was tracked objectively by collecting log data (sessions and services). At the first log-in, patients completed a baseline questionnaire. Baseline characteristics were automatically extracted from the log files including age, gender, education level, scores on the Clinical COPD Questionnaire (CCQ), dyspnea scale (MRC), and quality of life questionnaire (EQ5D). To predict the use of the platforms, multiple linear regression analyses for the different independent variables were performed: integration in IDM (high, medium, none), personal assistance for the participants (high vs low), educational level, and self-efficacy level (General Self-Efficacy Scale [GSES]). All analyses were adjusted for age and gender. Results Of the 702 invited COPD patients, 215 (30.6%) registered to a platform. Of the 82 patients in group 1 (high integration IDM), 36 were in group 1A (personal assistance) and 46 in group 1B (low assistance). Of the 96 patients in group 2 (medium integration IDM), 44 were in group 2A (telephone assistance) and 52 in group 2B (low assistance). A total of 37 patients participated in group 3 (no integration IDM). In all, 107 users (49.8%) visited the platform at least once in the 15-month period. The mean number of sessions differed between the three groups (group 1: mean 10.5, SD 1.3; group 2: mean 8.8, SD 1.4; group 3: mean 3.7, SD 1.8; P=.01). The mean number of sessions differed between the high-assistance and low-assistance groups in groups 1 and 2 (high: mean 11.8, SD 1.3; low: mean 6.7, SD 1.4; F1,80=6.55, P=.01). High-assistance participants used more services (mean 45.4, SD 6.2) than low-assistance participants (mean 21.2, SD 6.8; F1,80=6.82, P=.01). No association was found between educational level and usage and between GSES and usage. Conclusions Use of a self-management platform is higher when participants receive adequate personal assistance about how to use the platform. Blended care, where digital health and usual care are integrated, will likely lead to increased use of the online program. Future research should provide additional insights into the preferences of different patient groups. Trial Registration Nederlands Trial Register NTR4098; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4098 (Archived by WebCite at http://www.webcitation.org/6qO1hqiJ1) PMID:28566268

Comparison of scientific computing platforms for MCNP4A Monte Carlo calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hendricks, J.S.; Brockhoff, R.C.

1994-04-01

The performance of seven computer platforms is evaluated with the widely used and internationally available MCNP4A Monte Carlo radiation transport code. All results are reproducible and are presented in such a way as to enable comparison with computer platforms not in the study. The authors observed that the HP/9000-735 workstation runs MCNP 50% faster than the Cray YMP 8/64. Compared with the Cray YMP 8/64, the IBM RS/6000-560 is 68% as fast, the Sun Sparc10 is 66% as fast, the Silicon Graphics ONYX is 90% as fast, the Gateway 2000 model 4DX2-66V personal computer is 27% as fast, and themore » Sun Sparc2 is 24% as fast. In addition to comparing the timing performance of the seven platforms, the authors observe that changes in compilers and software over the past 2 yr have resulted in only modest performance improvements, hardware improvements have enhanced performance by less than a factor of [approximately]3, timing studies are very problem dependent, MCNP4Q runs about as fast as MCNP4.« less

SiGe BiCMOS manufacturing platform for mmWave applications

NASA Astrophysics Data System (ADS)

Kar-Roy, Arjun; Howard, David; Preisler, Edward; Racanelli, Marco; Chaudhry, Samir; Blaschke, Volker

2010-10-01

TowerJazz offers high volume manufacturable commercial SiGe BiCMOS technology platforms to address the mmWave market. In this paper, first, the SiGe BiCMOS process technology platforms such as SBC18 and SBC13 are described. These manufacturing platforms integrate 200 GHz fT/fMAX SiGe NPN with deep trench isolation into 0.18μm and 0.13μm node CMOS processes along with high density 5.6fF/μm2 stacked MIM capacitors, high value polysilicon resistors, high-Q metal resistors, lateral PNP transistors, and triple well isolation using deep n-well for mixed-signal integration, and, multiple varactors and compact high-Q inductors for RF needs. Second, design enablement tools that maximize performance and lowers costs and time to market such as scalable PSP and HICUM models, statistical and Xsigma models, reliability modeling tools, process control model tools, inductor toolbox and transmission line models are described. Finally, demonstrations in silicon for mmWave applications in the areas of optical networking, mobile broadband, phased array radar, collision avoidance radar and W-band imaging are listed.

Linear phase conjugation for atmospheric aberration compensation

NASA Astrophysics Data System (ADS)

Grasso, Robert J.; Stappaerts, Eddy A.

1998-01-01

Atmospheric induced aberrations can seriously degrade laser performance, greatly affecting the beam that finally reaches the target. Lasers propagated over any distance in the atmosphere suffer from a significant decrease in fluence at the target due to these aberrations. This is especially so for propagation over long distances. It is due primarily to fluctuations in the atmosphere over the propagation path, and from platform motion relative to the intended aimpoint. Also, delivery of high fluence to the target typically requires low beam divergence, thus, atmospheric turbulence, platform motion, or both results in a lack of fine aimpoint control to keep the beam directed at the target. To improve both the beam quality and amount of laser energy delivered to the target, Northrop Grumman has developed the Active Tracking System (ATS); a novel linear phase conjugation aberration compensation technique. Utilizing a silicon spatial light modulator (SLM) as a dynamic wavefront reversing element, ATS undoes aberrations induced by the atmosphere, platform motion or both. ATS continually tracks the target as well as compensates for atmospheric and platform motion induced aberrations. This results in a high fidelity, near-diffraction limited beam delivered to the target.

Integrated nanoscale tools for interrogating living cells

NASA Astrophysics Data System (ADS)

Jorgolli, Marsela

The development of next-generation, nanoscale technologies that interface biological systems will pave the way towards new understanding of such complex systems. Nanowires -- one-dimensional nanoscale structures -- have shown unique potential as an ideal physical interface to biological systems. Herein, we focus on the development of nanowire-based devices that can enable a wide variety of biological studies. First, we built upon standard nanofabrication techniques to optimize nanowire devices, resulting in perfectly ordered arrays of both opaque (Silicon) and transparent (Silicon dioxide) nanowires with user defined structural profile, densities, and overall patterns, as well as high sample consistency and large scale production. The high-precision and well-controlled fabrication method in conjunction with additional technologies laid the foundation for the generation of highly specialized platforms for imaging, electrochemical interrogation, and molecular biology. Next, we utilized nanowires as the fundamental structure in the development of integrated nanoelectronic platforms to directly interrogate the electrical activity of biological systems. Initially, we generated a scalable intracellular electrode platform based on vertical nanowires that allows for parallel electrical interfacing to multiple mammalian neurons. Our prototype device consisted of 16 individually addressable stimulation/recording sites, each containing an array of 9 electrically active silicon nanowires. We showed that these vertical nanowire electrode arrays could intracellularly record and stimulate neuronal activity in dissociated cultures of rat cortical neurons similar to patch clamp electrodes. In addition, we used our intracellular electrode platform to measure multiple individual synaptic connections, which enables the reconstruction of the functional connectivity maps of neuronal circuits. In order to expand and improve the capability of this functional prototype device we designed and fabricated a new hybrid chip that combines a front-side nanowire-based interface for neuronal recording with backside complementary metal oxide semiconductor (CMOS) circuits for on-chip multiplexing, voltage control for stimulation, signal amplification, and signal processing. Individual chips contain 1024 stimulation/recording sites enabling large-scale interfacing of neuronal networks with single cell resolution. Through electrical and electrochemical characterization of the devices, we demonstrated their enhanced functionality at a massively parallel scale. In our initial cell experiments, we achieved intracellular stimulations and recordings of changes in the membrane potential in a variety of cells including: HEK293T, cardiomyocytes, and rat cortical neurons. This demonstrated the device capability for single-cell-resolution recording/stimulation which when extended to a large number of neurons in a massively parallel fashion will enable the functional mapping of a complex neuronal network.

A Ubiquitous Optical Microsystem Platform with Application to Optical Metrology and Chemical Sensing

NASA Astrophysics Data System (ADS)

Gerling, John David

This dissertation is concerned with the development of a novel, versatile optical sensor platform for optical metrology and chemical sensing. We demonstrate the feasibility of embedding optical components between bonded silicon wafers with receptor cavities and optical windows to create a self-contained sensor microsystem that can be used for in-situ measurement of hostile environments. Arrays of these sensors internal to a silicon wafer can enable optical sensing for in-situ, real-time mapping and process development for the semiconductor industry in the form of an instrumented substrate. Single-die versions of these optical sensor platforms can also enable point-of-care diagnostics, high throughput disease screening, bio-warfare agent detection, and environmental monitoring. Our first discussion will focus on a single-wavelength interferometry-based prototype sensor. Several applications are demonstrated using this single wavelength prototype: refractive index monitoring, SiO2 plasma etching, chemical mechanical polishing, photoresist cure and dissolution, copper etch end-point detection, and also nanopore wetting phenomena. Subsequent sections of this dissertation will describe efforts to improve the optical sensor platform to achieve multi-wavelength sensing function. We explore the use of an off-the-shelf commercial RGB sensor for colorimetric monitoring of copper and aluminum thin-film etchings. We then expand upon our prior work and concepts to realize a fully integrated, chip-sized microspectrometer with a photon engine based on a diffraction grating. The design, fabrication, and demonstration of a working prototype with dimensions < 1 mm thick using standard planar microfabrication techniques is described. Proof-of-concept demonstrations indicate the working principle of dispersion, although with a low spectral resolution of 120 nm. With working knowledge of the issues of the first prototype, we present an improved 5-channel microspectrometer with a spectral range 400-900 nm and demonstrate its ability for spectral identification with 3 different phosphor powder samples. Finally, we conclude with suggestions for future areas of research.

Design, fabrication, and characterization of high density silicon photonic components

NASA Astrophysics Data System (ADS)

Jones, Adam Michael

Our burgeoning appetite for data relentlessly demands exponential scaling of computing and communications resources leading to an overbearing and ever-present drive to improve eciency while reducing on-chip area even as photonic components expand to ll application spaces no longer satised by their electronic counterparts. With a high index contrast, low optical loss, and compatibility with the CMOS fabrication infrastructure, silicon-on-insulator technology delivers a mechanism by which ecient, sub-micron waveguides can be fabricated while enabling monolithic integration of photonic components and their associated electronic infrastructure. The result is a solution leveraging the superior bandwidth of optical signaling on a platform capable of delivering the optical analogue to Moore's Law scaling of transistor density. Device size is expected to end Moore's Law scaling in photonics as Maxwell's equations limit the extent to which this parameter may be reduced. The focus of the work presented here surrounds photonic device miniaturization and the development of 3D optical interconnects as approaches to optimize performance in densely integrated optical interconnects. In this dissertation, several technological barriers inhibiting widespread adoption of photonics in data communications and telecommunications are explored. First, examination of loss and crosstalk performance in silicon nitride over SOI waveguide crossings yields insight into the feasibility of 3D optical interconnects with the rst experimental analysis of such a structure presented herein. A novel measurement platform utilizing a modied racetrack resonator is then presented enabling extraction of insertion loss data for highly ecient structures while requiring minimal on-chip area. Finally, pioneering work in understanding the statistical nature of doublet formation in microphotonic resonators is delivered with the resulting impact on resonant device design detailed.

Design Fabrication and Characterization of High Density Silicon Photonic Components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Adam

2015-02-01

Our burgeoning appetite for data relentlessly demands exponential scaling of computing and communications resources leading to an overbearing and ever-present drive to improve e ciency while reducing on-chip area even as photonic components expand to ll application spaces no longer satis ed by their electronic counterparts. With a high index contrast, low optical loss, and compatibility with the CMOS fabrication infrastructure, silicon-on-insulator technology delivers a mechanism by which e cient, sub-micron waveguides can be fabricated while enabling monolithic integration of photonic components and their associated electronic infrastructure. The result is a solution leveraging the superior bandwidth of optical signaling onmore » a platform capable of delivering the optical analogue to Moore's Law scaling of transistor density. Device size is expected to end Moore's Law scaling in photonics as Maxwell's equations limit the extent to which this parameter may be reduced. The focus of the work presented here surrounds photonic device miniaturization and the development of 3D optical interconnects as approaches to optimize performance in densely integrated optical interconnects. In this dissertation, several technological barriers inhibiting widespread adoption of photonics in data communications and telecommunications are explored. First, examination of loss and crosstalk performance in silicon nitride over SOI waveguide crossings yields insight into the feasibility of 3D optical interconnects with the rst experimental analysis of such a structure presented herein. A novel measurement platform utilizing a modi ed racetrack resonator is then presented enabling extraction of insertion loss data for highly e cient structures while requiring minimal on-chip area. Finally, pioneering work in understanding the statistical nature of doublet formation in microphotonic resonators is delivered with the resulting impact on resonant device design detailed.« less

Group Cohesion in Experiential Growth Groups

ERIC Educational Resources Information Center

Steen, Sam; Vasserman-Stokes, Elaina; Vannatta, Rachel

2014-01-01

This article explores the effect of web-based journaling on changes in group cohesion within experiential growth groups. Master's students were divided into 2 groups. Both used a web-based platform to journal after each session; however, only 1 of the groups was able to read each other's journals. Quantitative data collected before and…

Nanoporous Silicon Carbide for Nanoelectromechanical Systems Applications

NASA Technical Reports Server (NTRS)

Hossain, T.; Khan, F.; Adesida, I.; Bohn, P.; Rittenhouse, T.; Lienhard, Michael (Technical Monitor)

2003-01-01

A major goal of this project is to produce porous silicon carbide (PSiC) via an electroless process for eventual utilization in nanoscale sensing platforms. Results in the literature have shown a variety of porous morphologies in SiC produced in anodic cells. Therefore, predictability and reproducibility of porous structures are initial concerns. This work has concentrated on producing morphologies of known porosity, with particular attention paid toward producing the extremely high surface areas required for a porous flow sensor. We have conducted a parametric study of electroless etching conditions and characteristics of the resulting physical nanostructure and also investigated the relationship between morphology and materials properties. Further, we have investigated bulk etching of SiC using both photo-electrochemical etching and inductively-coupled-plasma reactive ion etching techniques.

Dewetting and deposition of thin films with insoluble surfactants from curved silicone hydrogel substrates.

PubMed

Bhamla, M Saad; Balemans, Caroline; Fuller, Gerald G

2015-07-01

We investigate the stabilizing effect of insoluble surfactant monolayers on thin aqueous films. We first describe an experimental platform that enables the formation of aqueous films laden with dipalmitoylphosphatidylcholine (DPPC) monolayers on curved silicone hydrogel (SiHy) substrates. We show that these surfactant layers extend the lifetime of the aqueous films. The films eventually "dewet" by the nucleation and growth of dry areas and the onset of this dewetting can be controlled by the surface rheology of the DPPC layer. We thus demonstrate that increasing the interfacial rheology of the DPPC layer leads to stable films that delay dewetting. We also show that dewetting can be exploited to controllably pattern the underlying curved SiHy substrates with DPPC layers. Copyright © 2015 Elsevier Inc. All rights reserved.

Breather soliton dynamics in microresonators

NASA Astrophysics Data System (ADS)

Yu, Mengjie; Jang, Jae K.; Okawachi, Yoshitomo; Griffith, Austin G.; Luke, Kevin; Miller, Steven A.; Ji, Xingchen; Lipson, Michal; Gaeta, Alexander L.

2017-02-01

The generation of temporal cavity solitons in microresonators results in coherent low-noise optical frequency combs that are critical for applications in spectroscopy, astronomy, navigation or telecommunications. Breather solitons also form an important part of many different classes of nonlinear wave systems, manifesting themselves as a localized temporal structure that exhibits oscillatory behaviour. To date, the dynamics of breather solitons in microresonators remains largely unexplored, and its experimental characterization is challenging. Here we demonstrate the excitation of breather solitons in two different microresonator platforms based on silicon nitride and on silicon. We investigate the dependence of the breathing frequency on pump detuning and observe the transition from period-1 to period-2 oscillation. Our study constitutes a significant contribution to understanding the soliton dynamics within the larger context of nonlinear science.

High ferroelectric polarization in c-oriented BaTiO 3 epitaxial thin films on SrTiO 3/Si(001)

DOE PAGES

Scigaj, M.; Chao, C. H.; Gázquez, J.; ...

2016-09-21

The integration of epitaxial BaTiO 3 films on silicon, combining c-orientation, surface flatness, and high ferroelectric polarization is of main interest towards its use in memory devices. This combination of properties has been only achieved so far by using yttria-stabilized zirconia buffer layers. Here, the all-perovskite BaTiO 3/LaNiO 3/SrTiO 3 heterostructure is grown monolithically on Si(001). The BaTiO 3 films are epitaxial and c-oriented and present low surface roughness and high remnant ferroelectric polarization around 6 μC/cm 2. Lastly, this result paves the way towards the fabrication of lead-free BaTiO 3 ferroelectric memories on silicon platforms.

Ultralow-Loss CMOS Copper Plasmonic Waveguides.

PubMed

Fedyanin, Dmitry Yu; Yakubovsky, Dmitry I; Kirtaev, Roman V; Volkov, Valentyn S

2016-01-13

Surface plasmon polaritons can give a unique opportunity to manipulate light at a scale well below the diffraction limit reducing the size of optical components down to that of nanoelectronic circuits. At the same time, plasmonics is mostly based on noble metals, which are not compatible with microelectronics manufacturing technologies. This prevents plasmonic components from integration with both silicon photonics and silicon microelectronics. Here, we demonstrate ultralow-loss copper plasmonic waveguides fabricated in a simple complementary metal-oxide semiconductor (CMOS) compatible process, which can outperform gold plasmonic waveguides simultaneously providing long (>40 μm) propagation length and deep subwavelength (∼λ(2)/50, where λ is the free-space wavelength) mode confinement in the telecommunication spectral range. These results create the backbone for the development of a CMOS plasmonic platform and its integration in future electronic chips.

Probing the low thermal conductivity of single-crystalline porous Si nanowires

NASA Astrophysics Data System (ADS)

Zhao, Yunshan; Lina Yang Collaboration; Lingyu Kong Collaboration; Baowen Li Collaboration; John T L Thong Collaboration; Kedar Hippalgaonkar Collaboration

Pore-like structures provide a novel way to reduce the thermal conductivity of silicon nanowires, compared to both smooth-surface VLS nanowires and rough EE nanowires. Because of enhanced phonon scattering with interface and decrease in phonon transport path, the porous nanostructures show reduction in thermal conductance by few orders of magnitude. It proves to be extremely challenging to evaluate porosity accurately in an experimental manner and further understand its effect on thermal transport. In this study, we use the newly developed electron-beam based micro-electrothermal device technique to study the porosity dependent thermal conductivity of mesoporous silicon nanowires that have single-crystalline scaffolding. Based on the Casino simulation, the power absorbed by the nanowire, coming from the loss of travelling electron energy, has a linear relationship with it cross section. The relationship has been verified experimentally as well. Monte Carlo simulation is carried out to theoretically predict the thermal conductivity of silicon nanowires with a specific value of porosity. These single-crystalline porous silicon nanowires show extremely low thermal conductivity, even below the amorphous limit. These structures together with our experimental techniques provide a particularly intriguing platform to understand the phonon transport in nanoscale and aid the performance improvement in future nanowires-based devices.

Design and fabrication of a foldable 3D silicon based package for solid state lighting applications

NASA Astrophysics Data System (ADS)

Sokolovskij, R.; Liu, P.; van Zeijl, H. W.; Mimoun, B.; Zhang, G. Q.

2015-05-01

Miniaturization of solid state lighting (SSL) luminaires as well as reduction of packaging and assembly costs are of prime interest for the SSL lighting industry. A novel silicon based LED package for lighting applications is presented in this paper. The proposed design consists of 5 rigid Si tiles connected by flexible polyimide hinges with embedded interconnects (ICs). Electrical, optical and thermal characteristics were taken into consideration during design. The fabrication process involved polyimide (PI) application and patterning, aluminium interconnect integration in the flexible hinge, LED reflector cavity formation and metalization followed by through wafer DRIE etching for chip formation and release. A method to connect chip front to backside without TSVs was also integrated into the process. Post-fabrication wafer level assembly included LED mounting and wirebond, phosphor-based colour conversion and silicone encapsulation. The package formation was finalized by vacuum assisted wrapping around an assembly structure to form a 3D geometry, which is beneficial for omnidirectional lighting. Bending tests were performed on the flexible ICs and optical performance at different temperatures was evaluated. It is suggested that 3D packages can be expanded to platforms for miniaturized luminaire applications by combining monolithic silicon integration and system-in-package (SiP) technologies.

Constructing polyamidoamine dendrons from poly(poly(ethylene glycol) monomethacrylate) brushes grafted from planar silicon hydride surfaces for biomedical applications

NASA Astrophysics Data System (ADS)

Liu, Xiang; Zheng, Hong-Ning; Yan, Qin; Wang, Cuie; Ma, Yin-Zhou; Tang, Yan-Chun; Xiao, Shou-Jun

2011-06-01

A facile approach was established to construct polyamidoamine (PAMAM) dendrons from polymer brushes of poly(poly(ethylene glycol) monomethacrylate) (Si-g-P(PEGMA-OH)) grafted from a planar silicon hydride surface. First the Si-g-P(PEGMA-OH) brushes were grown via surface-initiated atom transfer radical polymerization with robust Si-C links on silicon surfaces. The side-chain hydroxyl groups of Si-g-P(PEGMA-OH) were chlorinated with thionyl chloride and further chlorines were substituted with amino groups of ethylenediamine, giving terminal primary amines. Borrowing the solution synthesis approach, we constructed second and third generations of PAMAM dendrons on-chip by surface-initiated alternative growth of two monomers, methyl acrylate and ethylenediamine. Two applications of silicon-based PAMAM dendrons were shown: the dense amino groups were activated via a cross-linker, N-succinimidyl-6-maleimidylhexanoate, to capture a free-thiol-carrying peptide of oxytocin and the third generation of PAMAM dendrons was used as a platform to on-chip synthesize a three amino acid peptide of Arg-Gly-Asp (RGD). The above conclusions were mainly derived from a home-built multiple transmission-reflection infrared spectroscopy, and complemented by X-ray photoelectron spectroscopy, UV-Vis spectroscopy and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry.

Chemical Interaction-Guided, Metal-Free Growth of Large-Area Hexagonal Boron Nitride on Silicon-Based Substrates.

PubMed

Behura, Sanjay; Nguyen, Phong; Debbarma, Rousan; Che, Songwei; Seacrist, Michael R; Berry, Vikas

2017-05-23

Hexagonal boron nitride (h-BN) is an ideal platform for interfacing with two-dimensional (2D) nanomaterials to reduce carrier scattering for high-quality 2D electronics. However, scalable, transfer-free growth of hexagonal boron nitride (h-BN) remains a challenge. Currently, h-BN-based 2D heterostructures require exfoliation or chemical transfer of h-BN grown on metals resulting in small areas or significant interfacial impurities. Here, we demonstrate a surface-chemistry-influenced transfer-free growth of large-area, uniform, and smooth h-BN directly on silicon (Si)-based substrates, including Si, silicon nitride (Si 3 N 4 ), and silicon dioxide (SiO 2 ), via low-pressure chemical vapor deposition. The growth rates increase with substrate electronegativity, Si < Si 3 N 4 < SiO 2 , consistent with the adsorption rates calculated for the precursor molecules via atomistic molecular dynamics simulations. Under graphene with high grain density, this h-BN film acts as a polymer-free, planar-dielectric interface increasing carrier mobility by 3.5-fold attributed to reduced surface roughness and charged impurities. This single-step, chemical interaction guided, metal-free growth mechanism of h-BN for graphene heterostructures establishes a potential pathway for the design of complex and integrated 2D-heterostructured circuitry.

VCSEL Scaling, Laser Integration on Silicon, and Bit Energy

DTIC Science & Technology

2017-03-01

need of high efficiency with high temperature operation eliminates essentially all laser diode technologies except VCSELs. Therefore scaling of the...CW laser diode and separate modulator. Lower diagram circuitry shows the case for a DML VCSEL. The small gain volume and high speed modulation...speed of the modulator. However the CW laser that is needed for the modulator appears to create a technological roadblock for laser diode platforms

All-Printed Flexible and Stretchable Electronics.

PubMed

Mohammed, Mohammed G; Kramer, Rebecca

2017-05-01

A fully automated additive manufacturing process that produces all-printed flexible and stretchable electronics is demonstrated. The printing process combines soft silicone elastomer printing and liquid metal processing on a single high-precision 3D stage. The platform is capable of fabricating extremely complex conductive circuits, strain and pressure sensors, stretchable wires, and wearable circuits with high yield and repeatability. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

On-chip integration of suspended InGaN/GaN multiple-quantum-well devices with versatile functionalities.

PubMed

Cai, Wei; Yang, Yongchao; Gao, Xumin; Yuan, Jialei; Yuan, Wei; Zhu, Hongbo; Wang, Yongjin

2016-03-21

We propose, fabricate and demonstrate on-chip photonic integration of suspended InGaN/GaN multiple quantum wells (MQWs) devices on the GaN-on-silicon platform. Both silicon removal and back wafer etching are conducted to obtain membrane-type devices, and suspended waveguides are used for the connection between p-n junction InGaN/GaN MQWs devices. As an in-plane data transmission system, the middle p-n junction InGaN/GaN MQWs device is used as a light emitting diode (LED) to deliver signals by modulating the intensity of the emitted light, and the other two devices act as photodetectors (PDs) to sense the light guided by the suspended waveguide and convert the photons into electrons, achieving 1 × 2 in-plane information transmission via visible light. Correspondingly, the three devices can function as independent PDs to realize multiple receivers for free space visible light communication. Further, the on-chip photonic platform can be used as an active electro-optical sensing system when the middle device acts as a PD and the other two devices serve as LEDs. The experimental results show that the auxiliary LED sources can enhance the amplitude of the induced photocurrent.

Fabrication and characterization of a chemically oxidized-nanostructured porous silicon based biosensor implementing orienting protein A.

PubMed

Naveas, Nelson; Hernandez-Montelongo, Jacobo; Pulido, Ruth; Torres-Costa, Vicente; Villanueva-Guerrero, Raúl; Predestinación García Ruiz, Josefa; Manso-Silván, Miguel

2014-03-01

Nanostructured porous silicon (PSi) elicits as a very attractive material for future biosensing systems due to its high surface area, biocompatibility and well-established fabrication methods. In order to engineer its performance as a biosensor transducer platform, the density of immunoglobulins properly immobilized and oriented onto the surface needs to be optimized. In this work we fabricated and characterized a novel biosensing system focusing on the improvement of the biofunctionalization cascade. The system consists on a chemically oxidized PSi platform derivatized with 3-aminopropyltriethoxysilane (APTS) that is coupled to Staphylococcus protein A (SpA). The chemical oxidation has previously demonstrated to enhance the biofunctionalization process and here "by implementing SpA" a molecularly oriented immunosensor is achieved. The biosensor system is characterized in terms of its chemical composition, wettability and optical reflectance. Finally, this system is successfully exploited to develop a biosensor for detecting asymmetric dimethylarginine (ADMA), an endogenous molecule involved in cardiovascular diseases. Therefore, this work is relevant from the point of view of design and optimization of the biomolecular immobilization cascade on PSi surfaces with the added value of contribution to the development of new assays for detecting ADMA with a view on prevention of cardiovascular diseases. Copyright © 2013 Elsevier B.V. All rights reserved.

Novel nanoplasmonic biosensor integrated in a microfluidic channel

NASA Astrophysics Data System (ADS)

Solis-Tinoco, V.; Sepulveda, B.; Lechuga, L. M.

2015-06-01

An important motivation of the actual biosensor research is to develop a multiplexed sensing platform of high sensitivity fabricated with large-scale and low-cost technologies for applications such as diagnosis and monitoring of diseases, drug discovery and environmental control. Biosensors based on localized plasmon resonance (LSPR) have demonstrated to be a novel and effective platform for quantitative detection of biological and chemical analytes. Here, we describe a novel label-free nanobiosensor consisting of an array of closely spaced, vertical, elastomeric nanopillars capped with plasmonic gold nanodisks in a SU-8 channel. The principle is based on the refractive index sensing using the LSPR of gold nanodisks. The fabrication of the nanobiosensor is based on replica molding technique and gold nanodisks are incorporated on the polymer structures by e-beam evaporation. In this work, we provide the strategies for controlling the silicon nanostructure replication using thermal polymers and photopolymers with different Young's modulus, in order to minimize the common distortions in the process and to obtain a reliable replica of the Si master. The master mold of the biosensor consists of a hexagonal array of silicon nanopillars, whose diameter is ~200 nm, and whose height can range from 250 nm to 1.300 μm, separated 400 nm from the center to center, integrated in a SU-8 microfluidic channel.

Synergistically Enhanced Performance of Ultrathin Nanostructured Silicon Solar Cells Embedded in Plasmonically Assisted, Multispectral Luminescent Waveguides.

PubMed

Lee, Sung-Min; Dhar, Purnim; Chen, Huandong; Montenegro, Angelo; Liaw, Lauren; Kang, Dongseok; Gai, Boju; Benderskii, Alexander V; Yoon, Jongseung

2017-04-25

Ultrathin silicon solar cells fabricated by anisotropic wet chemical etching of single-crystalline wafer materials represent an attractive materials platform that could provide many advantages for realizing high-performance, low-cost photovoltaics. However, their intrinsically limited photovoltaic performance arising from insufficient absorption of low-energy photons demands careful design of light management to maximize the efficiency and preserve the cost-effectiveness of solar cells. Herein we present an integrated flexible solar module of ultrathin, nanostructured silicon solar cells capable of simultaneously exploiting spectral upconversion and downshifting in conjunction with multispectral luminescent waveguides and a nanostructured plasmonic reflector to compensate for their weak optical absorption and enhance their performance. The 8 μm-thick silicon solar cells incorporating a hexagonally periodic nanostructured surface relief are surface-embedded in layered multispectral luminescent media containing organic dyes and NaYF 4 :Yb 3+ ,Er 3+ nanocrystals as downshifting and upconverting luminophores, respectively, via printing-enabled deterministic materials assembly. The ultrathin nanostructured silicon microcells in the composite luminescent waveguide exhibit strongly augmented photocurrent (∼40.1 mA/cm 2 ) and energy conversion efficiency (∼12.8%) than devices with only a single type of luminescent species, owing to the synergistic contributions from optical downshifting, plasmonically enhanced upconversion, and waveguided photon flux for optical concentration, where the short-circuit current density increased by ∼13.6 mA/cm 2 compared with microcells in a nonluminescent medium on a plain silver reflector under a confined illumination.

Synergistically Enhanced Performance of Ultrathin Nanostructured Silicon Solar Cells Embedded in Plasmonically Assisted, Multispectral Luminescent Waveguides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Sung-Min; Dhar, Purnim; Chen, Huandong

Ultrathin silicon solar cells fabricated by anisotropic wet chemical etching of single-crystalline wafer materials represent an attractive materials platform that could provide many advantages for realizing high-performance, low-cost photovoltaics. However, their intrinsically limited photovoltaic performance arising from insufficient absorption of low-energy photons demands careful design of light management to maximize the efficiency and preserve the cost-effectiveness of solar cells. Herein we present an integrated flexible solar module of ultrathin, nanostructured silicon solar cells capable of simultaneously exploiting spectral upconversion and downshifting in conjunction with multispectral luminescent waveguides and a nanostructured plasmonic reflector to compensate for their weak optical absorption andmore » enhance their performance. The 8 μm-thick silicon solar cells incorporating a hexagonally periodic nanostructured surface relief are surface-embedded in layered multispectral luminescent media containing organic dyes and NaYF4:Yb3+,Er3+ nanocrystals as downshifting and upconverting luminophores, respectively, via printing-enabled deterministic materials assembly. The ultrathin nanostructured silicon microcells in the composite luminescent waveguide exhibit strongly augmented photocurrent (~40.1 mA/cm2) and energy conversion efficiency (~12.8%) than devices with only a single type of luminescent species, owing to the synergistic contributions from optical downshifting, plasmonically enhanced upconversion, and waveguided photon flux for optical concentration, where the short-circuit current density increased by ~13.6 mA/cm2 compared with microcells in a nonluminescent medium on a plain silver reflector under a confined illumination.« less

Whole body vibration improves cognition in healthy young adults.

PubMed

Regterschot, G Ruben H; Van Heuvelen, Marieke J G; Zeinstra, Edzard B; Fuermaier, Anselm B M; Tucha, Lara; Koerts, Janneke; Tucha, Oliver; Van Der Zee, Eddy A

2014-01-01

This study investigated the acute effects of passive whole body vibration (WBV) on executive functions in healthy young adults. Participants (112 females, 21 males; age: 20.5±2.2 years) underwent six passive WBV sessions (frequency 30 Hz, amplitude approximately 0.5 mm) and six non-vibration control sessions of two minutes each while sitting on a chair mounted on a vibrating platform. A passive WBV session was alternated with a control session. Directly after each session, performance on the Stroop Color-Block Test (CBT), Stroop Color-Word Interference Test (CWIT), Stroop Difference Score (SDS) and Digit Span Backward task (DSBT) was measured. In half of the passive WBV and control sessions the test order was CBT-CWIT-DSBT, and DSBT-CBT-CWIT in the other half. Passive WBV improved CWIT (p = 0.009; effect size r = 0.20) and SDS (p = 0.034; r = 0.16) performance, but only when the CBT and CWIT preceded the DSBT. CBT and DSBT performance did not change. This study shows that two minutes passive WBV has positive acute effects on attention and inhibition in young adults, notwithstanding their high cognitive functioning which could have hampered improvement. This finding indicates the potential of passive WBV as a cognition-enhancing therapy worth further evaluation, especially in persons unable to perform active forms of exercise.

Acceptance of mixed scientific and clinical activities in a sub-speciality urology meeting.

PubMed

Buchholz, Noor N P; El Howairis, Mohammed El Fatih; Durner, Leopold; Harry, Damiete; Kachrilas, Stefanos; Rodgers, Allen L; Hakenberg, Oliver

2015-04-01

Basic urolithiasis research into the causes for stone formation has been stagnating for a long time. Emergence of effective stone treatment modalities has shifted the public and clinicians' focus away from basic research towards symptomatic treatment solutions. This has occurred in spite of urolithiasis being a highly recurrent disease with an enormous socio-economic impact warranting a prophylactic and recurrence-preventing approach. An integrated, multidisciplinary translational platform has been developed in the form of urolithiasis meetings bringing together urologists, radiologists, nephrologists, basic scientists, dieticians and other stake holders interested in stone disease, for an exchange of knowledge, mutual education and understanding, and professional networking. Traditionally, such combined meetings are split into sessions addressing the specific interests of clinicians and scientists. At the recent Experts in Stone Disease Symposium we devised and implemented a program which mixed clinical and basic science activities throughout. We interviewed delegates between sessions regarding their acceptance of this novel concept using a standardized questionnaire. Sessions were well-attended, alleviating our initial anxiety that delegates would not appreciate a "no-choice" program. Of the 74 delegates who were interviewed, 60 (81%) were urologists, and 14 (19%) were non-urologists such as nephrologists, dieticians, and students. This is representative of the overall distribution of delegates at the conference. 71% felt that a closer co-operation and understanding between clinicians and scientists will ultimately benefit both groups, as well as patients; 95% found the mixed session approach beneficial, with half appreciating it as very good and innovative; 94% believed that they had derived useful learnings from the "other side"; 94% found that such mixed sessions are useful for their future work and understanding of the urolithiasis field as a whole; 94% agreed that mixed meetings of this type are useful in enhancing networking between the different stake holders in urolithiasis treatment and research. Finally, 85% would like to visit future mixed session meetings, and 89% would encourage their juniors to attend, too. Not only was a platform created to facilitate multidisciplinary exchange and networking, but delegates from several different backgrounds were encouraged to attend presentations in disciplines other than their own. The results of our survey confirm an overwhelmingly positive acceptance of this integrated multidisciplinary concept for stone meetings. As such, we are encouraged to continue with this concept in future conferences.

Multilayered photonic integration on SOI platform using waveguide-based bridge structure

NASA Astrophysics Data System (ADS)

Majumder, Saikat; Chakraborty, Rajib

2018-06-01

A waveguide based structure on silicon on insulator platform is proposed for vertical integration in photonic integrated circuits. The structure consists of two multimode interference couplers connected by a single mode (SM) section which can act as a bridge over any other underlying device. Two more SM sections acts as input and output of the first and second multimode couplers respectively. Potential application of this structure is in multilayered photonic links. It is shown that the efficiency of the structure can be improved by making some design modifications. The entire simulation is done using effective-index based matrix method. The feature size chosen are comparable to waveguides fabricated previously so as to fabricate the proposed structure easily.

[Clinical experiences after implantation of various lens types in silicon oil tamponade].

PubMed

Effert, R; Lommatzsch, A; Wessing, A

1996-06-01

A tamponade of the vitreous space with silicone oil will obligatory lead to cataract after 6 to 12 months. Today it is easily possible, to implant an artificial lense in silicone oil filled eyes. However the combination of an artificial lense and silicone oil will lead to a strong inflammation in the anterior segment of the eye. 22 pseudophacic patients with silicone oil tamponade were examined 2 to 6 months after the operation. In 12 patients simple artificial lenses were implanted, in 10 patients heparin modified lenses were implanted. In 10 cases the lens was implanted followed by the insufflation of silicone oil in the vitreous cavity, in 2 cases a lens was implanted in a silicone oil filled eye and the silicon oil was not removed. In 8 cases the implantation of the artificial lens has been performed some months to years before the insufflation of the silicone oil. The indication for the silicon oil tamponade was a PVR retinal detachment in all cases. The following parameters were examined: Reaction of the pupil to light, pupil round or oval in miosis, examination of the fundus peripherie possible after mydriasis, fixation of the iris with parts of the capsula or with the anterior surface of the lens? In addition in 12 cases the postoperative refraction was compared with the results of the biometry, which was performed before the operation. In the cases with a simple lens in about 50% an incomplete miosis or an oval pupil because of fixation of the iris with parts of the capsula or with the anterior surface of the lense could be observed. In the cases with heparin modified lenses these complications could be observed in 20%. In all cases a strong opacification of the capsula was seen. In 8 of 12 cases with combined procedure a small hyperopia was measured, in 4 cases a large deviation was measured. The implantation of an artificial lens in silicone oil filled eyes is an alternative to the aphacic status with an Ando Iridectomy. Obviously heparin modified lenses have advantages in these cases. Because of the strong cataract formation we suggest to remove the anterior and the posterior capsula in the first operative session and to implant the haptics of the lens into the sulcus. Because of the high rate of complications generally first a stable retina condition should be reached before the implanation of an artificial lens is performed.

Effects of a dragonfly (Anax i.) homeopathic remedy on learning, memory and cell morphology in mice.

PubMed

Mutlu, Oguz; Ulak, Guner; Kokturk, Sibel; Komsuoglu Celikyurt, Ipek; Tanyeri, Pelin; Akar, Furuzan; Erden, Faruk

2016-02-01

Homeopathy is a form of alternative medicine in which uses highly diluted preparations that are believed to cause healthy people to exhibit symptoms similar to those exhibited by patients. The aim of this study was to investigate the effects of dragonfly (Anax imperator, Anax i.) on learning and memory in naive mice using the Morris water maze (MWM) test; moreover, the effects of dragonfly on MK-801-induced cognitive dysfunction were evaluated. Male balb-c mice were treated with dragonfly (30C and 200C) or MK-801 (0.2 mg/kg) alone or concurrently (n = 10). Dragonfly (D) and MK-801 were administered subchronically for 6 days intraperitoneally 60 min and 30 min, respectively, before the daily performance of the MWM test. This study revealed that in the familiarization session and first session of the MWM test, Anax i. D30 significantly decreased escape latency compared to the control group, although MK-801, D30 and D200 significantly increased escape latency at the end of five acquisition sessions. Anax i. combined with dizocilpine maleate (MK-801) also significantly decreased escape latency in the familiarization session and first session of the MWM test, although this combination increased escape latency compared to the MK-801 alone group at the end of the test. Time spent in escape platform's quadrant in the probe trial significantly decreased while mean distance to platform significantly increased in MK-801, D30 and D200 groups. In the MWM test, Anax i. combined with MK-801 significantly decreased speed of the animals compared to the MK-801 alone group. General cell morphology was disturbed in the MK-801 group while D30 and D200 seemed to improve cell damage in the MK-801 group. These results suggest that the homeopathic Anax i. can impair learning acquisition and reference memory, and it has beneficial effects on disturbed cell morphology. Copyright © 2015 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Do swimming goggles limit microbial contamination of contact lenses?

PubMed

Wu, Yvonne T; Tran, Jess; Truong, Michelle; Harmis, Najat; Zhu, Hua; Stapleton, Fiona

2011-04-01

Wearing goggles over contact lenses while swimming is often recommended by eye care professionals. Limited data are available to assess this recommendation. The purpose of this study was to examine whether wearing goggles while swimming limits bacterial colonization on contact lenses and whether the type of lens worn affects contamination rates. Twenty-three subjects underwent two swimming sessions at an ocean (salt water) pool (Maroubra beach Rock Pool, Sydney, Australia). Silicone hydrogel (Ciba Focus Night and Day) or hydrogel lenses (Ciba Focus Daily) were inserted into subjects' eyes before 30 min of swimming sessions, and subjects used modified goggles to mimic goggled and non-goggled conditions. At the end of each session, lenses were collected for microbial investigation. Viable bacterial colonies were classified as gram positive and gram negative and enumerated. The level of bacterial colonization on contact lenses between goggled and non-goggled conditions and between the two lens materials were compared. The range of colony forming units recovered from goggled lenses were 0 to 930 compared with 0 to 1210 on non-goggled lenses. The majority of subjects (16/23) had more microorganisms in the non-goggled condition than when wearing goggles (p = 0.03). Gram negative organisms were found in three non-goggled lenses. No significant difference was shown in the number of bacteria isolated from silicone hydrogel and hydrogel lenses (p > 0.6) irrespective of wearing goggles. Water samples had consistently higher numbers of bacterial counts than those adhered to the lenses; however, no association was found between the number of bacteria in the water sample and those found on the contact lenses. Consistently, fewer bacterial colonies were found on the goggled contact lens, thus suggesting goggles offer some protection against bacterial colonization of contact lenses while swimming. These data would support the recommendation encouraging lens wearers to use goggles while swimming.

A pilot study of surgical training using a virtual robotic surgery simulator.

PubMed

Tergas, Ana I; Sheth, Sangini B; Green, Isabel C; Giuntoli, Robert L; Winder, Abigail D; Fader, Amanda N

2013-01-01

Our objectives were to compare the utility of learning a suturing task on the virtual reality da Vinci Skills Simulator versus the da Vinci Surgical System dry laboratory platform and to assess user satisfaction among novice robotic surgeons. Medical trainees were enrolled prospectively; one group trained on the virtual reality simulator, and the other group trained on the da Vinci dry laboratory platform. Trainees received pretesting and post-testing on the dry laboratory platform. Participants then completed an anonymous online user experience and satisfaction survey. We enrolled 20 participants. Mean pretest completion times did not significantly differ between the 2 groups. Training with either platform was associated with a similar decrease in mean time to completion (simulator platform group, 64.9 seconds [P = .04]; dry laboratory platform group, 63.9 seconds [P < .01]). Most participants (58%) preferred the virtual reality platform. The majority found the training "definitely useful" in improving robotic surgical skills (mean, 4.6) and would attend future training sessions (mean, 4.5). Training on the virtual reality robotic simulator or the dry laboratory robotic surgery platform resulted in significant improvements in time to completion and economy of motion for novice robotic surgeons. Although there was a perception that both simulators improved performance, there was a preference for the virtual reality simulator. Benefits unique to the simulator platform include autonomy of use, computerized performance feedback, and ease of setup. These features may facilitate more efficient and sophisticated simulation training above that of the conventional dry laboratory platform, without loss of efficacy.

Optical fiber Bragg grating-instrumented silicone liner for interface pressure measurement within prosthetic sockets of lower-limb amputees

NASA Astrophysics Data System (ADS)

Al-Fakih, Ebrahim; Arifin, Nooranida; Pirouzi, Gholamhossein; Mahamd Adikan, Faisal Rafiq; Shasmin, Hanie Nadia; Abu Osman, Noor Azuan

2017-08-01

This paper presents a fiber Bragg grating (FBG)-instrumented prosthetic silicone liner that provides cushioning for the residual limb and can successfully measure interface pressures inside prosthetic sockets of lower-limb amputees in a simple and practical means of sensing. The liner is made of two silicone layers between which 12 FBG sensors were embedded at locations of clinical interest. The sensors were then calibrated using a custom calibration platform that mimics a real-life situation. Afterward, a custom gait simulating machine was built to test the liner performance during an amputee's simulated gait. To validate the findings, the results were compared to those obtained by the commonly used F-socket mats. As the statistical findings reveal, both pressure mapping methods measured the interface pressure in a consistent way, with no significant difference (P-values ≥0.05). This pressure mapping technique in the form of a prosthetic liner will allow prosthetics professionals to quickly and accurately create an overall picture of the interface pressure distribution inside sockets in research and clinical settings, thereby improving the socket fit and amputee's satisfaction.

Optical modulation techniques for analog signal processing and CMOS compatible electro-optic modulation

NASA Astrophysics Data System (ADS)

Gill, Douglas M.; Rasras, Mahmoud; Tu, Kun-Yii; Chen, Young-Kai; White, Alice E.; Patel, Sanjay S.; Carothers, Daniel; Pomerene, Andrew; Kamocsai, Robert; Beattie, James; Kopa, Anthony; Apsel, Alyssa; Beals, Mark; Mitchel, Jurgen; Liu, Jifeng; Kimerling, Lionel C.

2008-02-01

Integrating electronic and photonic functions onto a single silicon-based chip using techniques compatible with mass-production CMOS electronics will enable new design paradigms for existing system architectures and open new opportunities for electro-optic applications with the potential to dramatically change the management, cost, footprint, weight, and power consumption of today's communication systems. While broadband analog system applications represent a smaller volume market than that for digital data transmission, there are significant deployments of analog electro-optic systems for commercial and military applications. Broadband linear modulation is a critical building block in optical analog signal processing and also could have significant applications in digital communication systems. Recently, broadband electro-optic modulators on a silicon platform have been demonstrated based on the plasma dispersion effect. The use of the plasma dispersion effect within a CMOS compatible waveguide creates new challenges and opportunities for analog signal processing since the index and propagation loss change within the waveguide during modulation. We will review the current status of silicon-based electrooptic modulators and also linearization techniques for optical modulation.

Fully Tunable Silicon Nanowire Arrays Fabricated by Soft Nanoparticle Templating.

PubMed

Rey, By Marcel; Elnathan, Roey; Ditcovski, Ran; Geisel, Karen; Zanini, Michele; Fernandez-Rodriguez, Miguel-Angel; Naik, Vikrant V; Frutiger, Andreas; Richtering, Walter; Ellenbogen, Tal; Voelcker, Nicolas H; Isa, Lucio

2016-01-13

We demonstrate a fabrication breakthrough to produce large-area arrays of vertically aligned silicon nanowires (VA-SiNWs) with full tunability of the geometry of the single nanowires and of the whole array, paving the way toward advanced programmable designs of nanowire platforms. At the core of our fabrication route, termed "Soft Nanoparticle Templating", is the conversion of gradually compressed self-assembled monolayers of soft nanoparticles (microgels) at a water-oil interface into customized lithographical masks to create VA-SiNW arrays by means of metal-assisted chemical etching (MACE). This combination of bottom-up and top-down techniques affords excellent control of nanowire etching site locations, enabling independent control of nanowire spacing, diameter and height in a single fabrication route. We demonstrate the fabrication of centimeter-scale two-dimensional gradient photonic crystals exhibiting continuously varying structural colors across the entire visible spectrum on a single silicon substrate, and the formation of tunable optical cavities supported by the VA-SiNWs, as unambiguously demonstrated through numerical simulations. Finally, Soft Nanoparticle Templating is combined with optical lithography to create hierarchical and programmable VA-SiNW patterns.

Hydrogen adsorption in metal-decorated silicon carbide nanotubes

NASA Astrophysics Data System (ADS)

Singh, Ram Sevak; Solanki, Ankit

2016-09-01

Hydrogen storage for fuel cell is an active area of research and appropriate materials with excellent hydrogen adsorption properties are highly demanded. Nanotubes, having high surface to volume ratio, are promising storage materials for hydrogen. Recently, silicon carbide nanotubes have been predicted as potential materials for future hydrogen storage application, and studies in this area are ongoing. Here, we report a systematic study on hydrogen adsorption properties in metal (Pt, Ni and Al) decorated silicon carbide nanotubes (SiCNTs) using first principles calculations based on density functional theory. The hydrogen adsorption properties are investigated by calculations of adsorption energy, electronic band structure, density of states (DOS) and Mulliken charge population analysis. Our findings show that hydrogen adsorptions on Pt, Ni and Al-decorated SiCNTs undergo spontaneous exothermic reactions with significant modulation of electronic structure of SiCNTs in all cases. Importantly, according to the Mulliken charge population analysis, dipole-dipole interaction causes chemisorptions of hydrogen in Pt, Ni and Al decorated SiCNTs with formation of chemical bonds. The study is a platform for the development of metal decorated SiCNTs for hydrogen adsorption or hydrogen storage application.

Nucleation and atomic layer reaction in nickel silicide for defect-engineered Si nanochannels.

PubMed

Tang, Wei; Picraux, S Tom; Huang, Jian Yu; Gusak, Andriy M; Tu, King-Ning; Dayeh, Shadi A

2013-06-12

At the nanoscale, defects can significantly impact phase transformation processes and change materials properties. The material nickel silicide has been the industry standard electrical contact of silicon microelectronics for decades and is a rich platform for scientific innovation at the conjunction of materials and electronics. Its formation in nanoscale silicon devices that employ high levels of strain, intentional, and unintentional twins or grain boundaries can be dramatically different from the commonly conceived bulk processes. Here, using in situ high-resolution transmission electron microscopy (HRTEM), we capture single events during heterogeneous nucleation and atomic layer reaction of nickel silicide at various crystalline boundaries in Si nanochannels for the first time. We show through systematic experiments and analytical modeling that unlike other typical face-centered cubic materials such as copper or silicon the twin defects in NiSi2 have high interfacial energies. We observe that these twin defects dramatically change the behavior of new phase nucleation and can have direct implications for ultrascaled devices that are prone to defects or may utilize them to improve device performance.

Extended Hubbard model for mesoscopic transport in donor arrays in silicon

NASA Astrophysics Data System (ADS)

Le, Nguyen H.; Fisher, Andrew J.; Ginossar, Eran

2017-12-01

Arrays of dopants in silicon are promising platforms for the quantum simulation of the Fermi-Hubbard model. We show that the simplest model with only on-site interaction is insufficient to describe the physics of an array of phosphorous donors in silicon due to the strong intersite interaction in the system. We also study the resonant tunneling transport in the array at low temperature as a mean of probing the features of the Hubbard physics, such as the Hubbard bands and the Mott gap. Two mechanisms of localization which suppresses transport in the array are investigated: The first arises from the electron-ion core attraction and is significant at low filling; the second is due to the sharp oscillation in the tunnel coupling caused by the intervalley interference of the donor electron's wave function. This disorder in the tunnel coupling leads to a steep exponential decay of conductance with channel length in one-dimensional arrays, but its effect is less prominent in two-dimensional ones. Hence, it is possible to observe resonant tunneling transport in a relatively large array in two dimensions.

PREFACE: International Scientific Conference of Young Scientists: Advanced Materials in Construction and Engineering (TSUAB2014)

NASA Astrophysics Data System (ADS)

Kopanitsa, Natalia O.

2015-01-01

In October 15-17, 2014 International Scientific Conference of Young Scientists: Advanced Materials in Construction and Engineering (TSUAB2014) took place at Tomsk State University of Architecture and Building (Tomsk, Russia). The Conference became a discussion platform for researchers in the fields of studying structure and properties of advanced building materials and included open lectures of leading scientists and oral presentations of master, postgraduate and doctoral students. A special session was devoted to reports of school children who further plan on starting a research career. The Conference included an industrial exhibition where companies displayed the products and services they supply. The companies also gave presentations of their products within the Conference sessions.

Wurtzite-Phased InP Micropillars Grown on Silicon with Low Surface Recombination Velocity.

PubMed

Li, Kun; Ng, Kar Wei; Tran, Thai-Truong D; Sun, Hao; Lu, Fanglu; Chang-Hasnain, Connie J

2015-11-11

The direct growth of III-V nanostructures on silicon has shown great promise in the integration of optoelectronics with silicon-based technologies. Our previous work showed that scaling up nanostructures to microsize while maintaining high quality heterogeneous integration opens a pathway toward a complete photonic integrated circuit and high-efficiency cost-effective solar cells. In this paper, we present a thorough material study of novel metastable InP micropillars monolithically grown on silicon, focusing on two enabling aspects of this technology-the stress relaxation mechanism at the heterogeneous interface and the microstructure surface quality. Aberration-corrected transmission electron microscopy studies show that InP grows directly on silicon without any amorphous layer in between. A set of periodic dislocations was found at the heterointerface, relaxing the 8% lattice mismatch between InP and Si. Single crystalline InP therefore can grow on top of the fully relaxed template, yielding high-quality micropillars with diameters expanding beyond 1 μm. An interesting power-dependence trend of carrier recombination lifetimes was captured for these InP micropillars at room temperature, for the first time for micro/nanostructures. By simply combining internal quantum efficiency with carrier lifetime, we revealed the recombination dynamics of nonradiative and radiative portions separately. A very low surface recombination velocity of 1.1 × 10(3) cm/sec was obtained. In addition, we experimentally estimated the radiative recombination B coefficient of 2.0 × 10(-10) cm(3)/sec for pure wurtzite-phased InP. These values are comparable with those obtained from InP bulk. Exceeding the limits of conventional nanowires, our InP micropillars combine the strengths of both nanostructures and bulk materials and will provide an avenue in heterogeneous integration of III-V semiconductor materials onto silicon platforms.

Driving electromechanically assisted Gait Trainer for people with stroke.

PubMed

Iosa, Marco; Morone, Giovanni; Bragoni, Maura; De Angelis, Domenico; Venturiero, Vincenzo; Coiro, Paola; Pratesi, Luca; Paolucci, Stefano

2011-01-01

Electromechanically assisted gait training is a promising task-oriented approach for gait restoration, especially for people with subacute stroke. However, few guidelines are available for selecting the parameter values of the electromechanical Gait Trainer (GT) (Reha-Stim; Berlin, Germany) and none is tailored to a patient's motor capacity. We assessed 342 GT sessions performed by 20 people with stroke who were stratified by Functional Ambulatory Category. In the first GT session of all patients, the body-weight support (BWS) required was higher than that reported in the literature. In further sessions, we noted a slow reduction of BWS and a fast increment of walking speed for the most-affected patients. Inverse trends were observed for the less-affected patients. In all the patients, the heart rate increment was about 20 beats per minute, even for sessions in which the number of strides performed was up to 500. In addition, the effective BWS measured during GT sessions was different from that initially selected by the physiotherapist. This difference depended mainly on the position of the GT platforms during selection. Finally, harness acceleration in the anteroposterior direction proved to be higher in patients with stroke than in nondisabled subjects. Our findings are an initial step toward scientifically selecting parameters in electromechanically assisted gait training.

Glia protein aquaporin-4 regulates aversive motivation of spatial memory in Morris water maze.

PubMed

Zhang, Ji; Li, Ying; Chen, Zhong-Guo; Dang, Hui; Ding, Jian-Hua; Fan, Yi; Hu, Gang

2013-12-01

Although extensive investigation has revealed that an astrocyte-specific protein aquaporin-4 (AQP4) participates in regulating synaptic plasticity and memory, a functional relationship between AQP4 and learning processing has not been clearly established. This study was designed to test our hypothesis that AQP4 modulates the aversive motivation in Morris water maze (MWM). Using hidden platform training, we observed that AQP4 KO mice significantly decreased their swimming velocity compared with wild-type (WT) mice. To test for a relationship between velocities and escape motivation, we removed the platform and subjected a new group of mice similar to the session of hidden platform training. We found that KO mice exhibited a gradual reduction in swimming velocity, while WT mice did not alter their velocity. In the subsequent probe trial, KO mice after no platform training significantly decreased their mean velocity compared with those KO mice after hide platform training. However, all of KO mice were not impaired in their ability to locate a visible, cued escape platform. Our findings, along with a previous report that AQP4 regulates memory consolidation, implicate a novel role for this glial protein in modulating the aversive motivation in spatial learning paradigm. © 2013 John Wiley & Sons Ltd.

Robust integration schemes for junction-based modulators in a 200mm CMOS compatible silicon photonic platform (Conference Presentation)

NASA Astrophysics Data System (ADS)

Szelag, Bertrand; Abraham, Alexis; Brision, Stéphane; Gindre, Paul; Blampey, Benjamin; Myko, André; Olivier, Segolene; Kopp, Christophe

2017-05-01

Silicon photonic is becoming a reality for next generation communication system addressing the increasing needs of HPC (High Performance Computing) systems and datacenters. CMOS compatible photonic platforms are developed in many foundries integrating passive and active devices. The use of existing and qualified microelectronics process guarantees cost efficient and mature photonic technologies. Meanwhile, photonic devices have their own fabrication constraints, not similar to those of cmos devices, which can affect their performances. In this paper, we are addressing the integration of PN junction Mach Zehnder modulator in a 200mm CMOS compatible photonic platform. Implantation based device characteristics are impacted by many process variations among which screening layer thickness, dopant diffusion, implantation mask overlay. CMOS devices are generally quite robust with respect to these processes thanks to dedicated design rules. For photonic devices, the situation is different since, most of the time, doped areas must be carefully located within waveguides and CMOS solutions like self-alignment to the gate cannot be applied. In this work, we present different robust integration solutions for junction-based modulators. A simulation setup has been built in order to optimize of the process conditions. It consist in a Mathlab interface coupling process and device electro-optic simulators in order to run many iterations. Illustrations of modulator characteristic variations with process parameters are done using this simulation setup. Parameters under study are, for instance, X and Y direction lithography shifts, screening oxide and slab thicknesses. A robust process and design approach leading to a pn junction Mach Zehnder modulator insensitive to lithography misalignment is then proposed. Simulation results are compared with experimental datas. Indeed, various modulators have been fabricated with different process conditions and integration schemes. Extensive electro-optic characterization of these components will be presented.

Integrated nanopore sensing platform with sub-microsecond temporal resolution

PubMed Central

Rosenstein, Jacob K; Wanunu, Meni; Merchant, Christopher A; Drndic, Marija; Shepard, Kenneth L

2012-01-01

Nanopore sensors have attracted considerable interest for high-throughput sensing of individual nucleic acids and proteins without the need for chemical labels or complex optics. A prevailing problem in nanopore applications is that the transport kinetics of single biomolecules are often faster than the measurement time resolution. Methods to slow down biomolecular transport can be troublesome and are at odds with the natural goal of high-throughput sensing. Here we introduce a low-noise measurement platform that integrates a complementary metal-oxide semiconductor (CMOS) preamplifier with solid-state nanopores in thin silicon nitride membranes. With this platform we achieved a signal-to-noise ratio exceeding five at a bandwidth of 1 MHz, which to our knowledge is the highest bandwidth nanopore recording to date. We demonstrate transient signals as brief as 1 μs from short DNA molecules as well as current signatures during molecular passage events that shed light on submolecular DNA configurations in small nanopores. PMID:22426489

A Sol-gel Integrated Dual-readout Microarray Platform for Quantification and Identification of Prostate-specific Antigen.

PubMed

Lee, SangWook; Lee, Jong Hyun; Kwon, Hyuck Gi; Laurell, Thomas; Jeong, Ok Chan; Kim, Soyoun

2018-01-01

Here, we report a sol-gel integrated affinity microarray for on-chip matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) that enables capture and identification of prostate?specific antigen (PSA) in samples. An anti-PSA antibody (H117) was mixed with a sol?gel, and the mixture was spotted onto a porous silicon (pSi) surface without additional surface modifications. The antibody easily penetrates the sol-gel macropore fluidic network structure, making possible high affinities. To assess the capture affinity of the platform, we performed a direct assay using fluorescein isothiocyanate-labeled PSA. Pure PSA was subjected to on-chip MALDI-TOF-MS analysis, yielding three clear mass peptide peaks (m/z = 1272, 1407, and 1872). The sol-gel microarray platform enables dual readout of PSA both fluorometric and MALDI-TOF MS analysis in biological samples. Here we report a useful method for a means for discovery of biomarkers in complex body fluids.

Gait rehabilitation with a high tech platform based on virtual reality conveys improvements in walking ability of children suffering from acquired brain injury.

PubMed

Biffi, E; Beretta, E; Diella, E; Panzeri, D; Maghini, C; Turconi, A C; Strazzer, S; Reni, G

2015-01-01

The Gait Real-time Analysis Interactive Lab (GRAIL) is an instrumented multi-sensor platform based on immersive virtual reality for gait training and rehabilitation. Few studies have been included GRAIL to evaluate gait patterns in normal and disabled people and to improve gait in adults, while at our knowledge no evidence on its use for the rehabilitation of children is available. In this study, 4 children suffering from acquired brain injury (ABI) underwent a 5 session treatment with GRAIL, to improve walking and balance ability in engaging VR environments. The first and the last sessions were partially dedicated to gait evaluation. Results are promising: improvements were recorded at the ankle level, selectively at the affected side, and at the pelvic level, while small changes were measured at the hip and knee joints, which were already comparable to healthy subjects. All these changes also conveyed advances in the symmetry of the walking pattern. In the next future, a longer intervention will be proposed and more children will be enrolled to strongly prove the effectiveness of GRAIL in the rehabilitation of children with ABI.

Feasibility and Efficacy of a Urologic Profession Campaign on Cryptorchidism Using Internet and Social Media.

PubMed

Borgmann, Hendrik; Kliesch, Sabine; Roth, Stephan; Roth, Mael; Degener, Stephan

2017-01-01

We performed a professional campaign in Germany intending to establish the urologic profession as a competent and helpful point of contact for patients with cryptorchidism. The aim of this study was to assess the feasibility of this campaign and to quantify the efficacy of using Internet vs. social media. The strategic design of the campaign comprised a strategy meeting, creation of a landing page, and targeted advertisements on Google in the form of Adwords and on Facebook in the form of sidebar ads and sponsored posts. Outcome measurements were number of impressions, homepage sessions, and downloads of an information brochure. The campaign generated 2,511,923 impressions, 7,369 homepage sessions and 1,086 downloads of information brochures using a total investment budget of 7,500€. Use of Google Adwords was more efficient on outcome measurements than Facebook. A subanalysis of Facebook advertisements showed that sidebar ads and sponsored posts were equally efficient. New media are an effective platform for a profession campaign. Google Adwords is a more effective and cost-efficient platform than Facebook for a targeted campaign. © 2016 S. Karger AG, Basel.

Platform for Automated Real-Time High Performance Analytics on Medical Image Data.

PubMed

Allen, William J; Gabr, Refaat E; Tefera, Getaneh B; Pednekar, Amol S; Vaughn, Matthew W; Narayana, Ponnada A

2018-03-01

Biomedical data are quickly growing in volume and in variety, providing clinicians an opportunity for better clinical decision support. Here, we demonstrate a robust platform that uses software automation and high performance computing (HPC) resources to achieve real-time analytics of clinical data, specifically magnetic resonance imaging (MRI) data. We used the Agave application programming interface to facilitate communication, data transfer, and job control between an MRI scanner and an off-site HPC resource. In this use case, Agave executed the graphical pipeline tool GRAphical Pipeline Environment (GRAPE) to perform automated, real-time, quantitative analysis of MRI scans. Same-session image processing will open the door for adaptive scanning and real-time quality control, potentially accelerating the discovery of pathologies and minimizing patient callbacks. We envision this platform can be adapted to other medical instruments, HPC resources, and analytics tools.

[Effects of the neurogenesis stimulator Ro 25-6981 upon formation of spatial skill in adult rats depend on the term of its administration and the animals' ability to learn].

PubMed

Solov'eva, O A; Storozheva, Z I; Proshin, A T; Sherstnev, V V

2011-02-01

Effect of administration of selective N-methyl-D-aspartate (NMDA) receptor antagonist Ro 25-6981 on learning and memory in a dose which is known to stimulate neoneurogenesis was assessed in adult rats with different abilities to formation of spatial skills in different time periods after the antagonist injection. Wistar male rats were trained to find hidden platform in the Morris water maze for 5 consecutive days. Rats' learning ability for spatial skill formation was evaluated depending on platform speed achievements. In re-training sessions (cues and platform location changed), it was found that all rats received Ro 25-6981 13 days before the re-training demonstrated impaired spatial memory. At the same time the inhibitor injected 29 days before re-training selectively facilitated the formation of spatial skill in animals with initially low learning abilities.

Foundry Technologies Focused on Environmental and Ecological Applications

NASA Astrophysics Data System (ADS)

Roizin, Ya.; Lisiansky, M.; Pikhay, E.

Solutions allowing fabrication of remote control systems with integrated sensors (motes) were introduced as a part of CMOS foundry production platform and verified on silicon. The integrated features include sensors employing principles previously verified in the development of ultra-low power consuming non-volatile memories (C-Flash, MRAM) and components allowing low-power energy harvesting (low voltage rectifiers, high -voltage solar cells). The developed systems are discussed with emphasis on their environmental and security applications.

Development of a virtual multidisciplinary lung cancer tumor board in a community setting.

PubMed

Stevenson, Marvaretta M; Irwin, Tonia; Lowry, Terry; Ahmed, Maleka Z; Walden, Thomas L; Watson, Melanie; Sutton, Linda

2013-05-01

Creating an effective platform for multidisciplinary tumor conferences can be challenging in the rural community setting. The Duke Cancer Network created an Internet-based platform for a multidisciplinary conference to enhance the care of patients with lung cancer. This conference incorporates providers from different physical locations within a rural community and affiliated providers from a university-based cancer center 2 hours away. An electronic Web conferencing tool connects providers aurally and visually. Conferences were set up using a commercially available Web conferencing platform. The video platform provides a secure Web site coupled with a secure teleconference platform to ensure patient confidentiality. Multiple disciplines are invited to participate, including radiology, radiation oncology, thoracic surgery, pathology, and medical oncology. Participants only need telephone access and Internet connection to participate. Patient histories and physicals are presented, and the Web conferencing platform allows radiologic and histologic images to be reviewed. Treatment plans for patients are discussed, allowing providers to coordinate care among the different subspecialties. Patients who need referral to the affiliated university-based cancer center for specialized services are identified. Pertinent treatment guidelines and journal articles are reviewed. On average, there are 10 participants with one to two cases presented per session. The use of a Web conferencing platform allows subspecialty providers throughout the community and hours away to discuss lung cancer patient cases. This platform increases convenience for providers, eliminating travel to a central location. Coordination of care for patients requiring multidisciplinary care is facilitated, shortening evaluation time before definitive treatment plan.

Silicon on-chip bandpass filters for the multiplexing of high sensitivity photonic crystal microcavity biosensors

PubMed Central

Chakravarty, Swapnajit; Yang, Chun-Ju; Wang, Zheng; Tang, Naimei; Fan, Donglei; Chen, Ray T.

2015-01-01

A method for the dense integration of high sensitivity photonic crystal (PC) waveguide based biosensors is proposed and experimentally demonstrated on a silicon platform. By connecting an additional PC waveguide filter to a PC microcavity sensor in series, a transmission passband is created, containing the resonances of the PC microcavity for sensing purpose. With proper engineering of the passband, multiple high sensitivity PC microcavity sensors can be integrated into microarrays and be interrogated simultaneously between a single input and a single output port. The concept was demonstrated with a 2-channel L55 PC biosensor array containing PC waveguide filters. The experiment showed that the sensors on both channels can be monitored simultaneously from a single output spectrum. Less than 3 dB extra loss for the additional PC waveguide filter is observed. PMID:25829549

Planar Fully-Depleted-Silicon-On-Insulator technologies: Toward the 28 nm node and beyond

NASA Astrophysics Data System (ADS)

Doris, B.; DeSalvo, B.; Cheng, K.; Morin, P.; Vinet, M.

2016-03-01

This paper presents a comprehensive overview of the research done in the last decade on planar Fully-Depleted-Silicon-On-Insulator (FDSOI) technologies in the frame of the joint development program between IBM, ST Microelectronics and CEA-LETI. In particular, we review the technological developments ranging from substrate engineering to process modules that enable functionality and improve FDSOI performance over several generations. Various multi Vt integration schemes to maximize the benefits of the thin BOX FDSOI platform are discussed. Manufacturability as well as scalability concerns are highlighted and addressed. In addition, this work provides understanding of the performance/power trade-offs for FDSOI circuits and device variability. Finally, clear directions for future application-specific products are given, demonstrating that FDSOI is an attractive CMOS option for next generation high performance and low-power applications.

High-frequency and high-quality silicon carbide optomechanical microresonators

PubMed Central

Lu, Xiyuan; Lee, Jonathan Y.; Lin, Qiang

2015-01-01

Silicon carbide (SiC) exhibits excellent material properties attractive for broad applications. We demonstrate the first SiC optomechanical microresonators that integrate high mechanical frequency, high mechanical quality, and high optical quality into a single device. The radial-breathing mechanical mode has a mechanical frequency up to 1.69 GHz with a mechanical Q around 5500 in atmosphere, which corresponds to a fm · Qm product as high as 9.47 × 1012 Hz. The strong optomechanical coupling allows us to efficiently excite and probe the coherent mechanical oscillation by optical waves. The demonstrated devices, in combination with the superior thermal property, chemical inertness, and defect characteristics of SiC, show great potential for applications in metrology, sensing, and quantum photonics, particularly in harsh environments that are challenging for other device platforms. PMID:26585637

Three-dimensional patterning in polymer optical waveguides using focused ion beam milling

NASA Astrophysics Data System (ADS)

Kruse, Kevin; Burrell, Derek; Middlebrook, Christopher

2016-07-01

Waveguide (WG) photonic-bridge taper modules are designed for symmetric planar coupling between silicon WGs and single-mode fibers (SMFs) to minimize photonic chip and packaging footprint requirements with improving broadband functionality. Micromachined fabrication and evaluation of polymer WG tapers utilizing high-resolution focused ion beam (FIB) milling is performed and presented. Polymer etch rates utilizing the FIB and optimal methods for milling polymer tapers are identified for three-dimensional patterning. Polymer WG tapers with low sidewall roughness are manufactured utilizing FIB milling and optically tested for fabrication loss. FIB platforms utilize a focused beam of ions (Ga+) to etch submicron patterns into substrates. Fabricating low-loss polymer WG taper prototypes with the FIB before moving on to mass-production techniques provides theoretical understanding of the polymer taper and its feasibility for connectorization devices between silicon WGs and SMFs.

SERS detection of R6G based on a novel graphene oxide/silver nanoparticles/silicon pyramid arrays structure.

PubMed

Zhang, C; Jiang, S Z; Huo, Y Y; Liu, A H; Xu, S C; Liu, X Y; Sun, Z C; Xu, Y Y; Li, Z; Man, B Y

2015-09-21

We present a novel surface-enhanced Raman scattering (SERS) substrate based on graphene oxide/silver nanoparticles/silicon pyramid arrays structure (GO/Ag/PSi). The SERS behaviors are discussed and compared by the detection of R6G. Based on the contrast experiments with PSi, GO/PSi, Ag/PSi and GO/AgA/PSi as SERS substrate, the perfect bio-compatibility, good homogeneity and chemical stability were confirmed. We also calculated the electric field distributions using Finite-difference time-domain (FDTD) analysis to further understand the GO/Ag/PSi structure as a perfect SERS platform. These experimental and theoretical results imply that the GO/Ag/PSi with regular pyramids array is expected to be an effective substrate for label-free sensitive SERS detections in areas of medicine, food safety and biotechnology.

Low-Actuation Voltage MEMS Digital-to-Analog Converter with Parylene Spring Structures.

PubMed

Ma, Cheng-Wen; Lee, Fu-Wei; Liao, Hsin-Hung; Kuo, Wen-Cheng; Yang, Yao-Joe

2015-08-28

We propose an electrostatically-actuated microelectromechanical digital-to-analog converter (M-DAC) device with low actuation voltage. The spring structures of the silicon-based M-DAC device were monolithically fabricated using parylene-C. Because the Young's modulus of parylene-C is considerably lower than that of silicon, the electrostatic microactuators in the proposed device require much lower actuation voltages. The actuation voltage of the proposed M-DAC device is approximately 6 V, which is less than one half of the actuation voltages of a previously reported M-DAC equipped with electrostatic microactuators. The measured total displacement of the proposed three-bit M-DAC is nearly 504 nm, and the motion step is approximately 72 nm. Furthermore, we demonstrated that the M-DAC can be employed as a mirror platform with discrete displacement output for a noncontact surface profiling system.

Optomechanical and photothermal interactions in suspended photonic crystal membranes.

PubMed

Woolf, David; Hui, Pui-Chuen; Iwase, Eiji; Khan, Mughees; Rodriguez, Alejandro W; Deotare, Parag; Bulu, Irfan; Johnson, Steven G; Capasso, Federico; Loncar, Marko

2013-03-25

We present here an optomechanical system fabricated with novel stress management techniques that allow us to suspend an ultrathin defect-free silicon photonic-crystal membrane above a Silicon-on-Insulator (SOI) substrate with a gap that is tunable to below 200 nm. Our devices are able to generate strong attractive and repulsive optical forces over a large surface area with simple in- and out- coupling and feature the strongest repulsive optomechanical coupling in any geometry to date (gOM/2π ≈65 GHz/nm). The interplay between the optomechanical and photo-thermal-mechanical dynamics is explored, and the latter is used to achieve cooling and amplification of the mechanical mode, demonstrating that our platform is well-suited for potential applications in low-power mass, force, and refractive-index sensing as well as optomechanical accelerometry.

Small sensitivity to temperature variations of Si-photonic Mach-Zehnder interferometer using Si and SiN waveguides

NASA Astrophysics Data System (ADS)

Hiraki, Tatsurou; Fukuda, Hiroshi; Yamada, Koji; Yamamoto, Tsuyoshi

2015-03-01

We demonstrated a small sensitivity to temperature variations of delay-line Mach-Zehnder interferometer (DL MZI) on a Si photonics platform. The key technique is to balance a thermo-optic effect in the two arms by using waveguide made of different materials. With silicon and silicon nitride waveguides, the fabricated DL MZI with a free-spectrum range of ~40 GHz showed a wavelength shift of -2.8 pm/K with temperature variations, which is 24 times smaller than that of the conventional Si-waveguide DL MZI. We also demonstrated the decoding of the 40-Gbit/s differential phase-shift keying signals to on-off keying signals with various temperatures. The tolerable temperature variation for the acceptable power penalty was significantly improved due to the small wavelength shifts.

Neuromorphic audio-visual sensor fusion on a sound-localizing robot.

PubMed

Chan, Vincent Yue-Sek; Jin, Craig T; van Schaik, André

2012-01-01

This paper presents the first robotic system featuring audio-visual (AV) sensor fusion with neuromorphic sensors. We combine a pair of silicon cochleae and a silicon retina on a robotic platform to allow the robot to learn sound localization through self motion and visual feedback, using an adaptive ITD-based sound localization algorithm. After training, the robot can localize sound sources (white or pink noise) in a reverberant environment with an RMS error of 4-5° in azimuth. We also investigate the AV source binding problem and an experiment is conducted to test the effectiveness of matching an audio event with a corresponding visual event based on their onset time. Despite the simplicity of this method and a large number of false visual events in the background, a correct match can be made 75% of the time during the experiment.

A compact thermo-optical multimode-interference silicon-based 1 × 4 nano-photonic switch.

PubMed

Zhou, Haifeng; Song, Junfeng; Chee, Edward K S; Li, Chao; Zhang, Huijuan; Lo, Guoqiang

2013-09-09

An ultra-compact multimode-interference (MMI)-based 1 × 4 nano-photonic switch is demonstrated by employing silicon thermo-optical effect on SOI platform. The device performance is systematically characterized by comprehensively investigating the constituent building blocks, including 1 × 4 power splitter, 4 × 4 MMI coupler and groove-isolated thermo-optical heaters. An instructive model is established to statistically estimate the required power consumption and investigate the influence of the power imbalance of the 4 × 4 MMI coupler on the switching performance. At the designed wavelength of 1550 nm, the average insertion loss of different switching states is 1.7 dB, and the transmission imbalance is 1.05 dB. The worst extinction ratio and crosstalk of all the output ports reach 11.48 dB and -11.38 dB, respectively.

A Novel Treatment of Fear of Flying Using a Large Virtual Reality System.

PubMed

Czerniak, Efrat; Caspi, Asaf; Litvin, Michal; Amiaz, Revital; Bahat, Yotam; Baransi, Hani; Sharon, Hanania; Noy, Shlomo; Plotnik, Meir

2016-04-01

Fear of flying (FoF), a common phobia in the developed world, is usually treated with cognitive behavioral therapy, most efficiently when combined with exposure methods, e.g., virtual reality exposure therapy (VRET). We evaluated FoF treatment using VRET in a large motion-based VR system. The treated subjects were seated on a moving platform. The virtual scenery included the interior of an aircraft and a window view to the outside world accompanied by platform movements simulating, e.g., takeoff, landing, and air turbulence. Relevant auditory stimuli were also incorporated. Three male patients with FoF underwent a clinical interview followed by three VRETs in the presence and with the guidance of a therapist. Scores on the Flight Anxiety Situation (FAS) and Flight Anxiety Modality (FAM) questionnaires were obtained on the first and fourth visits. Anxiety levels were assessed using the subjective units of distress (SUDs) scale during the exposure. All three subjects expressed satisfaction regarding the procedure and did not skip or avoid any of its stages. Consistent improvement was seen in the SUDs throughout the VRET session and across sessions, while patients' scores on the FAS and FAM showed inconsistent trends. Two patients participated in actual flights in the months following the treatment, bringing 12 and 16 yr of avoidance to an end. This VR-based treatment includes critical elements for exposure of flying experience beyond visual and auditory stimuli. The current case reports suggest VRET sessions may have a meaningful impact on anxiety levels, yet additional research seems warranted.

Development of a Rover Simulation to Assess Operational Proficiency Following Long Duration Spaceflights

NASA Technical Reports Server (NTRS)

DeDios, Y. E.; Dean, S. L.; Rpsemtja (. K/); < acdpig (as/ J/ G/); Moore, S. T.; Wood, S. J.

2011-01-01

Following long-duration space transits, adaptive changes in sensorimotor and cognitive function may impair the crew s ability to safely control pressurized rovers designed to explore the new environment. We describe a rover simulation developed to quantify post-flight decrements in operational proficiency following International Space Station expeditions. The rover simulation consists of a serial presentation of discrete tasks to be completed as quickly and accurately as possible. Each task consists of 1) perspective taking using a map that defines a docking target, 2) navigation toward the target around a Martian outpost, and 3) docking a side hatch of the rover to a visually guided target. The simulator utilizes a Stewart-type motion base (CKAS, Australia), single seat cabin with triple scene projection covering approximately 150 horizontal by 40 vertical, and joystick controller. The software was implemented using Unity3 with next-gen PhysX engine to tightly synchronize simulation and motion platform commands. Separate C# applications allow investigators to customize session sequences with different lighting and gravitational conditions, and then execute tasks to be performed as well as record performance data. Preliminary tests resulted in low incidence of motion sickness (<15% unable to complete first session), with only negligible after effects and symptoms after familiarization sessions. Functionally relevant testing early post-flight will develop evidence regarding the limitations to early surface operations and what countermeasures are needed. This approach can be easily adapted to other vehicle designs to provide a platform to safely assess how sensorimotor and cognitive function impact manual control performance.

Public Engagement in Planetary Science through Europlanet Social Media

NASA Astrophysics Data System (ADS)

Heenatigala, T.

2017-09-01

From 'Save the Hubble' campaign to ESA's Rosetta mission, social media has played a major role in public engagement and continues to grow. However, with this growing number of social media platforms and the amount of content that goes public daily, the 'noise' level is high - making it difficult to reach a good, relevant audience. Hence, it's important to use different strategies with the content created, from launching a video to live session to issue a press release. Under the Horizon 2020, the Europlanet Media Centre[1] identifies the importance of using social media for outreach. Europlanet uses primary and secondary social media platforms strategically to engage with the followers and a new audience.

A nanowaveguide platform for collective atom-light interaction

NASA Astrophysics Data System (ADS)

Meng, Y.; Lee, J.; Dagenais, M.; Rolston, S. L.

2015-08-01

We propose a nanowaveguide platform for collective atom-light interaction through evanescent field coupling. We have developed a 1 cm-long silicon nitride nanowaveguide can use evanescent fields to trap and probe an ensemble of 87Rb atoms. The waveguide has a sub-micrometer square mode area and was designed with tapers for high fiber-to-waveguide coupling efficiencies at near-infrared wavelengths (750 nm to 1100 nm). Inverse tapers in the platform adiabatically transfer a weakly guided mode of fiber-coupled light into a strongly guided mode with an evanescent field to trap atoms and then back to a weakly guided mode at the other end of the waveguide. The coupling loss is -1 dB per facet (˜80% coupling efficiency) at 760 nm and 1064 nm, which is estimated by a propagation loss measurement with waveguides of different lengths. The proposed platform has good thermal conductance and can guide high optical powers for trapping atoms in ultra-high vacuum. As an intermediate step, we have observed thermal atom absorption of the evanescent component of a nanowaveguide and have demonstrated the U-wire mirror magneto-optical trap that can transfer atoms to the proximity of the surface.

All-soft, battery-free, and wireless chemical sensing platform based on liquid metal for liquid- and gas-phase VOC detection.

PubMed

Kim, Min-Gu; Alrowais, Hommood; Kim, Choongsoon; Yeon, Pyungwoo; Ghovanloo, Maysam; Brand, Oliver

2017-06-27

Lightweight, flexible, stretchable, and wireless sensing platforms have gained significant attention for personal healthcare and environmental monitoring applications. This paper introduces an all-soft (flexible and stretchable), battery-free, and wireless chemical microsystem using gallium-based liquid metal (eutectic gallium-indium alloy, EGaIn) and poly(dimethylsiloxane) (PDMS), fabricated using an advanced liquid metal thin-line patterning technique based on soft lithography. Considering its flexible, stretchable, and lightweight characteristics, the proposed sensing platform is well suited for wearable sensing applications either on the skin or on clothing. Using the microfluidic sensing platform, detection of liquid-phase and gas-phase volatile organic compounds (VOC) is demonstrated using the same design, which gives an opportunity to have the sensor operate under different working conditions and environments. In the case of liquid-phase chemical sensing, the wireless sensing performance and microfluidic capacitance tunability for different dielectric liquids are evaluated using analytical, numerical, and experimental approaches. In the case of gas-phase chemical sensing, PDMS is used both as a substrate and a sensing material. The gas sensing performance is evaluated and compared to a silicon-based, solid-state gas sensor with a PDMS sensing film.

UTBB FDSOI: Evolution and opportunities

NASA Astrophysics Data System (ADS)

Monfray, Stephane; Skotnicki, Thomas

2016-11-01

As today's 28 nm FDSOI (Fully Depleted Silicon On Insulator) technology is at the industrialization level, this paper aims to summarize the key advantages allowed by the thin BOX (Buried Oxide) of the FDSOI, through the technology evolution but also new opportunities, among logic applications and extending the possibilities offered by the platform. We will summarize how the advantages provided by the thin BOX have been first explored and developed, and how the back biasing techniques are the key to the outstanding performances provided by the FDSOI at low voltage. Then, as the FDSOI technology is also a solution to develop innovative platforms and applications, we will detail some opportunities. In particular, we will present monolithic 3D integration, ultra-low power devices for IoT (Internet of Things) and ultra-sensitive sensors.

Magnetic resonance imaging properties of multimodality anthropomorphic silicone rubber phantoms for validating surgical robots and image guided therapy systems

NASA Astrophysics Data System (ADS)

Cheung, Carling L.; Looi, Thomas; Drake, James; Kim, Peter C. W.

2012-02-01

The development of image guided robotic and mechatronic platforms for medical applications requires a phantom model for initial testing. Finding an appropriate phantom becomes challenging when the targeted patient population is pediatrics, particularly infants, neonates or fetuses. Our group is currently developing a pediatricsized surgical robot that operates under fused MRI and laparoscopic video guidance. To support this work, we describe a method for designing and manufacturing silicone rubber organ phantoms for the purpose of testing the robotics and the image fusion system. A surface model of the organ is obtained and converted into a mold that is then rapid-prototyped using a 3D printer. The mold is filled with a solution containing a particular ratio of silicone rubber to slacker additive to achieve a specific set of tactile and imaging characteristics in the phantom. The expected MRI relaxation times of different ratios of silicone rubber to slacker additive are experimentally quantified so that the imaging properties of the phantom can be matched to those of the organ that it represents. Samples of silicone rubber and slacker additive mixed in ratios ranging from 1:0 to 1:1.5 were prepared and scanned using inversion recovery and spin echo sequences with varying TI and TE, respectively, in order to fit curves to calculate the expected T1 and T2 relaxation times of each ratio. A set of infantsized abdominal organs was prepared, which were successfully sutured by the robot and imaged using different modalities.

On-Chip, Amplification-Free Quantification of Nucleic Acid for Point-of-Care Diagnosis

NASA Astrophysics Data System (ADS)

Yen, Tony Minghung

This dissertation demonstrates three physical device concepts to overcome limitations in point-of-care quantification of nucleic acids. Enabling sensitive, high throughput nucleic acid quantification on a chip, outside of hospital and centralized laboratory setting, is crucial for improving pathogen detection and cancer diagnosis and prognosis. Among existing platforms, microarray have the advantages of being amplification free, low instrument cost, and high throughput, but are generally less sensitive compared to sequencing and PCR assays. To bridge this performance gap, this dissertation presents theoretical and experimental progress to develop a platform nucleic acid quantification technology that is drastically more sensitive than current microarrays while compatible with microarray architecture. The first device concept explores on-chip nucleic acid enrichment by natural evaporation of nucleic acid solution droplet. Using a micro-patterned super-hydrophobic black silicon array device, evaporative enrichment is coupled with nano-liter droplet self-assembly workflow to produce a 50 aM concentration sensitivity, 6 orders of dynamic range, and rapid hybridization time at under 5 minutes. The second device concept focuses on improving target copy number sensitivity, instead of concentration sensitivity. A comprehensive microarray physical model taking into account of molecular transport, electrostatic intermolecular interactions, and reaction kinetics is considered to guide device optimization. Device pattern size and target copy number are optimized based on model prediction to achieve maximal hybridization efficiency. At a 100-mum pattern size, a quantum leap in detection limit of 570 copies is achieved using black silicon array device with self-assembled pico-liter droplet workflow. Despite its merits, evaporative enrichment on black silicon device suffers from coffee-ring effect at 100-mum pattern size, and thus not compatible with clinical patient samples. The third device concept utilizes an integrated optomechanical laser system and a Cytop microarray device to reverse coffee-ring effect during evaporative enrichment at 100-mum pattern size. This method, named "laser-induced differential evaporation" is expected to enable 570 copies detection limit for clinical samples in near future. While the work is ongoing as of the writing of this dissertation, a clear research plan is in place to implement this method on microarray platform toward clinical sample testing for disease applications and future commercialization.

Ultra-short silicon MMI duplexer

NASA Astrophysics Data System (ADS)

Yi, Huaxiang; Huang, Yawen; Wang, Xingjun; Zhou, Zhiping

2012-11-01

The fiber-to-the-home (FTTH) systems are growing fast these days, where two different wavelengths are used for upstream and downstream traffic, typically 1310nm and 1490nm. The duplexers are the key elements to separate these wavelengths into different path in central offices (CO) and optical network unit (ONU) in passive optical network (PON). Multimode interference (MMI) has some benefits to be a duplexer including large fabrication tolerance, low-temperature dependence, and low-polarization dependence, but its size is too large to integrate in conventional case. Based on the silicon photonics platform, ultra-short silicon MMI duplexer was demonstrated to separate the 1310nm and 1490nm lights. By studying the theory of self-image phenomena in MMI, the first order images are adopted in order to keep the device short. A cascaded MMI structure was investigated to implement the wavelength splitting, where both the light of 1310nm and 1490nm was input from the same port, and the 1490nm light was coupling cross the first MMI and output at the cross-port in the device while the 1310nm light was coupling through the first and second MMI and output at the bar-port in the device. The experiment was carried on with the SOI wafer of 340nm top silicon. The cascaded MMI was investigated to fold the length of the duplexer as short as 117μm with the extinct ratio over 10dB.

Software platform for simulation of a prototype proton CT scanner.

PubMed

Giacometti, Valentina; Bashkirov, Vladimir A; Piersimoni, Pierluigi; Guatelli, Susanna; Plautz, Tia E; Sadrozinski, Hartmut F-W; Johnson, Robert P; Zatserklyaniy, Andriy; Tessonnier, Thomas; Parodi, Katia; Rosenfeld, Anatoly B; Schulte, Reinhard W

2017-03-01

Proton computed tomography (pCT) is a promising imaging technique to substitute or at least complement x-ray CT for more accurate proton therapy treatment planning as it allows calculating directly proton relative stopping power from proton energy loss measurements. A proton CT scanner with a silicon-based particle tracking system and a five-stage scintillating energy detector has been completed. In parallel a modular software platform was developed to characterize the performance of the proposed pCT. The modular pCT software platform consists of (1) a Geant4-based simulation modeling the Loma Linda proton therapy beam line and the prototype proton CT scanner, (2) water equivalent path length (WEPL) calibration of the scintillating energy detector, and (3) image reconstruction algorithm for the reconstruction of the relative stopping power (RSP) of the scanned object. In this work, each component of the modular pCT software platform is described and validated with respect to experimental data and benchmarked against theoretical predictions. In particular, the RSP reconstruction was validated with both experimental scans, water column measurements, and theoretical calculations. The results show that the pCT software platform accurately reproduces the performance of the existing prototype pCT scanner with a RSP agreement between experimental and simulated values to better than 1.5%. The validated platform is a versatile tool for clinical proton CT performance and application studies in a virtual setting. The platform is flexible and can be modified to simulate not yet existing versions of pCT scanners and higher proton energies than those currently clinically available. © 2017 American Association of Physicists in Medicine.

The future of medical diagnostics: review paper

PubMed Central

2011-01-01

While histopathology of excised tissue remains the gold standard for diagnosis, several new, non-invasive diagnostic techniques are being developed. They rely on physical and biochemical changes that precede and mirror malignant change within tissue. The basic principle involves simple optical techniques of tissue interrogation. Their accuracy, expressed as sensitivity and specificity, are reported in a number of studies suggests that they have a potential for cost effective, real-time, in situ diagnosis. We review the Third Scientific Meeting of the Head and Neck Optical Diagnostics Society held in Congress Innsbruck, Innsbruck, Austria on the 11th May 2011. For the first time the HNODS Annual Scientific Meeting was held in association with the International Photodynamic Association (IPA) and the European Platform for Photodynamic Medicine (EPPM). The aim was to enhance the interdisciplinary aspects of optical diagnostics and other photodynamic applications. The meeting included 2 sections: oral communication sessions running in parallel to the IPA programme and poster presentation sessions combined with the IPA and EPPM posters sessions. PMID:21861912

Conversion of the Aerodynamic Preliminary Analysis System (APAS) to an IBM PC Compatible Format

NASA Technical Reports Server (NTRS)

Kruep, John M.

1995-01-01

The conversion of the Aerodynamic Preliminary Analysis System (APAS) software from a Silicon Graphics UNIX-based platform to a DOS-based IBM PC compatible is discussed. Relevant background information is given, followed by a discussion of the steps taken to accomplish the conversion and a discussion of the type of problems encountered during the conversion. A brief comparison of aerodynamic data obtained using APAS with data from another source is also made.

Development of L-lactate dehydrogenase biosensor based on porous silicon resonant microcavities as fluorescence enhancers.

PubMed

Jenie, S N Aisyiyah; Prieto-Simon, Beatriz; Voelcker, Nicolas H

2015-12-15

The up-regulation of L-lactate dehydrogenase (LDH), an intracellular enzyme present in most of all body tissues, is indicative of several pathological conditions and cellular death. Herein, we demonstrate LDH detection using porous silicon (pSi) microcavities as a luminescence-enhancing optical biosensing platform. Non-fluorescent resazurin was covalently attached onto the pSi surface via thermal hydrocarbonisation, thermal hydrosylilation and acylation. Each surface modification step was confirmed by means of FTIR and the optical shifts of the resonance wavelength of the microcavity. Thermal hydrocarbonisation also afforded excellent surface stability, ensuring that the resazurin was not reduced on the pSi surface. Using a pSi microcavity biosensor, the fluorescence signal upon detection of LDH was amplified by 10 and 5-fold compared to that of a single layer and a detuned microcavity, respectively, giving a limit of detection of 0.08 U/ml. The biosensor showed a linear response between 0.16 and 6.5 U/ml, covering the concentration range of LDH in normal as well as damaged tissues. The biosensor was selective for LDH and did not produce a signal upon incubation with another NAD-dependant enzyme L-glutamic dehydrogenase. The use of the pSi microcavity as a sensing platform reduced reagent usage by 30% and analysis time threefold compared to the standard LDH assay in solution. Copyright © 2015 Elsevier B.V. All rights reserved.

Suspended mid-infrared fiber-to-chip grating couplers for SiGe waveguides

NASA Astrophysics Data System (ADS)

Favreau, Julien; Durantin, Cédric; Fédéli, Jean-Marc; Boutami, Salim; Duan, Guang-Hua

2016-03-01

Silicon photonics has taken great importance owing to the applications in optical communications, ranging from short reach to long haul. Originally dedicated to telecom wavelengths, silicon photonics is heading toward circuits handling with a broader spectrum, especially in the short and mid-infrared (MIR) range. This trend is due to potential applications in chemical sensing, spectroscopy and defense in the 2-10 μm range. We previously reported the development of a MIR photonic platform based on buried SiGe/Si waveguide with propagation losses between 1 and 2 dB/cm. However the low index contrast of the platform makes the design of efficient grating couplers very challenging. In order to achieve a high fiber-to-chip efficiency, we propose a novel grating coupler structure, in which the grating is locally suspended in air. The grating has been designed with a FDTD software. To achieve high efficiency, suspended structure thicknesses have been jointly optimized with the grating parameters, namely the fill factor, the period and the grating etch depth. Using the Efficient Global Optimization (EGO) method we obtained a configuration where the fiber-to-waveguide efficiency is above 57 %. Moreover the optical transition between the suspended and the buried SiGe waveguide has been carefully designed by using an Eigenmode Expansion software. Transition efficiency as high as 86 % is achieved.

Integrated optical sensors for 2D spatial chemical mapping (Conference Presentation)

NASA Astrophysics Data System (ADS)

Flores, Raquel; Janeiro, Ricardo; Viegas, Jaime

2017-02-01

Sensors based on optical waveguides for chemical sensing have attracted increasing interest over the last two decades, fueled by potential applications in commercial lab-on-a-chip devices for medical and food safety industries. Even though the early studies were oriented for single-point detection, progress in device size reduction and device yield afforded by photonics foundries have opened the opportunity for distributed dynamic chemical sensing at the microscale. This will allow researchers to follow the dynamics of chemical species in field of microbiology, and microchemistry, with a complementary method to current technologies based on microfluorescence and hyperspectral imaging. The study of the chemical dynamics at the surface of photoelectrodes in water splitting cells are a good candidate to benefit from such optochemical sensing devices that includes a photonic integrated circuit (PIC) with multiple sensors for real-time detection and spatial mapping of chemical species. In this project, we present experimental results on a prototype integrated optical system for chemical mapping based on the interaction of cascaded resonant optical devices, spatially covered with chemically sensitive polymers and plasmon-enhanced nanostructured metal/metal-oxide claddings offering chemical selectivity in a pixelated surface. In order to achieve a compact footprint, the prototype is based in a silicon photonics platform. A discussion on the relative merits of a photonic platform based on large bandgap metal oxides and nitrides which have higher chemical resistance than silicon is also presented.

High Level of Integration in Integrated Disease Management Leads to Higher Usage in the e-Vita Study: Self-Management of Chronic Obstructive Pulmonary Disease With Web-Based Platforms in a Parallel Cohort Design.

PubMed

Talboom-Kamp, Esther Pwa; Verdijk, Noortje A; Kasteleyn, Marise J; Harmans, Lara M; Talboom, Irvin Jsh; Numans, Mattijs E; Chavannes, Niels H

2017-05-31

Worldwide, nearly 3 million people die of chronic obstructive pulmonary disease (COPD) every year. Integrated disease management (IDM) improves disease-specific quality of life and exercise capacity for people with COPD, but can also reduce hospital admissions and hospital days. Self-management of COPD through eHealth interventions has shown to be an effective method to improve the quality and efficiency of IDM in several settings, but it remains unknown which factors influence usage of eHealth and change in behavior of patients. Our study, e-Vita COPD, compares different levels of integration of Web-based self-management platforms in IDM in three primary care settings. The main aim of this study is to analyze the factors that successfully promote the use of a self-management platform for COPD patients. The e-Vita COPD study compares three different approaches to incorporating eHealth via Web-based self-management platforms into IDM of COPD using a parallel cohort design. Three groups integrated the platforms to different levels. In groups 1 (high integration) and 2 (medium integration), randomization was performed to two levels of personal assistance for patients (high and low assistance); in group 3 there was no integration into disease management (none integration). Every visit to the e-Vita and Zorgdraad COPD Web platforms was tracked objectively by collecting log data (sessions and services). At the first log-in, patients completed a baseline questionnaire. Baseline characteristics were automatically extracted from the log files including age, gender, education level, scores on the Clinical COPD Questionnaire (CCQ), dyspnea scale (MRC), and quality of life questionnaire (EQ5D). To predict the use of the platforms, multiple linear regression analyses for the different independent variables were performed: integration in IDM (high, medium, none), personal assistance for the participants (high vs low), educational level, and self-efficacy level (General Self-Efficacy Scale [GSES]). All analyses were adjusted for age and gender. Of the 702 invited COPD patients, 215 (30.6%) registered to a platform. Of the 82 patients in group 1 (high integration IDM), 36 were in group 1A (personal assistance) and 46 in group 1B (low assistance). Of the 96 patients in group 2 (medium integration IDM), 44 were in group 2A (telephone assistance) and 52 in group 2B (low assistance). A total of 37 patients participated in group 3 (no integration IDM). In all, 107 users (49.8%) visited the platform at least once in the 15-month period. The mean number of sessions differed between the three groups (group 1: mean 10.5, SD 1.3; group 2: mean 8.8, SD 1.4; group 3: mean 3.7, SD 1.8; P=.01). The mean number of sessions differed between the high-assistance and low-assistance groups in groups 1 and 2 (high: mean 11.8, SD 1.3; low: mean 6.7, SD 1.4; F1,80=6.55, P=.01). High-assistance participants used more services (mean 45.4, SD 6.2) than low-assistance participants (mean 21.2, SD 6.8; F1,80=6.82, P=.01). No association was found between educational level and usage and between GSES and usage. Use of a self-management platform is higher when participants receive adequate personal assistance about how to use the platform. Blended care, where digital health and usual care are integrated, will likely lead to increased use of the online program. Future research should provide additional insights into the preferences of different patient groups. Nederlands Trial Register NTR4098; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4098 (Archived by WebCite at http://www.webcitation.org/6qO1hqiJ1). ©Esther PWA Talboom-Kamp, Noortje A Verdijk, Marise J Kasteleyn, Lara M Harmans, Irvin JSH Talboom, Mattijs E Numans, Niels H Chavannes. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 31.05.2017.

Comparison of Amicus and COBE Spectra for allogenic peripheral blood stem cell harvest: Study from tertiary care centre in India.

PubMed

Setia, Rasika Dhawan; Arora, Satyam; Handoo, Anil; Dadu, Tina; Choudhary, Dharma; Sharma, Sajeev Kumar; Kharya, Gaurav; Khandelwal, Vipin; Sachdeva, Prerna; Doval, Divya; Bakliwal, Anamika; Kapoor, Meenu; Bajaj, Shalu; Bachchas, Virendra; Singh, Praveen

2017-06-01

Most common source of stem cell graft for both autologous and allogenic haematopoietic transplants are peripheral blood haematopoietic progenitor stem cells. Adequate collection of the CD34+ cells and safety of the allogenic donor during the leukapheresis are of prime importance to an apheresis physician. Our retrospective analysis is a comparison between of two platforms namely, COBE Spectra and Amicus, for CD34+ mononuclear cell collection. The study included the data of GSCF (Granulocyte-Colony-Stimulating Factor) mobilized allogenic PBSC collections at our centre from January 2015 to June 2016. The apheresis platforms used were COBE Spectra and Amicus. Blood cell counts were done using LH750 Beckman Coulter (Florida, Miami, USA). CD45+ & CD34+ cell counts were done using BD FACS Canto-II Flow-Cytometer by ISHAGE guidelines. A total of 170 PBSC (100 COBE Spectra & 70 Amicus) harvests were done on 143 donors, of which 116 completed the collection in a single session and 27 required a second session. Demographic details and pre harvest peripheral blood counts for both the groups did not show any statistical differences. Amicus processed higher blood volume with higher ACD exposure and procedure time compared to COBE Spectra. Higher platelets loss was with COBE Spectra harvests with higher product volumes collection. Collection efficiency (CE2), collection ratio, CD34+ cells dose was similar on both the platforms. RBC contamination, absolute lymphocyte and monocytes counts were significantly higher with Amicus harvest product compared with COBE Spectra. A total of 14 (8.2%; citrate toxicity) adverse reactions were reported out of 170 allogenic PBSC collections. Our study suggests that both Amicus and COBE Spectra platforms offer comparable results for allogenic PBSC collections. Amicus offers a concentrated PBSC product with lesser volume and platelets loss but higher RBC contamination. Copyright © 2017 Elsevier Ltd. All rights reserved.

A fully integrated oven controlled microelectromechanical oscillator -- Part I. Design and fabrication

DOE PAGES

Wojciechowski, Kenneth E.; Baker, Michael S.; Clews, Peggy J.; ...

2015-06-24

Our paper reports the design and fabrication of a fully integrated oven controlled microelectromechanical oscillator (OCMO). This paper begins by describing the limits on oscillator frequency stability imposed by the thermal drift and electronic properties (Q, resistance) of both the resonant tank circuit and feedback electronics required to form an electronic oscillator. An OCMO is presented that takes advantage of high thermal isolation and monolithic integration of both micromechanical resonators and electronic circuitry to thermally stabilize or ovenize all the components that comprise an oscillator. This was achieved by developing a processing technique where both silicon-on-insulator complementary metal-oxide-semiconductor (CMOS) circuitrymore » and piezoelectric aluminum nitride, AlN, micromechanical resonators are placed on a suspended platform within a standard CMOS integrated circuit. Operation at microscale sizes achieves high thermal resistances (~10 °C/mW), and hence thermal stabilization of the oscillators at very low-power levels when compared with the state-of-the-art ovenized crystal oscillators, OCXO. This constant resistance feedback circuit is presented that incorporates on platform resistive heaters and temperature sensors to both measure and stabilize the platform temperature. Moreover, the limits on temperature stability of the OCMO platform and oscillator frequency imposed by the gain of the constant resistance feedback loop, placement of the heater and temperature sensing resistors, as well as platform radiative and convective heat losses are investigated.« less

Development of a Virtual Multidisciplinary Lung Cancer Tumor Board in a Community Setting

PubMed Central

Stevenson, Marvaretta M.; Irwin, Tonia; Lowry, Terry; Ahmed, Maleka Z.; Walden, Thomas L.; Watson, Melanie; Sutton, Linda

2013-01-01

Purpose: Creating an effective platform for multidisciplinary tumor conferences can be challenging in the rural community setting. The Duke Cancer Network created an Internet-based platform for a multidisciplinary conference to enhance the care of patients with lung cancer. This conference incorporates providers from different physical locations within a rural community and affiliated providers from a university-based cancer center 2 hours away. An electronic Web conferencing tool connects providers aurally and visually. Methods: Conferences were set up using a commercially available Web conferencing platform. The video platform provides a secure Web site coupled with a secure teleconference platform to ensure patient confidentiality. Multiple disciplines are invited to participate, including radiology, radiation oncology, thoracic surgery, pathology, and medical oncology. Participants only need telephone access and Internet connection to participate. Results: Patient histories and physicals are presented, and the Web conferencing platform allows radiologic and histologic images to be reviewed. Treatment plans for patients are discussed, allowing providers to coordinate care among the different subspecialties. Patients who need referral to the affiliated university-based cancer center for specialized services are identified. Pertinent treatment guidelines and journal articles are reviewed. On average, there are 10 participants with one to two cases presented per session. Conclusion: The use of a Web conferencing platform allows subspecialty providers throughout the community and hours away to discuss lung cancer patient cases. This platform increases convenience for providers, eliminating travel to a central location. Coordination of care for patients requiring multidisciplinary care is facilitated, shortening evaluation time before definitive treatment plan. PMID:23942505

Characterization of Silicon Photomultiplier Detectors using Cosmic Radiation

NASA Astrophysics Data System (ADS)

Zavala, Favian; Castro, Juan; Niduaza, Rexavalmar; Wedel, Zachary; Fan, Sewan; Ritt, Stefan; Fatuzzo, Laura

2014-03-01

The silicon photomultiplier light detector has gained a lot of attention lately in fields such as particle physics, astrophysics, and medical physics. Its popularity stems from its lower cost, compact size, insensitivity to magnetic fields, and its excellent ability to distinguish a quantized number of photons. They are normally operated at room temperature and biased above their breakdown voltages. As such, they may also exhibit properties that may hinder their optimal operation which include a thermally induced high dark count rate, after pulse effects, and cross talk from photons in nearby pixels. At this poster session, we describe our data analysis and our endeavor to characterize the multipixel photon counter (MPPC) detectors from Hamamatsu under different bias voltages and temperature conditions. Particularly, we describe our setup which uses cosmic rays to induce scintillation light delivered to the detector by wavelength shifting optical fibers and the use of a fast 1 GHz waveform sampler, the domino ring sampler (DRS4) digitizer board. Department of Education grant number P031S90007.

Effect of Ion Flux (Dose Rate) in Source-Drain Extension Ion Implantation for 10-nm Node FinFET and Beyond on 300/450mm Platforms

NASA Astrophysics Data System (ADS)

Shen, Ming-Yi

The improvement of wafer equipment productivity has been a continuous effort of the semiconductor industry. Higher productivity implies lower product price, which economically drives more demand from the market. This is desired by the semiconductor manufacturing industry. By raising the ion beam current of the ion implanter for 300/450mm platforms, it is possible to increase the throughput of the ion implanter. The resulting dose rate can be comparable to the performance of conventional ion implanters or higher, depending on beam current and beam size. Thus, effects caused by higher dose rate must be investigated further. One of the major applications of ion implantation (I/I) is source-drain extension (SDE) I/I for the silicon FinFET device. This study investigated the dose rate effects on the material properties and device performance of the 10-nm node silicon FinFET. In order to gain better understanding of the dose rate effects, the dose rate study is based on Synopsys Technology CAD (TCAD) process and device simulations that are calibrated and validated using available structural silicon fin samples. We have successfully shown that the kinetic monte carlo (KMC) I/I simulation can precisely model both the silicon amorphization and the arsenic distribution in the fin by comparing the KMC simulation results with TEM images. The results of the KMC I/I simulation show that at high dose rate more activated arsenic dopants were in the source-drain extension (SDE) region. This finding matches with the increased silicon amorphization caused by the high dose-rate I/I, given that the arsenic atoms could be more easily activated by the solid phase epitaxial regrowth process. This increased silicon amorphization led to not only higher arsenic activation near the spacer edge, but also less arsenic atoms straggling into the channel. Hence, it is possible to improve the throughput of the ion implanter when the dopants are implanted at high dose rate if the same doping level with a lower wafer dose can be achieved. In addition, the leakage current might also be reduced due to less undesired dopants in the channel. However, the twin defects from the problematic Si{111} recrystallization is well-known to cause excessive leakage current to the FinFET. This drawback can offset the benefits of the high dose rate I/I mentioned above. This work produced the first attempt at simulating the electrical impact of twin defects on advanced-node (10 nm) FinFET device performance. It was found that the high dose-rate I/I causes more twin defects in the silicon fin, and the physical locations of these defects were close to the channel. The defects undesirably induced trap-assisted band-to-band tunneling near the drain, which increased the leakage current. This issue could be mitigated by using asymmetrical gate overlap/underlap design or thicker spacer for SDE I/I so that the twin defects are not located in the depletion region near the drain.

Quantum information density scaling and qubit operation time constraints of CMOS silicon-based quantum computer architectures

NASA Astrophysics Data System (ADS)

Rotta, Davide; Sebastiano, Fabio; Charbon, Edoardo; Prati, Enrico

2017-06-01

Even the quantum simulation of an apparently simple molecule such as Fe2S2 requires a considerable number of qubits of the order of 106, while more complex molecules such as alanine (C3H7NO2) require about a hundred times more. In order to assess such a multimillion scale of identical qubits and control lines, the silicon platform seems to be one of the most indicated routes as it naturally provides, together with qubit functionalities, the capability of nanometric, serial, and industrial-quality fabrication. The scaling trend of microelectronic devices predicting that computing power would double every 2 years, known as Moore's law, according to the new slope set after the 32-nm node of 2009, suggests that the technology roadmap will achieve the 3-nm manufacturability limit proposed by Kelly around 2020. Today, circuital quantum information processing architectures are predicted to take advantage from the scalability ensured by silicon technology. However, the maximum amount of quantum information per unit surface that can be stored in silicon-based qubits and the consequent space constraints on qubit operations have never been addressed so far. This represents one of the key parameters toward the implementation of quantum error correction for fault-tolerant quantum information processing and its dependence on the features of the technology node. The maximum quantum information per unit surface virtually storable and controllable in the compact exchange-only silicon double quantum dot qubit architecture is expressed as a function of the complementary metal-oxide-semiconductor technology node, so the size scale optimizing both physical qubit operation time and quantum error correction requirements is assessed by reviewing the physical and technological constraints. According to the requirements imposed by the quantum error correction method and the constraints given by the typical strength of the exchange coupling, we determine the workable operation frequency range of a silicon complementary metal-oxide-semiconductor quantum processor to be within 1 and 100 GHz. Such constraint limits the feasibility of fault-tolerant quantum information processing with complementary metal-oxide-semiconductor technology only to the most advanced nodes. The compatibility with classical complementary metal-oxide-semiconductor control circuitry is discussed, focusing on the cryogenic complementary metal-oxide-semiconductor operation required to bring the classical controller as close as possible to the quantum processor and to enable interfacing thousands of qubits on the same chip via time-division, frequency-division, and space-division multiplexing. The operation time range prospected for cryogenic control electronics is found to be compatible with the operation time expected for qubits. By combining the forecast of the development of scaled technology nodes with operation time and classical circuitry constraints, we derive a maximum quantum information density for logical qubits of 2.8 and 4 Mqb/cm2 for the 10 and 7-nm technology nodes, respectively, for the Steane code. The density is one and two orders of magnitude less for surface codes and for concatenated codes, respectively. Such values provide a benchmark for the development of fault-tolerant quantum algorithms by circuital quantum information based on silicon platforms and a guideline for other technologies in general.

Growing InGaAs quasi-quantum wires inside semi-rhombic shaped planar InP nanowires on exact (001) silicon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Yu; Li, Qiang; Lau, Kei May, E-mail: eekmlau@ust.hk

We report InGaAs quasi-quantum wires embedded in planar InP nanowires grown on (001) silicon emitting in the 1550 nm communication band. An array of highly ordered InP nanowire with semi-rhombic cross-section was obtained in pre-defined silicon V-grooves through selective-area hetero-epitaxy. The 8% lattice mismatch between InP and Si was accommodated by an ultra-thin stacking disordered InP/GaAs nucleation layer. X-ray diffraction and transmission electron microscope characterizations suggest excellent crystalline quality of the nanowires. By exploiting the morphological evolution of the InP and a self-limiting growth process in the V-grooves, we grew embedded InGaAs quantum-wells and quasi-quantum-wires with tunable shape and position. Roommore » temperature analysis reveals substantially improved photoluminescence in the quasi-quantum wires as compared to the quantum-well reference, due to the reduced intrusion defects and enhanced quantum confinement. These results show great promise for integration of III-V based long wavelength nanowire lasers on the well-established (001) Si platform.« less

Optical fiber Bragg grating-instrumented silicone liner for interface pressure measurement within prosthetic sockets of lower-limb amputees.

PubMed

Al-Fakih, Ebrahim; Arifin, Nooranida; Pirouzi, Gholamhossein; Mahamd Adikan, Faisal Rafiq; Shasmin, Hanie Nadia; Abu Osman, Noor Azuan

2017-08-01

This paper presents a fiber Bragg grating (FBG)-instrumented prosthetic silicone liner that provides cushioning for the residual limb and can successfully measure interface pressures inside prosthetic sockets of lower-limb amputees in a simple and practical means of sensing. The liner is made of two silicone layers between which 12 FBG sensors were embedded at locations of clinical interest. The sensors were then calibrated using a custom calibration platform that mimics a real-life situation. Afterward, a custom gait simulating machine was built to test the liner performance during an amputee's simulated gait. To validate the findings, the results were compared to those obtained by the commonly used F-socket mats. As the statistical findings reveal, both pressure mapping methods measured the interface pressure in a consistent way, with no significant difference (P-values ≥0.05). This pressure mapping technique in the form of a prosthetic liner will allow prosthetics professionals to quickly and accurately create an overall picture of the interface pressure distribution inside sockets in research and clinical settings, thereby improving the socket fit and amputee's satisfaction. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Selective on site separation and detection of molecules in diluted solutions with super-hydrophobic clusters of plasmonic nanoparticles.

PubMed

Gentile, Francesco; Coluccio, Maria Laura; Zaccaria, Remo Proietti; Francardi, Marco; Cojoc, Gheorghe; Perozziello, Gerardo; Raimondo, Raffaella; Candeloro, Patrizio; Di Fabrizio, Enzo

2014-07-21

Super-hydrophobic surfaces are bio-inspired interfaces with a superficial texture that, in its most common evolution, is formed by a periodic lattice of silicon micro-pillars. Similar surfaces reveal superior properties compared to conventional flat surfaces, including very low friction coefficients. In this work, we modified meso-porous silicon micro-pillars to incorporate networks of metal nano-particles into the porous matrix. In doing so, we obtained a multifunctional-hierarchical system in which (i) at a larger micrometric scale, the super-hydrophobic pillars bring the molecules dissolved in an ultralow-concentration droplet to the active sites of the device, (ii) at an intermediate meso-scale, the meso-porous silicon film adsorbs the low molecular weight content of the solution and, (iii) at a smaller nanometric scale, the aggregates of silver nano-particles would measure the target molecules with unprecedented sensitivity. In the results, we demonstrated how this scheme can be utilized to isolate and detect small molecules in a diluted solution in very low abundance ranges. The presented platform, coupled to Raman or other spectroscopy techniques, is a realistic candidate for the protein expression profiling of biological fluids.

An integrated optic ethanol vapor sensor based on a silicon-on-insulator microring resonator coated with a porous ZnO film.

PubMed

Yebo, Nebiyu A; Lommens, Petra; Hens, Zeger; Baets, Roel

2010-05-24

Optical structures fabricated on silicon-on-insulator technology provide a convenient platform for the implementation of highly compact, versatile and low cost devices. In this work, we demonstrate the promise of this technology for integrated low power and low cost optical gas sensing. A room temperature ethanol vapor sensor is demonstrated using a ZnO nanoparticle film as a coating on an SOI micro-ring resonator of 5 microm in radius. The local coating on the ring resonators is prepared from colloidal suspensions of ZnO nanoparticles of around 3 nm diameter. The porous nature of the coating provides a large surface area for gas adsorption. The ZnO refractive index change upon vapor adsorption shifts the microring resonance through evanescent field interaction. Ethanol vapor concentrations down to 100 ppm are detected with this sensing configuration and a detection limit below 25 ppm is estimated.

Polymer waveguide grating sensor integrated with a thin-film photodetector

PubMed Central

Song, Fuchuan; Xiao, Jing; Xie, Antonio Jou; Seo, Sang-Woo

2014-01-01

This paper presents a planar waveguide grating sensor integrated with a photodetector (PD) for on-chip optical sensing systems which are suitable for diagnostics in the field and in-situ measurements. III–V semiconductor-based thin-film PD is integrated with a polymer based waveguide grating device on a silicon platform. The fabricated optical sensor successfully discriminates optical spectral characteristics of the polymer waveguide grating from the on-chip PD. In addition, its potential use as a refractive index sensor is demonstrated. Based on a planar waveguide structure, the demonstrated sensor chip may incorporate multiple grating waveguide sensing regions with their own optical detection PDs. In addition, the demonstrated processing is based on a post-integration process which is compatible with silicon complementary metal-oxide semiconductor (CMOS) electronics. Potentially, this leads a compact, chip-scale optical sensing system which can monitor multiple physical parameters simultaneously without need for external signal processing. PMID:24466407

CAOS-CMOS camera.

PubMed

Riza, Nabeel A; La Torre, Juan Pablo; Amin, M Junaid

2016-06-13

Proposed and experimentally demonstrated is the CAOS-CMOS camera design that combines the coded access optical sensor (CAOS) imager platform with the CMOS multi-pixel optical sensor. The unique CAOS-CMOS camera engages the classic CMOS sensor light staring mode with the time-frequency-space agile pixel CAOS imager mode within one programmable optical unit to realize a high dynamic range imager for extreme light contrast conditions. The experimentally demonstrated CAOS-CMOS camera is built using a digital micromirror device, a silicon point-photo-detector with a variable gain amplifier, and a silicon CMOS sensor with a maximum rated 51.3 dB dynamic range. White light imaging of three different brightness simultaneously viewed targets, that is not possible by the CMOS sensor, is achieved by the CAOS-CMOS camera demonstrating an 82.06 dB dynamic range. Applications for the camera include industrial machine vision, welding, laser analysis, automotive, night vision, surveillance and multispectral military systems.

Toward athermal silicon-on-insulator (de)multiplexers in the O-band.

PubMed

Hassan, Karim; Sciancalepore, Corrado; Harduin, Julie; Ferrotti, Thomas; Menezo, Sylvie; Ben Bakir, Badhise

2015-06-01

We report on the design, fabrication, and characterization of a 1×4 silicon-on-insulator (SOI) demultiplexer exhibiting a significant reduction of its thermo-optical sensitivity in the O-band. The optical filtering is achieved by cascading several Mach-Zehnder interferometers (MZIs) fabricated on a 300-nm-thick SOI platform. Owing to an asymmetric design of the confinement for each MZIs, we found an athermal criterium that satisfies the spectral requirements. The thermal sensitivity of the structure is analyzed by a semi-analytical model in order to create an athermal multiplexer. Fiber-to-fiber thermo-optical testing reveals a thermal sensitivity of around 17  pm/°C reduced by 75% compared to the standard devices with promising performances for both the crosstalk (15 dB), the insertion losses (4 dB), and absolute lambda registration (<0.25  nm).

Design and fabrication of MEMS devices using the integration of MUMPs, trench-refilled molding, DRIE and bulk silicon etching processes

NASA Astrophysics Data System (ADS)

Wu, Mingching; Fang, Weileun

2005-03-01

This work integrates multi-depth DRIE etching, trench-refilled molding, two poly-Si layers MUMPs and bulk releasing to improve the variety and performance of MEMS devices. In summary, the present fabrication process, named MOSBE II, has three merits. First, this process can monolithically fabricate and integrate poly-Si thin-film structures with different thicknesses and stiffnesses, such as the flexible spring and the stiff mirror plate. Second, multi-depth structures, such as vertical comb electrodes, are available from the DRIE processes. Third, a cavity under the micromachined device is provided by the bulk silicon etching process, so that a large out-of-plane motion is allowed. In application, an optical scanner driven by the self-aligned vertical comb actuator was demonstrated. The poly-Si micromachined components fabricated by MOSBE II can further integrate with the MUMPs devices to establish a more powerful MOEMS platform.

3D printing of robotic soft actuators with programmable bioinspired architectures.

PubMed

Schaffner, Manuel; Faber, Jakob A; Pianegonda, Lucas; Rühs, Patrick A; Coulter, Fergal; Studart, André R

2018-02-28

Soft actuation allows robots to interact safely with humans, other machines, and their surroundings. Full exploitation of the potential of soft actuators has, however, been hindered by the lack of simple manufacturing routes to generate multimaterial parts with intricate shapes and architectures. Here, we report a 3D printing platform for the seamless digital fabrication of pneumatic silicone actuators exhibiting programmable bioinspired architectures and motions. The actuators comprise an elastomeric body whose surface is decorated with reinforcing stripes at a well-defined lead angle. Similar to the fibrous architectures found in muscular hydrostats, the lead angle can be altered to achieve elongation, contraction, or twisting motions. Using a quantitative model based on lamination theory, we establish design principles for the digital fabrication of silicone-based soft actuators whose functional response is programmed within the material's properties and architecture. Exploring such programmability enables 3D printing of a broad range of soft morphing structures.

Suspended light-emitting diode featuring a bottom dielectric distributed Bragg reflector

NASA Astrophysics Data System (ADS)

Cai, Wei; Wang, Wei; Zhu, Bingcheng; Gao, Xumin; Zhu, Guixia; Yuan, Jialei; Wang, Yongjin

2018-01-01

Here, we propose, fabricate and characterize the light manipulation of a suspended-membrane InGaN/GaN multiple-quantum-well light-emitting diode (MQW-LED) with a dielectric distributed Bragg reflector (DBR) positioned at the bottom, implemented on a GaN-on-silicon platform. Silicon removal is conducted to obtain the suspended MQW-LED architecture, and back wafer thinning of the epitaxial film is performed to improve the device performance. A 6-pair SiO2/Ta2O5 DBR is deposited on the backside to manipulate the emitted light. The experimental results demonstrate that the bottom dielectric DBR exhibits high reflectivity and distinctly changes the light emission, which are consistent with the performed simulation results. This work represents a significant step towards the realization of inexpensive, electrically driven and simply fabricated GaN VCSELs for potential use in number of applications.

3D calcite heterostructures for dynamic and deformable mineralized matrices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yi, Jaeseok; Wang, Yucai; Jiang, Yuanwen

Scales are rooted in soft tissues, and are regenerated by specialized cells. The realization of dynamic synthetic analogues with inorganic materials has been a significant challenge, because the abiological regeneration sites that could yield deterministic growth behavior are hard to form. Here we overcome this fundamental hurdle by constructing a mutable and deformable array of three-dimensional calcite heterostructures that are partially locked in silicone. Individual calcite crystals exhibit asymmetrical dumbbell shapes and are prepared by a parallel tectonic approach under ambient conditions. Furthermore, the silicone matrix immobilizes the epitaxial nucleation sites through self-templated cavities, which enables symmetry breaking in reactionmore » dynamics and scalable manipulation of the mineral ensembles. With this platform, we devise several mineral-enabled dynamic surfaces and interfaces. For example, we show that the induced growth of minerals yields localized inorganic adhesion for biological tissue and reversible focal encapsulation for sensitive components in flexible electronics.« less

Sub-wavelength InAs quantum dot micro-disk lasers epitaxially grown on exact Si (001) substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wan, Yating; Li, Qiang; Lau, Kei May, E-mail: eekmlau@ust.hk

Subwavelength micro-disk lasers (MDLs) as small as 1 μm in diameter on exact (001) silicon were fabricated using colloidal lithography. The micro-cavity gain medium incorporating five-stacked InAs quantum dot layers was grown on a high crystalline quality GaAs-on-V-grooved-Si template with no absorptive intermediate buffers. Under continuous-wave optical pumping, the MDLs on silicon exhibit lasing in the 1.2-μm wavelength range with low thresholds down to 35 μW at 10 K. The MDLs compare favorably with devices fabricated on native GaAs substrates and state-of-the-art work reported elsewhere. Feasibility of device miniaturization can be projected by size-dependent lasing characteristics. The results show a promising path towardsmore » dense integration of photonic components on the mainstream complementary metal–oxide–semiconductor platform.« less

Silicon on-chip bandpass filters for the multiplexing of high sensitivity photonic crystal microcavity biosensors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Hai, E-mail: hai.yan@utexas.edu; Zou, Yi; Yang, Chun-Ju

A method for the dense integration of high sensitivity photonic crystal (PC) waveguide based biosensors is proposed and experimentally demonstrated on a silicon platform. By connecting an additional PC waveguide filter to a PC microcavity sensor in series, a transmission passband is created, containing the resonances of the PC microcavity for sensing purpose. With proper engineering of the passband, multiple high sensitivity PC microcavity sensors can be integrated into microarrays and be interrogated simultaneously between a single input and a single output port. The concept was demonstrated with a 2-channel L55 PC biosensor array containing PC waveguide filters. The experimentmore » showed that the sensors on both channels can be monitored simultaneously from a single output spectrum. Less than 3 dB extra loss for the additional PC waveguide filter is observed.« less

A low-power high-speed ultra-wideband pulse radio transmission system.

PubMed

Wei Tang; Culurciello, E

2009-10-01

We present a low-power high-speed ultra-wideband (UWB) transmitter with a wireless transmission test platform. The system is specifically designed for low-power high-speed wireless implantable biosensors. The integrated transmitter consists of a compact pulse generator and a modulator. The circuit is fabricated in the 0.5-mum silicon-on-sapphire process and occupies 420 mum times 420 mum silicon area. The transmitter is capable of generating pulses with 1-ns width and the pulse rate can be controlled between 90 MHz and 270 MHz. We built a demonstration/testing system for the transmitter. The transmitter achieves a 14-Mb/s data rate. With 50% duty cycle data, the power consumption of the chip is between 10 mW and 21 mW when the transmission distance is from 3.2 to 4 m. The core circuit size is 70 mum times 130 mum.

Low-Actuation Voltage MEMS Digital-to-Analog Converter with Parylene Spring Structures

PubMed Central

Ma, Cheng-Wen; Lee, Fu-Wei; Liao, Hsin-Hung; Kuo, Wen-Cheng; Yang, Yao-Joe

2015-01-01

We propose an electrostatically-actuated microelectromechanical digital-to-analog converter (M-DAC) device with low actuation voltage. The spring structures of the silicon-based M-DAC device were monolithically fabricated using parylene-C. Because the Young’s modulus of parylene-C is considerably lower than that of silicon, the electrostatic microactuators in the proposed device require much lower actuation voltages. The actuation voltage of the proposed M-DAC device is approximately 6 V, which is less than one half of the actuation voltages of a previously reported M-DAC equipped with electrostatic microactuators. The measured total displacement of the proposed three-bit M-DAC is nearly 504 nm, and the motion step is approximately 72 nm. Furthermore, we demonstrated that the M-DAC can be employed as a mirror platform with discrete displacement output for a noncontact surface profiling system. PMID:26343682

Thermo-optic coefficient and nonlinear refractive index of silicon oxynitride waveguides

NASA Astrophysics Data System (ADS)

Trenti, A.; Borghi, M.; Biasi, S.; Ghulinyan, M.; Ramiro-Manzano, F.; Pucker, G.; Pavesi, L.

2018-02-01

Integrated waveguiding devices based on silicon oxynitride (SiON) are appealing for their relatively high refractive index contrast and broadband transparency. The lack of two photon absorption at telecom wavelengths and the possibility to fabricate low loss waveguides make SiON an ideal platform for on-chip nonlinear optics and for the realization of reconfigurable integrated quantum lightwave circuits. Despite this, very few studies on its linear and nonlinear optical properties have been reported so far. In this work, we measured the thermo-optic coefficient dn/dT and the nonlinear refractive index n2 of relatively high (n ˜ 1.83 at a wavelength of 1.55 μm) refractive index SiON by using racetrack resonators. These parameters have been determined to be d/n d T =(1.84 ±0.17 ) × 10-5 K-1 and n2 = (7 ± 1) × 10-16 cm2W-1.

Monolithic photonic integrated circuit with a GaN-based bent waveguide

NASA Astrophysics Data System (ADS)

Cai, Wei; Qin, Chuan; Zhang, Shuai; Yuan, Jialei; Zhang, Fenghua; Wang, Yongjin

2018-06-01

Integration of a transmitter, waveguide and receiver into a single chip can generate a multicomponent system with multiple functionalities. Here, we fabricate and characterize a GaN-based photonic integrated circuit (PIC) on a GaN-on-silicon platform. With removal of the silicon and back wafer thinning of the epitaxial film, ultrathin membrane-type devices and highly confined suspended GaN waveguides were formed. Two suspended-membrane InGaN/GaN multiple-quantum-well diodes (MQW-diodes) served as an MQW light-emitting diode (MQW-LED) to emit light and an MQW photodiode (MQW-PD) to sense light. The optical interconnects between the MQW-LED and MQW-PD were achieved using the GaN bent waveguide. The GaN-based PIC consisting of an MQW-LED, waveguides and an MQW-PD forms an in-plane light communication system with a data transmission rate of 70 Mbps.

Nano-islands integrated evanescence-based lab-on-a-chip on silica-on-silicon and polydimethylsiloxane hybrid platform for detection of recombinant growth hormone

PubMed Central

Ozhikandathil, J.; Packirisamy, M.

2012-01-01

Integration of nano-materials in optical microfluidic devices facilitates the realization of miniaturized analytical systems with enhanced sensing abilities for biological and chemical substances. In this work, a novel method of integration of gold nano-islands in a silica-on-silicon-polydimethylsiloxane microfluidic device is reported. The device works based on the nano-enhanced evanescence technique achieved by interacting the evanescent tail of propagating wave with the gold nano-islands integrated on the core of the waveguide resulting in the modification of the propagating UV-visible spectrum. The biosensing ability of the device is investigated by finite-difference time-domain simulation with a simplified model of the device. The performance of the proposed device is demonstrated for the detection of recombinant growth hormone based on antibody-antigen interaction. PMID:24106526

Bottom-up assembly of metallic germanium

NASA Astrophysics Data System (ADS)

Scappucci, Giordano; Klesse, Wolfgang M.; Yeoh, Lareine A.; Carter, Damien J.; Warschkow, Oliver; Marks, Nigel A.; Jaeger, David L.; Capellini, Giovanni; Simmons, Michelle Y.; Hamilton, Alexander R.

2015-08-01

Extending chip performance beyond current limits of miniaturisation requires new materials and functionalities that integrate well with the silicon platform. Germanium fits these requirements and has been proposed as a high-mobility channel material, a light emitting medium in silicon-integrated lasers, and a plasmonic conductor for bio-sensing. Common to these diverse applications is the need for homogeneous, high electron densities in three-dimensions (3D). Here we use a bottom-up approach to demonstrate the 3D assembly of atomically sharp doping profiles in germanium by a repeated stacking of two-dimensional (2D) high-density phosphorus layers. This produces high-density (1019 to 1020 cm-3) low-resistivity (10-4Ω · cm) metallic germanium of precisely defined thickness, beyond the capabilities of diffusion-based doping technologies. We demonstrate that free electrons from distinct 2D dopant layers coalesce into a homogeneous 3D conductor using anisotropic quantum interference measurements, atom probe tomography, and density functional theory.

Resonantly driven CNOT gate for electron spins.

PubMed

Zajac, D M; Sigillito, A J; Russ, M; Borjans, F; Taylor, J M; Burkard, G; Petta, J R

2018-01-26

Single-qubit rotations and two-qubit CNOT operations are crucial ingredients for universal quantum computing. Although high-fidelity single-qubit operations have been achieved using the electron spin degree of freedom, realizing a robust CNOT gate has been challenging because of rapid nuclear spin dephasing and charge noise. We demonstrate an efficient resonantly driven CNOT gate for electron spins in silicon. Our platform achieves single-qubit rotations with fidelities greater than 99%, as verified by randomized benchmarking. Gate control of the exchange coupling allows a quantum CNOT gate to be implemented with resonant driving in ~200 nanoseconds. We used the CNOT gate to generate a Bell state with 78% fidelity (corrected for errors in state preparation and measurement). Our quantum dot device architecture enables multi-qubit algorithms in silicon. Copyright © 2018, The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Towards a 'siliconeural computer': technological successes and challenges.

PubMed

Hughes, Mark A; Shipston, Mike J; Murray, Alan F

2015-07-28

Electronic signals govern the function of both nervous systems and computers, albeit in different ways. As such, hybridizing both systems to create an iono-electric brain-computer interface is a realistic goal; and one that promises exciting advances in both heterotic computing and neuroprosthetics capable of circumventing devastating neuropathology. 'Neural networks' were, in the 1980s, viewed naively as a potential panacea for all computational problems that did not fit well with conventional computing. The field bifurcated during the 1990s into a highly successful and much more realistic machine learning community and an equally pragmatic, biologically oriented 'neuromorphic computing' community. Algorithms found in nature that use the non-synchronous, spiking nature of neuronal signals have been found to be (i) implementable efficiently in silicon and (ii) computationally useful. As a result, interest has grown in techniques that could create mixed 'siliconeural' computers. Here, we discuss potential approaches and focus on one particular platform using parylene-patterned silicon dioxide.

3D calcite heterostructures for dynamic and deformable mineralized matrices

DOE PAGES

Yi, Jaeseok; Wang, Yucai; Jiang, Yuanwen; ...

2017-09-11

Scales are rooted in soft tissues, and are regenerated by specialized cells. The realization of dynamic synthetic analogues with inorganic materials has been a significant challenge, because the abiological regeneration sites that could yield deterministic growth behavior are hard to form. Here we overcome this fundamental hurdle by constructing a mutable and deformable array of three-dimensional calcite heterostructures that are partially locked in silicone. Individual calcite crystals exhibit asymmetrical dumbbell shapes and are prepared by a parallel tectonic approach under ambient conditions. Furthermore, the silicone matrix immobilizes the epitaxial nucleation sites through self-templated cavities, which enables symmetry breaking in reactionmore » dynamics and scalable manipulation of the mineral ensembles. With this platform, we devise several mineral-enabled dynamic surfaces and interfaces. For example, we show that the induced growth of minerals yields localized inorganic adhesion for biological tissue and reversible focal encapsulation for sensitive components in flexible electronics.« less

Superhydrophobic Silicon Nanocrystal-Silica Aerogel Hybrid Materials: Synthesis, Properties, and Sensing Application.

PubMed

Kehrle, Julian; Purkait, Tapas K; Kaiser, Simon; Raftopoulos, Konstantinos N; Winnacker, Malte; Ludwig, Theresa; Aghajamali, Maryam; Hanzlik, Marianne; Rodewald, Katia; Helbich, Tobias; Papadakis, Christine M; Veinot, Jonathan G C; Rieger, Bernhard

2018-04-24

Silicon nanocrystals (SiNCs) are abundant and exhibit exquisitely tailorable optoelectronic properties. The incorporation of SiNCs into highly porous and lightweight substrates such as aerogels leads to hybrid materials possessing the attractive features of both materials. This study describes the covalent deposition of SiNCs on and intercalation into silica aerogels, explores the properties, and demonstrates a prototype sensing application of the composite material. SiNCs of different sizes were functionalized with triethoxyvinylsilane (TEVS) via a radical grafting approach and subsequently used for the synthesis of photoluminescent silica hybrids. The resulting SiNC-containing aerogels possess high porosities, SiNC-based size-dependent photoluminescence, transparency, and a superhydrophobic macroscopic surface. The materials were used to examine the photoluminescence response toward low concentrations of 3-nitrotoluene (270 μM), demonstrating their potential as a sensing platform for high-energy materials.

Design and fabrication of hybrid SPP waveguides for ultrahigh-bandwidth low-penalty terabit-scale data transmission.

PubMed

Du, Jing; Wang, Jian

2017-11-27

Here we design and fabricate a hybrid surface plasmon polarities (SPP) waveguide on the silicon-on-insulator (SOI) photonics platform. The designed hybrid SPP waveguide is composed of a metal ridge, an air gap, and a silicon ridge. We simulate the mode characteristics in the structure and design the waveguide with a wide air gap that can simplify the fabrication process and maintain the advantages of the hybrid SPP mode. The performance of ultrahigh-bandwidth data transmission through the proposed waveguide is then investigated using 161 wavelength-division multiplexing (WDM) channels, each carrying a 11.2-Gbit/s orthogonal frequency-division multiplexing (OFDM) 16-ary quadrature amplitude modulation (16-QAM) signal. The bit-error rates (BERs) of all 161 channels are less than 1e-3. The favorable results show the prospect of on-chip optical interconnection using the proposed hybrid SPP waveguide.

Porous silicon platform for optical detection of functionalized magnetic particles biosensing.

PubMed

Ko, Pil Ju; Ishikawa, Ryousuke; Sohn, Honglae; Sandhu, Adarsh

2013-04-01

The physical properties of porous materials are being exploited for a wide range of applications including optical biosensors, waveguides, gas sensors, micro capacitors, and solar cells. Here, we review the fast, easy and inexpensive electrochemical anodization based fabrication porous silicon (PSi) for optical biosensing using functionalized magnetic particles. Combining magnetically labeled biomolecules with PSi offers a rapid and one-step immunoassay and real-time detection by magnetic manipulation of superparamagnetic beads (SPBs) functionalized with target molecules onto corresponding probe molecules immobilized inside nano-pores of PSi. We first give an introduction to electrochemical and chemical etching procedures used to fabricate a wide range of PSi structures. Next, we describe the basic properties of PSi and underlying optical scattering mechanisms that govern their unique optical properties. Finally, we give examples of our experiments that demonstrate the potential of combining PSi and magnetic beads for real-time point of care diagnostics.

Trace-gas Spectroscopy of Methane on a Silicon Photonic Chip

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Eric; Xiong, Chi; Martin, Yves

Recent advances in hybrid integrated silicon photonic (SiPh) technologies are enabling the migration of conventional free-space optical spectroscopic sensors onto a compact on-chip platform [1-3]. In addition to the small spatial footprint and power efficiency, we envision such sensors to be scalably manufactured using existing CMOS-compatible foundry processes, thus providing disruptive SWaP-C (size, weight, power, and cost) benefits in contrast to commercially available optical sensors. Initial demonstration of evanescent TDLAS (tunable diode laser absorption spectroscopy) of methane (CH4) on a passive SiPh waveguide has indicated minimum fractional absorption of (αL)min = 3.3×10-5 Hz-1/2, which is on-par with state-of-art open-path TDLASmore » sensor systems [4]. Given the general recent movement toward cleaner fuels, CH4 fugitive emissions monitoring is of significant interest given the extremely high radiative forcing potential [5]. For a nominal waveguide length of 30 cm with Γ = 25 % evanescent exposure, this corresponds to ~ 10 ppmv detection sensitivity at 1 s integration time, and further sensitivity enhancement is expected with even longer waveguides, as the laser RIN typically dominates our measurements at nominal waveguide lengths. Despite the excellent sensitivities for short-term integration periods, long-term measurements (> 10 s) are potentially limited on a silicon platform due to the high material thermo-optic coefficient, resulting in significant susceptibility of Fabry-Perot etalons to drift in the presence of even small (~ 1 mK) thermal fluctuations. To this end, customized spectral fitting algorithms have played a significant role in both fringe drift mitigation and peak detection fidelity (e.g. in the presence of a passing CH4 plume), which are crucial for enhancing long-term stability without the need for frequent sensor recalibration. A variety of spectral algorithms have been designed for this purpose, and details will be presented at the meeting.« less

Hybrid optofluidic biosensors

NASA Astrophysics Data System (ADS)

Parks, Joshua W.

Optofluidics, born of the desire to create a system containing microfluidic environments with integrated optical elements, has seen dramatic increases in popularity over the last 10 years. In particular, the application of this technology towards chip based molecular sensors has undergone significant development. The most sensitive of these biosensors interface liquid- and solid-core antiresonant reflecting optical waveguides (ARROWs). These sensor chips are created using conventional silicon microfabrication. As such, ARROW technology has previously been unable to utilize state-of-the-art microfluidic developments because the technology used--soft polydimethyl siloxane (PDMS) micromolded chips--is unamenable to the silicon microfabrication workflows implemented in the creation of ARROW detection chips. The original goal of this thesis was to employ hybrid integration, or the connection of independently designed and fabricated optofluidic and microfluidic chips, to create enhanced biosensors with the capability of processing and detecting biological samples on a single hybrid system. After successful demonstration of this paradigm, this work expanded into a new direction--direct integration of sensing and detection technologies on a new platform with dynamic, multi-dimensional photonic re-configurability. This thesis reports a number of firsts, including: • 1,000 fold optical transmission enhancement of ARROW optofluidic detection chips through thermal annealing, • Detection of single nucleic acids on a silicon-based ARROW chip, • Hybrid optofluidic integration of ARROW detection chips and passive PDMS microfluidic chips, • Hybrid optofluidic integration of ARROW detection chips and actively controllable PDMS microfluidic chips with integrated microvalves, • On-chip concentration and detection of clinical Ebola nucleic acids, • Multimode interference (MMI) waveguide based wavelength division multiplexing for detection of single influenza virions, • All PDMS platform created from monolithically integrated solid- and liquid-core waveguides with single particle detection efficiency and directly integrated microvalves, featuring: ∘ Tunable/tailorable PDMS MMI waveguides, ∘ Lightvalves (optical switch/fluidic microvalve) with the ability to dynamically control light and fluid flow simultaneously, ∘ Lightvalve trap architecture with the ability to physically trap, detect, and analyze single biomolecules.

Military Utility of Multispectral and Hyperspectral Sensors

DTIC Science & Technology

1994-11-01

Resolution) ........ 5-12 5-2. Actual and Modeled Target and Conifer Background Signatures. (a) In the MWIR and (b) in the LW IR...absorption in CO2 at 2.7, 4.2, and 15 Pm, and absorption in silicon dioxide between 8.5 and 10 pm. 2.4 DIRECTIONAL REFLECTANCE, BIDIRECTIONAL...3.39 pm), Nd:YAG (1.06 pm), and CO2 (10.6 pm or 5.3 gm doubled). With a typical goniometric facility, a sample is mounted on a 3 axis platform so that

Monolithic photonic integration for visible and short near-infrared wavelengths: technologies and platforms for bio and life science applications

NASA Astrophysics Data System (ADS)

Porcel, Marco A. G.; Artundo, Iñigo; Domenech, J. David; Geuzebroek, Douwe; Sunarto, Rino; Hoofman, Romano

2018-04-01

This tutorial aims to provide a general overview on the state-of-the-art of photonic integrated circuits (PICs) in the visible and short near-infrared (NIR) wavelength ranges, mostly focusing in silicon nitride (SiN) substrates, and a guide to the necessary steps in the design toward the fabrication of such PICs. The focus is put on bio- and life sciences, given the adequacy and, thus, a large number of applications in this field.

Phase Diversity Wavefront Sensing for Control of Space Based Adaptive Optics Systems

DTIC Science & Technology

2007-12-01

given a cursory review below. 1. The Fast-Steering Mirror or “Tip- Tilt ” mirror is the simplest image corrector. It is capable of correcting for...movements either onboard the optical platform or the majority of atmospherics by applying 2-dimensional offsets in “tip and tilt .” It is used in the...SRDC 3 loop AO system discussed in Chapter V and identified in Figure 24 2. Piezoelectric Deformable Mirrors (PDM’s) use glass, silicon or fused