Contact formation and gettering of precipitated impurities by multiple firing during semiconductor device fabrication

DOEpatents

Sopori, Bhushan

2014-05-27

Methods for contact formation and gettering of precipitated impurities by multiple firing during semiconductor device fabrication are provided. In one embodiment, a method for fabricating an electrical semiconductor device comprises: a first step that includes gettering of impurities from a semiconductor wafer and forming a backsurface field; and a second step that includes forming a front contact for the semiconductor wafer, wherein the second step is performed after completion of the first step.

Hybrid method of making an amorphous silicon P-I-N semiconductor device

DOEpatents

Moustakas, Theodore D.; Morel, Don L.; Abeles, Benjamin

1983-10-04

The invention is directed to a hydrogenated amorphous silicon PIN semiconductor device of hybrid glow discharge/reactive sputtering fabrication. The hybrid fabrication method is of advantage in providing an ability to control the optical band gap of the P and N layers, resulting in increased photogeneration of charge carriers and device output.

Micro-optical elements produced using an photo-embossing technique in photopolymers

NASA Astrophysics Data System (ADS)

O'Neill, Feidhlim T.; Rowsome, Ita C.; Carr, Alun J.; Daniels, Stephen M.; Gleeson, Michael R.; Kelly, John V.; Close, Ciara; Lawrence, Justin R.; Sheridan, John T.

2005-09-01

Micro-optical devices are very important in current high-tech consumer items. The development of future products depends on both the evolution of fabrication techniques and on the development of new low cost mass production methods. Polymers offer ease of fabrication and low cost and are therefore excellent materials for the development of micro-optical devices. Polymer optical devices include passive optical elements, such as microlens arrays and waveguides, as well as active devices such as polymer based lasers. One of the most important areas of micro-optics is that of microlens design, manufacture and testing. The wide diversity of fabrication methods used for the production of these elements indicates their importance. One of these fabrication techniques is photo-embossing. The use of the photo-embossing technique and a photopolymer holographic recording material will be examined in this paper. A discussion of current attempts to model the fabrication process and a review of the experimental method will be given.

Flexible and wearable electronic silk fabrics for human physiological monitoring

NASA Astrophysics Data System (ADS)

Mao, Cuiping; Zhang, Huihui; Lu, Zhisong

2017-09-01

The development of textile-based devices for human physiological monitoring has attracted tremendous interest in recent years. However, flexible physiological sensing elements based on silk fabrics have not been realized. In this paper, ZnO nanorod arrays are grown in situ on reduced graphene oxide-coated silk fabrics via a facile electro-deposition method for the fabrication of silk-fabric-based mechanical sensing devices. The data show that well-aligned ZnO nanorods with hexagonal wurtzite crystalline structures are synthesized on the conductive silk fabric surface. After magnetron sputtering of gold electrodes, silk-fabric-based devices are produced and applied to detect periodic bending and twisting. Based on the electric signals, the deformation and release processes can be easily differentiated. Human arterial pulse and respiration can also be real-time monitored to calculate the pulse rate and respiration frequency, respectively. Throat vibrations during coughing and singing are detected to demonstrate the voice recognition capability. This work may not only help develop silk-fabric-based mechanical sensing elements for potential applications in clinical diagnosis, daily healthcare monitoring and voice recognition, but also provide a versatile method for fabricating textile-based flexible electronic devices.

Light-driven 3D droplet manipulation on flexible optoelectrowetting devices fabricated by a simple spin-coating method.

PubMed

Jiang, Dongyue; Park, Sung-Yong

2016-05-21

Technical advances in electrowetting-on-dielectric (EWOD) over the past few years have extended our attraction to three-dimensional (3D) devices capable of providing more flexibility and functionality with larger volumetric capacity than conventional 2D planar ones. However, typical 3D EWOD devices require complex and expensive fabrication processes for patterning and wiring of pixelated electrodes that also restrict the minimum droplet size to be manipulated. Here, we present a flexible single-sided continuous optoelectrowetting (SCOEW) device which is not only fabricated by a spin-coating method without the need for patterning and wiring processes, but also enables light-driven 3D droplet manipulations. To provide photoconductive properties, previous optoelectrowetting (OEW) devices have used amorphous silicon (a-Si) typically fabricated through high-temperature processes over 300 °C such as CVD or PECVD. However, most of the commercially-available flexible substrates such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) experience serious thermal deformation under such high-temperature processes. Because of this compatibility issue of conventional OEW devices with flexible substrates, light-driven 3D droplet manipulations have not yet been demonstrated on flexible substrates. Our study overcomes this compatibility issue by using a polymer-based photoconductive material, titanium oxide phthalocyanine (TiOPc) and thus SCOEW devices can be simply fabricated on flexible substrates through a low-cost, spin-coating method. In this paper, analytical studies were conducted to understand the effects of light patterns on static contact angles and EWOD forces. For experimental validations of our study, flexible SCOEW devices were successfully fabricated through the TiOPc-based spin-coating method and light-driven droplet manipulations (e.g. transportation, merging, and splitting) have been demonstrated on various 3D terrains such as inclined, vertical, upside-down, and curved surfaces. Our flexible SCOEW technology offers the benefits of device simplicity, flexibility, and functionality over conventional EWOD and OEW devices by enabling optical droplet manipulations on a 3D featureless surface.

Memory effects in a Al/Ti:HfO2/CuPc metal-oxide-semiconductor device

NASA Astrophysics Data System (ADS)

Tripathi, Udbhav; Kaur, Ramneek

2016-05-01

Metal oxide semiconductor structured organic memory device has been successfully fabricated. Ti doped hafnium oxide (Ti:HfO2) nanoparticles has been fabricated by precipitation method and further calcinated at 800 °C. Copper phthalocyanine, a hole transporting material has been utilized as an organic semiconductor. The electrical properties of the fabricated device have been studied by measuring the current-voltage and capacitance-voltage characteristics. The amount of charge stored in the nanoparticles has been calculated by using flat band condition. This simple approach for fabricating MOS memory device has opens up opportunities for the development of next generation memory devices.

Fabricating biomedical origami: a state-of-the-art review.

PubMed

Johnson, Meredith; Chen, Yue; Hovet, Sierra; Xu, Sheng; Wood, Bradford; Ren, Hongliang; Tokuda, Junichi; Tse, Zion Tsz Ho

2017-11-01

Origami-based biomedical device design is an emerging technology due to its ability to be deployed from a minimal foldable pattern to a larger volume. This paper aims to review state-of-the-art origami structures applied in the medical device field. Publications and reports of origami structure related to medical device design from the past 10 years are reviewed and categorized according to engineering specifications, including the application field, fabrication material, size/volume, deployment method, manufacturability, and advantages. This paper presents an overview of the biomedical applications of devices based on origami structures, including disposable sterilization covers, cardiac catheterization, stent grafts, encapsulation and microsurgery, gastrointestinal microsurgery, laparoscopic surgical grippers, microgrippers, microfluidic devices, and drug delivery. Challenges in terms of materials and fabrication, assembly, modeling and computation design, and clinical adoptability are discussed at the end of this paper to provide guidance for future origami-based design in the medical device field. Concepts from origami can be used to design and develop novel medical devices. Origami-based medical device design is currently progressing, with researchers improving design methods, materials, fabrication techniques, and folding efficiency.

Front and backside processed thin film electronic devices

DOEpatents

Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.; Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang

2010-10-12

This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

Fabrication and Characterization of All-Polystyrene Microfluidic Devices with Integrated Electrodes and Tubing.

PubMed

Pentecost, Amber M; Martin, R Scott

2015-01-01

A new method of fabricating all-polystyrene devices with integrated electrodes and fluidic tubing is described. As opposed to expensive polystyrene (PS) fabrication techniques that use hot embossing and bonding with a heated lab press, this approach involves solvent-based etching of channels and lamination-based bonding of a PS cover, all of which do not need to occur in a clean room. PS has been studied as an alternative microchip substrate to PDMS, as it is more hydrophilic, biologically compatible in terms of cell adhesion, and less prone to absorption of hydrophobic molecules. The etching/lamination-based method described here results in a variety of all-PS devices, with or without electrodes and tubing. To characterize the devices, micrographs of etched channels (straight and intersected channels) were taken using confocal and scanning electron microscopy. Microchip-based electrophoresis with repetitive injections of fluorescein was conducted using a three-sided PS (etched pinched, twin-tee channel) and one-sided PDMS device. Microchip-based flow injection analysis, with dopamine and NO as analytes, was used to characterize the performance of all-PS devices with embedded tubing and electrodes. Limits of detection for dopamine and NO were 130 nM and 1.8 μM, respectively. Cell immobilization studies were also conducted to assess all-PS devices for cellular analysis. This paper demonstrates that these easy to fabricate devices can be attractive alternative to other PS fabrication methods for a wide variety of analytical and cell culture applications.

Three-Dimensional Printing Based Hybrid Manufacturing of Microfluidic Devices.

PubMed

Alapan, Yunus; Hasan, Muhammad Noman; Shen, Richang; Gurkan, Umut A

2015-05-01

Microfluidic platforms offer revolutionary and practical solutions to challenging problems in biology and medicine. Even though traditional micro/nanofabrication technologies expedited the emergence of the microfluidics field, recent advances in advanced additive manufacturing hold significant potential for single-step, stand-alone microfluidic device fabrication. One such technology, which holds a significant promise for next generation microsystem fabrication is three-dimensional (3D) printing. Presently, building 3D printed stand-alone microfluidic devices with fully embedded microchannels for applications in biology and medicine has the following challenges: (i) limitations in achievable design complexity, (ii) need for a wider variety of transparent materials, (iii) limited z-resolution, (iv) absence of extremely smooth surface finish, and (v) limitations in precision fabrication of hollow and void sections with extremely high surface area to volume ratio. We developed a new way to fabricate stand-alone microfluidic devices with integrated manifolds and embedded microchannels by utilizing a 3D printing and laser micromachined lamination based hybrid manufacturing approach. In this new fabrication method, we exploit the minimized fabrication steps enabled by 3D printing, and reduced assembly complexities facilitated by laser micromachined lamination method. The new hybrid fabrication method enables key features for advanced microfluidic system architecture: (i) increased design complexity in 3D, (ii) improved control over microflow behavior in all three directions and in multiple layers, (iii) transverse multilayer flow and precisely integrated flow distribution, and (iv) enhanced transparency for high resolution imaging and analysis. Hybrid manufacturing approaches hold great potential in advancing microfluidic device fabrication in terms of standardization, fast production, and user-independent manufacturing.

Three-Dimensional Printing Based Hybrid Manufacturing of Microfluidic Devices

PubMed Central

Shen, Richang; Gurkan, Umut A.

2016-01-01

Microfluidic platforms offer revolutionary and practical solutions to challenging problems in biology and medicine. Even though traditional micro/nanofabrication technologies expedited the emergence of the microfluidics field, recent advances in advanced additive manufacturing hold significant potential for single-step, stand-alone microfluidic device fabrication. One such technology, which holds a significant promise for next generation microsystem fabrication is three-dimensional (3D) printing. Presently, building 3D printed stand-alone microfluidic devices with fully embedded microchannels for applications in biology and medicine has the following challenges: (i) limitations in achievable design complexity, (ii) need for a wider variety of transparent materials, (iii) limited z-resolution, (iv) absence of extremely smooth surface finish, and (v) limitations in precision fabrication of hollow and void sections with extremely high surface area to volume ratio. We developed a new way to fabricate stand-alone microfluidic devices with integrated manifolds and embedded microchannels by utilizing a 3D printing and laser micromachined lamination based hybrid manufacturing approach. In this new fabrication method, we exploit the minimized fabrication steps enabled by 3D printing, and reduced assembly complexities facilitated by laser micromachined lamination method. The new hybrid fabrication method enables key features for advanced microfluidic system architecture: (i) increased design complexity in 3D, (ii) improved control over microflow behavior in all three directions and in multiple layers, (iii) transverse multilayer flow and precisely integrated flow distribution, and (iv) enhanced transparency for high resolution imaging and analysis. Hybrid manufacturing approaches hold great potential in advancing microfluidic device fabrication in terms of standardization, fast production, and user-independent manufacturing. PMID:27512530

Transistors using crystalline silicon devices on glass

DOEpatents

McCarthy, Anthony M.

1995-01-01

A method for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed.

Methods and devices for fabricating three-dimensional nanoscale structures

DOEpatents

Rogers, John A.; Jeon, Seokwoo; Park, Jangung

2010-04-27

The present invention provides methods and devices for fabricating 3D structures and patterns of 3D structures on substrate surfaces, including symmetrical and asymmetrical patterns of 3D structures. Methods of the present invention provide a means of fabricating 3D structures having accurately selected physical dimensions, including lateral and vertical dimensions ranging from 10s of nanometers to 1000s of nanometers. In one aspect, methods are provided using a mask element comprising a conformable, elastomeric phase mask capable of establishing conformal contact with a radiation sensitive material undergoing photoprocessing. In another aspect, the temporal and/or spatial coherence of electromagnetic radiation using for photoprocessing is selected to fabricate complex structures having nanoscale features that do not extend entirely through the thickness of the structure fabricated.

Coaxial cable stripping device facilitates RF cabling fabrication

NASA Technical Reports Server (NTRS)

Hughes, R. S.; Tobias, R. A.

1967-01-01

Coaxial cable stripping device assures clean, right angled shoulder for RF cable connector fabrication. This method requires minimal skill and creates a low voltage standing wave ratio and mechanical stability in the interconnecting RF Cables.

Achieving high performance polymer optoelectronic devices for high efficiency, long lifetime and low fabrication cost

NASA Astrophysics Data System (ADS)

Huang, Jinsong

This thesis described three types of organic optoelectronic devices: polymer light emitting diodes (PLED), polymer photovoltaic solar cell, and organic photo detector. The research in this work focuses improving their performance including device efficiency, operation lifetime simplifying fabrication process. With further understanding in PLED device physics, we come up new device operation model and improved device architecture design. This new method is closely related to understanding of the science and physics at organic/metal oxide and metal oxide/metal interface. In our new device design, both material and interface are considered in order to confine and balance all injected carriers, which has been demonstrated very be successful in increasing device efficiency. We created two world records in device efficiency: 18 lm/W for white emission fluorescence PLED, 22 lm/W for red emission phosphorescence PLED. Slow solvent drying process has been demonstrated to significantly increase device efficiency in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C 61-butyric acid methyl ester (PCBM) mixture polymer solar cell. From the mobility study by time of flight, the increase of efficiency can be well correlated to the improved carrier transport property due to P3HT crystallization during slow solvent drying. And it is found that, similar to PLED, balanced carrier mobility is essential in high efficient polymer solar cell. There is also a revolution in our device fabrication method. A unique device fabrication method is presented by an electronic glue based lamination process combined with interface modification as a one-step polymer solar cell fabrication process. It can completely skip the thermal evaporation process, and benefit device lifetime by several merits: no air reactive. The device obtained is metal free, semi-transparent, flexible, self-encapsulated, and comparable efficiency with that by regular method. We found the photomultiplication (PM) phenomenon in C60 based device accidentally. The high PM factor makes it good candidate for photo detector. The high gain was assigned to the trapped-charge induced enhanced-injection at C60/PEDOT:PSS interface.

Management of overdenture abutments health by an innovative cleaning aid

PubMed Central

Mall, Priyanka; Singh, Kamleshwar; Singh, Saumyendra Vikram; Agrawal, Kaushal Kishor; Siddharth, Ramashanker; Chand, Pooran

2012-01-01

This article describes a method for fabrication of a custom-made device for cleaning dome-shaped overdenture abutments. A kid toothbrush and a rubber cup were used for fabrication of a prophylactic device. After regular use of this device periodontal health status of the overdenture abutments patients improved satisfactorily. PMID:23230248

Microfluidics in the Undergraduate Laboratory: Device Fabrication and an Experiment to Mimic Intravascular Gas Embolism

ERIC Educational Resources Information Center

Jablonski, Erin L.; Vogel, Brandon M.; Cavanagh, Daniel P.; Beers, Kathryn L.

2010-01-01

A method to fabricate microfluidic devices and an experimental protocol to model intravascular gas embolism for undergraduate laboratories are presented. The fabrication process details how to produce masters on glass slides; these masters serve as molds to pattern channels in an elastomeric polymer that can be adhered to a substrate, resulting in…

Transistors using crystalline silicon devices on glass

DOEpatents

McCarthy, A.M.

1995-05-09

A method is disclosed for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed. 13 figs.

Thin film solar cell configuration and fabrication method

DOEpatents

Menezes, Shalini

2009-07-14

A new photovoltaic device configuration based on an n-copper indium selenide absorber and a p-type window is disclosed. A fabrication method to produce this device on flexible or rigid substrates is described that reduces the number of cell components, avoids hazardous materials, simplifies the process steps and hence the costs for high volume solar cell manufacturing.

Compact Layers of Hybrid Halide Perovskites Fabricated via the Aerosol Deposition Process-Uncoupling Material Synthesis and Layer Formation.

PubMed

Panzer, Fabian; Hanft, Dominik; Gujar, Tanaji P; Kahle, Frank-Julian; Thelakkat, Mukundan; Köhler, Anna; Moos, Ralf

2016-04-08

We present the successful fabrication of CH₃NH₃PbI₃ perovskite layers by the aerosol deposition method (ADM). The layers show high structural purity and compactness, thus making them suitable for application in perovskite-based optoelectronic devices. By using the aerosol deposition method we are able to decouple material synthesis from layer processing. Our results therefore allow for enhanced and easy control over the fabrication of perovskite-based devices, further paving the way for their commercialization.

Conductance switching in Ag(2)S devices fabricated by in situ sulfurization.

PubMed

Morales-Masis, M; van der Molen, S J; Fu, W T; Hesselberth, M B; van Ruitenbeek, J M

2009-03-04

We report a simple and reproducible method to fabricate switchable Ag(2)S devices. The alpha-Ag(2)S thin films are produced by a sulfurization process after silver deposition on an Si substrate. Structure and composition of the Ag(2)S are characterized using XRD and RBS. Our samples show semiconductor behaviour at low bias voltages, whereas they exhibit reproducible bipolar resistance switching at higher bias voltages. The transition between both types of behaviour is observed by hysteresis in the I-V curves, indicating decomposition of the Ag(2)S, increasing the Ag(+) ion mobility. The as-fabricated Ag(2)S samples are a good candidate for future solid state memory devices, as they show reproducible memory resistive properties and they are fabricated by an accessible and reliable method.

Solving the shrinkage-induced PDMS alignment registration issue in multilayer soft lithography

NASA Astrophysics Data System (ADS)

Moraes, Christopher; Sun, Yu; Simmons, Craig A.

2009-06-01

Shrinkage of polydimethylsiloxane (PDMS) complicates alignment registration between layers during multilayer soft lithography fabrication. This often hinders the development of large-scale microfabricated arrayed devices. Here we report a rapid method to construct large-area, multilayered devices with stringent alignment requirements. This technique, which exploits a previously unrecognized aspect of sandwich mold fabrication, improves device yield, enables highly accurate alignment over large areas of multilayered devices and does not require strict regulation of fabrication conditions or extensive calibration processes. To demonstrate this technique, a microfabricated Braille display was developed and characterized. High device yield and accurate alignment within 15 µm were achieved over three layers for an array of 108 Braille units spread over a 6.5 cm2 area, demonstrating the fabrication of well-aligned devices with greater ease and efficiency than previously possible.

Recent progress in the assembly of nanodevices and van der Waals heterostructures by deterministic placement of 2D materials.

PubMed

Frisenda, Riccardo; Navarro-Moratalla, Efrén; Gant, Patricia; Pérez De Lara, David; Jarillo-Herrero, Pablo; Gorbachev, Roman V; Castellanos-Gomez, Andres

2018-01-02

Designer heterostructures can now be assembled layer-by-layer with unmatched precision thanks to the recently developed deterministic placement methods to transfer two-dimensional (2D) materials. This possibility constitutes the birth of a very active research field on the so-called van der Waals heterostructures. Moreover, these deterministic placement methods also open the door to fabricate complex devices, which would be otherwise very difficult to achieve by conventional bottom-up nanofabrication approaches, and to fabricate fully-encapsulated devices with exquisite electronic properties. The integration of 2D materials with existing technologies such as photonic and superconducting waveguides and fiber optics is another exciting possibility. Here, we review the state-of-the-art of the deterministic placement methods, describing and comparing the different alternative methods available in the literature, and we illustrate their potential to fabricate van der Waals heterostructures, to integrate 2D materials into complex devices and to fabricate artificial bilayer structures where the layers present a user-defined rotational twisting angle.

Utilising three-dimensional printing techniques when providing unique assistive devices: A case report.

PubMed

Day, Sarah Jane; Riley, Shaun Patrick

2018-02-01

The evolution of three-dimensional printing into prosthetics has opened conversations about the availability and cost of prostheses. This report will discuss how a prosthetic team incorporated additive manufacture techniques into the treatment of a patient with a partial hand amputation to create and test a unique assistive device which he could use to hold his French horn. Case description and methods: Using a process of shape capture, photogrammetry, computer-aided design and finite element analysis, a suitable assistive device was designed and tested. The design was fabricated using three-dimensional printing. Patient satisfaction was measured using a Pugh's Matrix™, and a cost comparison was made between the process used and traditional manufacturing. Findings and outcomes: Patient satisfaction was high. The three-dimensional printed devices were 56% cheaper to fabricate than a similar laminated device. Computer-aided design and three-dimensional printing proved to be an effective method for designing, testing and fabricating a unique assistive device. Clinical relevance CAD and 3D printing techniques can enable devices to be designed, tested and fabricated cheaper than when using traditional techniques. This may lead to improvements in quality and accessibility.

Printing-based fabrication method using sacrificial paper substrates for flexible and wearable microfluidic devices

NASA Astrophysics Data System (ADS)

Chung, Daehan; Gray, Bonnie L.

2017-11-01

We present a simple, fast, and inexpensive new printing-based fabrication process for flexible and wearable microfluidic channels and devices. Microfluidic devices are fabricated on textiles (fabric) for applications in clothing-based wearable microfluidic sensors and systems. The wearable and flexible microfluidic devices are comprised of water-insoluable screen-printable plastisol polymer. Sheets of paper are used as sacrificial substrates for multiple layers of polymer on the fabric’s surface. Microfluidic devices can be made within a short time using simple processes and inexpensive equipment that includes a laser cutter and a thermal laminator. The fabrication process is characterized to demonstrate control of microfluidic channel thickness and width. Film thickness smaller than 100 micrometers and lateral dimensions smaller than 150 micrometers are demonstrated. A flexible microfluidic mixer is also developed on fabric and successfully tested on both flat and curved surfaces at volumetric flow rates ranging from 5.5-46 ml min-1.

Two-photon reduction: a cost-effective method for fabrication of functional metallic nanostructures

NASA Astrophysics Data System (ADS)

Tabrizi, Sahar; Cao, YaoYu; Lin, Han; Jia, BaoHua

2017-03-01

Metallic nanostructures have underpinned plasmonic-based advanced photonic devices in a broad range of research fields over the last decade including physics, engineering, material science and bioscience. The key to realizing functional plasmonic resonances that can manipulate light at the optical frequencies relies on the creation of conductive metallic structures at the nanoscale with low structural defects. Currently, most plasmonic nanostructures are fabricated either by electron beam lithography (EBL) or by focused ion beam (FIB) milling, which are expensive, complicated and time-consuming. In comparison, the direct laser writing (DLW) technique has demonstrated its high spatial resolution and cost-effectiveness in three-dimensional fabrication of micro/nanostructures. Furthermore, the recent breakthroughs in superresolution nanofabrication and parallel writing have significantly advanced the fabrication resolution and throughput of the DLW method and made it one of the promising future nanofabrication technologies with low-cost and scalability. In this review, we provide a comprehensive summary of the state-of-the-art DLW fabrication technology for nanometer scale metallic structures. The fabrication mechanisms, different material choices, fabrication capability, including resolution, conductivity and structure surface smoothness, as well as the characterization methods and achievable devices for different applications are presented. In particular, the development trends of the field and the perspectives for future opportunities and challenges are provided at the end of the review. It has been demonstrated that the quality of the metallic structures fabricated using the DLW method is excellent compared with other methods providing a new and enabling platform for functional nanophotonic device fabrication.

Method of fabricating an optoelectronic device having a bulk heterojunction

DOEpatents

Shtein, Max [Ann Arbor, MI; Yang, Fan [Princeton, NJ; Forrest, Stephen R [Princeton, NJ

2008-10-14

A method of fabricating an optoelectronic device comprises: depositing a first layer having protrusions over a first electrode, in which the first layer comprises a first organic small molecule material; depositing a second layer on the first layer such that the second layer is in physical contact with the first layer; in which the smallest lateral dimension of the protrusions are between 1 to 5 times the exciton diffusion length of the first organic small molecule material; and depositing a second electrode over the second layer to form the optoelectronic device. A method of fabricating an organic optoelectronic device having a bulk heterojunction is also provided and comprises: depositing a first layer with protrusions over an electrode by organic vapor phase deposition; depositing a second layer on the first layer where the interface of the first and second layers forms a bulk heterojunction; and depositing another electrode over the second layer.

Enhancement of Light Absorption in Silicon Nanowire Photovoltaic Devices with Dielectric and Metallic Grating Structures.

PubMed

Park, Jin-Sung; Kim, Kyoung-Ho; Hwang, Min-Soo; Zhang, Xing; Lee, Jung Min; Kim, Jungkil; Song, Kyung-Deok; No, You-Shin; Jeong, Kwang-Yong; Cahoon, James F; Kim, Sun-Kyung; Park, Hong-Gyu

2017-12-13

We report the enhancement of light absorption in Si nanowire photovoltaic devices with one-dimensional dielectric or metallic gratings that are fabricated by a damage-free, precisely aligning, polymer-assisted transfer method. Incorporation of a Si 3 N 4 grating with a Si nanowire effectively enhances the photocurrents for transverse-electric polarized light. The wavelength at which a maximum photocurrent is generated is readily tuned by adjusting the grating pitch. Moreover, the electrical properties of the nanowire devices are preserved before and after transferring the Si 3 N 4 gratings onto Si nanowires, ensuring that the quality of pristine nanowires is not degraded during the transfer. Furthermore, we demonstrate Si nanowire photovoltaic devices with Ag gratings using the same transfer method. Measurements on the fabricated devices reveal approximately 27.1% enhancement in light absorption compared to that of the same devices without the Ag gratings without any degradation of electrical properties. We believe that our polymer-assisted transfer method is not limited to the fabrication of grating-incorporated nanowire photovoltaic devices but can also be generically applied for the implementation of complex nanoscale structures toward the development of multifunctional optoelectronic devices.

Microcrystalline silicon thin-film transistors for large area electronic applications

NASA Astrophysics Data System (ADS)

Chan, Kah-Yoong; Bunte, Eerke; Knipp, Dietmar; Stiebig, Helmut

2007-11-01

Thin-film transistors (TFTs) based on microcrystalline silicon (µc-Si:H) exhibit high charge carrier mobilities exceeding 35 cm2 V-1 s-1. The devices are fabricated by plasma-enhanced chemical vapor deposition at substrate temperatures below 200 °C. The fabrication process of the µc-Si:H TFTs is similar to the low temperature fabrication of amorphous silicon TFTs. The electrical characteristics of the µc-Si:H-based transistors will be presented. As the device charge carrier mobility of short channel TFTs is limited by the contacts, the influence of the drain and source contacts on the device parameters including the device charge carrier mobility and the device threshold voltage will be discussed. The experimental data will be described by a modified standard transistor model which accounts for the contact effects. Furthermore, the transmission line method was used to extract the device parameters including the contact resistance. The modified standard transistor model and the transmission line method will be compared in terms of the extracted device parameters and contact resistances.

Method of fabricating a back-contact solar cell and device thereof

DOEpatents

Li, Bo; Smith, David; Cousins, Peter

2014-07-29

Methods of fabricating back-contact solar cells and devices thereof are described. A method of fabricating a back-contact solar cell includes forming an N-type dopant source layer and a P-type dopant source layer above a material layer disposed above a substrate. The N-type dopant source layer is spaced apart from the P-type dopant source layer. The N-type dopant source layer and the P-type dopant source layer are heated. Subsequently, a trench is formed in the material layer, between the N-type and P-type dopant source layers.

Method of fabricating a back-contact solar cell and device thereof

DOEpatents

Li, Bo; Smith, David; Cousins, Peter

2016-08-02

Methods of fabricating back-contact solar cells and devices thereof are described. A method of fabricating a back-contact solar cell includes forming an N-type dopant source layer and a P-type dopant source layer above a material layer disposed above a substrate. The N-type dopant source layer is spaced apart from the P-type dopant source layer. The N-type dopant source layer and the P-type dopant source layer are heated. Subsequently, a trench is formed in the material layer, between the N-type and P-type dopant source layers.

One-step sol-gel imprint lithography for guided-mode resonance structures.

PubMed

Huang, Yin; Liu, Longju; Johnson, Michael; C Hillier, Andrew; Lu, Meng

2016-03-04

Guided-mode resonance (GMR) structures consisting of sub-wavelength periodic gratings are capable of producing narrow-linewidth optical resonances. This paper describes a sol-gel-based imprint lithography method for the fabrication of submicron 1D and 2D GMR structures. This method utilizes a patterned polydimethylsiloxane (PDMS) mold to fabricate the grating coupler and waveguide for a GMR device using a sol-gel thin film in a single step. An organic-inorganic hybrid sol-gel film was selected as the imprint material because of its relatively high refractive index. The optical responses of several sol-gel GMR devices were characterized, and the experimental results were in good agreement with the results of electromagnetic simulations. The influence of processing parameters was investigated in order to determine how finely the spectral response and resonant wavelength of the GMR devices could be tuned. As an example potential application, refractometric sensing experiments were performed using a 1D sol-gel device. The results demonstrated a refractive index sensitivity of 50 nm/refractive index unit. This one-step fabrication process offers a simple, rapid, and low-cost means of fabricating GMR structures. We anticipate that this method can be valuable in the development of various GMR-based devices as it can readily enable the fabrication of complex shapes and allow the doping of optically active materials into sol-gel thin film.

Solid-state curved focal plane arrays

NASA Technical Reports Server (NTRS)

Jones, Todd (Inventor); Nikzad, Shouleh (Inventor); Hoenk, Michael (Inventor)

2010-01-01

The present invention relates to curved focal plane arrays. More specifically, the present invention relates to a system and method for making solid-state curved focal plane arrays from standard and high-purity devices that may be matched to a given optical system. There are two ways to make a curved focal plane arrays starting with the fully fabricated device. One way, is to thin the device and conform it to a curvature. A second way, is to back-illuminate a thick device without making a thinned membrane. The thick device is a special class of devices; for example devices fabricated with high purity silicon. One surface of the device (the non VLSI fabricated surface, also referred to as the back surface) can be polished to form a curved surface.

Design and fabrication of multimode interference couplers based on digital micro-mirror system

NASA Astrophysics Data System (ADS)

Wu, Sumei; He, Xingdao; Shen, Chenbo

2008-03-01

Multimode interference (MMI) couplers, based on the self-imaging effect (SIE), are accepted popularly in integrated optics. According to the importance of MMI devices, in this paper, we present a novel method to design and fabricate MMI couplers. A technology of maskless lithography to make MMI couplers based on a smart digital micro-mirror device (DMD) system is proposed. A 1×4 MMI device is designed as an example, which shows the present method is efficient and cost-effective.

Scalable fabrication of nanowire photonic and electronic circuits using spin-on glass.

PubMed

Zimmler, Mariano A; Stichtenoth, Daniel; Ronning, Carsten; Yi, Wei; Narayanamurti, Venkatesh; Voss, Tobias; Capasso, Federico

2008-06-01

We present a method which can be used for the mass-fabrication of nanowire photonic and electronic devices based on spin-on glass technology and on the photolithographic definition of independent electrical contacts to the top and the bottom of a nanowire. This method allows for the fabrication of nanowire devices in a reliable, fast, and low cost way, and it can be applied to nanowires with arbitrary cross section and doping type (p and n). We demonstrate this technique by fabricating single-nanowire p-Si(substrate)-n-ZnO(nanowire) heterojunction diodes, which show good rectification properties and, furthermore, which function as ultraviolet light-emitting diodes.

Benchtop fabrication of three-dimensional reconfigurable microfluidic devices from paper-polymer composite.

PubMed

Han, Yu Long; Wang, Wenqi; Hu, Jie; Huang, Guoyou; Wang, Shuqi; Lee, Won Gu; Lu, Tian Jian; Xu, Feng

2013-12-21

We presented a benchtop technique that can fabricate reconfigurable, three-dimensional (3D) microfluidic devices made from a soft paper-polymer composite. This fabrication approach can produce microchannels at a minimal width of 100 μm and can be used to prototype 3D microfluidic devices by simple bending and stretching. The entire fabrication process can be finished in 2 hours on a laboratory bench without the need for special equipment involved in lithography. Various functional microfluidic devices (e.g., droplet generator and reconfigurable electronic circuit) were prepared using this paper-polymer hybrid microfluidic system. The developed method can be applied in a wide range of standard applications and emerging technologies such as liquid-phase electronics.

Fabrication of a Paper-Based Microfluidic Device to Readily Determine Nitrite Ion Concentration by Simple Colorimetric Assay

ERIC Educational Resources Information Center

Wang, Bo; Lin, Zhiqiang; Wang, Min

2015-01-01

Paper-based microfluidic devices (µPAD) are a burgeoning platform of microfluidic analysis technology. The method described herein is for use in undergraduate and high school chemistry laboratories. A simple and convenient µPAD was fabricated by easy patterning of filter paper using a permanent marker pen. The usefulness of the device was…

Graphene devices based on laser scribing technology

NASA Astrophysics Data System (ADS)

Qiao, Yan-Cong; Wei, Yu-Hong; Pang, Yu; Li, Yu-Xing; Wang, Dan-Yang; Li, Yu-Tao; Deng, Ning-Qin; Wang, Xue-Feng; Zhang, Hai-Nan; Wang, Qian; Yang, Zhen; Tao, Lu-Qi; Tian, He; Yang, Yi; Ren, Tian-Ling

2018-04-01

Graphene with excellent electronic, thermal, optical, and mechanical properties has great potential applications. The current devices based on graphene grown by micromechanical exfoliation, chemical vapor deposition (CVD), and thermal decomposition of silicon carbide are still expensive and inefficient. Laser scribing technology, a low-cost and time-efficient method of fabricating graphene, is introduced in this review. The patterning of graphene can be directly performed on solid and flexible substrates. Therefore, many novel devices such as strain sensors, acoustic devices, memory devices based on laser scribing graphene are fabricated. The outlook and challenges of laser scribing technology have also been discussed. Laser scribing may be a potential way of fabricating wearable and integrated graphene systems in the future.

Large scale integration of graphene transistors for potential applications in the back end of the line

NASA Astrophysics Data System (ADS)

Smith, A. D.; Vaziri, S.; Rodriguez, S.; Östling, M.; Lemme, M. C.

2015-06-01

A chip to wafer scale, CMOS compatible method of graphene device fabrication has been established, which can be integrated into the back end of the line (BEOL) of conventional semiconductor process flows. In this paper, we present experimental results of graphene field effect transistors (GFETs) which were fabricated using this wafer scalable method. The carrier mobilities in these transistors reach up to several hundred cm2 V-1 s-1. Further, these devices exhibit current saturation regions similar to graphene devices fabricated using mechanical exfoliation. The overall performance of the GFETs can not yet compete with record values reported for devices based on mechanically exfoliated material. Nevertheless, this large scale approach is an important step towards reliability and variability studies as well as optimization of device aspects such as electrical contacts and dielectric interfaces with statistically relevant numbers of devices. It is also an important milestone towards introducing graphene into wafer scale process lines.

Electronic interconnects and devices with topological surface states and methods for fabricating same

DOEpatents

Yazdani, Ali; Ong, N. Phuan; Cava, Robert J.

2017-04-04

An interconnect is disclosed with enhanced immunity of electrical conductivity to defects. The interconnect includes a material with charge carriers having topological surface states. Also disclosed is a method for fabricating such interconnects. Also disclosed is an integrated circuit including such interconnects. Also disclosed is a gated electronic device including a material with charge carriers having topological surface states.

Electronic interconnects and devices with topological surface states and methods for fabricating same

DOEpatents

Yazdani, Ali; Ong, N. Phuan; Cava, Robert J.

2016-05-03

An interconnect is disclosed with enhanced immunity of electrical conductivity to defects. The interconnect includes a material with charge carriers having topological surface states. Also disclosed is a method for fabricating such interconnects. Also disclosed is an integrated circuit including such interconnects. Also disclosed is a gated electronic device including a material with charge carriers having topological surface states.

Method of Fabricating NASA-Standard Macro-Fiber Composite Piezoelectric Actuators

NASA Technical Reports Server (NTRS)

High, James W.; Wilkie, W. Keats

2003-01-01

The NASA Macro-Fiber Composite actuator is a flexible piezoelectric composite device designed for controlling vibrations and shape deformations in high performance aerospace structures. A complete method for fabricating the standard NASA Macro-Fiber Composite actuator is presented in this document. When followed precisely, these procedures will yield devices with electromechanical properties identical to the standard actuator manufactured by NASA Langley Research Center.

A Simple and Scalable Fabrication Method for Organic Electronic Devices on Textiles.

PubMed

Ismailov, Usein; Ismailova, Esma; Takamatsu, Seiichi

2017-03-13

Today, wearable electronics devices combine a large variety of functional, stretchable, and flexible technologies. However, in many cases, these devices cannot be worn under everyday conditions. Therefore, textiles are commonly considered the best substrate to accommodate electronic devices in wearable use. In this paper, we describe how to selectively pattern organic electroactive materials on textiles from a solution in an easy and scalable manner. This versatile deposition technique enables the fabrication of wearable organic electronic devices on clothes.

Direct metal transfer printing on flexible substrate for fabricating optics functional devices

NASA Astrophysics Data System (ADS)

Jiang, Yingjie; Zhou, Xiaohong; Zhang, Feng; Shi, Zhenwu; Chen, Linsen; Peng, Changsi

2015-11-01

New functional materials and devices based on metal patterns can be widely used in many new and expanding industries,such as flat panel displays, alternative energy,sensors and so on. In this paper, we introduce a new transfer printing method for fabricating metal optics functional devices. This method can directly transfer a metal pattern from a polyethylene terephthalate (PET)supported UV or polydimethylsiloxane (PDMS) pattern to another PET substrate. Purely taking advantage of the anaerobic UV curing adhesive (a-UV) on PET substrate, metal film can be easily peeled off from micro/nano-structured surface. As a result, metal film on the protrusion can be selectively transferred onto the target substrate, to make it the metal functional surface. But which on the bottom can not be transferred. This method provides low cost fabrication of metal thin film devices by avoiding high cost lithography process. Compared with conventional approach, this method can get more smooth rough edges and has wider tolerance range for the original master mold. Future developments and potential applications of this metal transfer method will be addressed.

Improved Method of Manufacturing SiC Devices

NASA Technical Reports Server (NTRS)

Okojie, Robert S.

2005-01-01

The phrase, "common-layered architecture for semiconductor silicon carbide" ("CLASSiC") denotes a method of batch fabrication of microelectromechanical and semiconductor devices from bulk silicon carbide. CLASSiC is the latest in a series of related methods developed in recent years in continuing efforts to standardize SiC-fabrication processes. CLASSiC encompasses both institutional and technological innovations that can be exploited separately or in combination to make the manufacture of SiC devices more economical. Examples of such devices are piezoresistive pressure sensors, strain gauges, vibration sensors, and turbulence-intensity sensors for use in harsh environments (e.g., high-temperature, high-pressure, corrosive atmospheres). The institutional innovation is to manufacture devices for different customers (individuals, companies, and/or other entities) simultaneously in the same batch. This innovation is based on utilization of the capability for fabrication, on the same substrate, of multiple SiC devices having different functionalities (see figure). Multiple customers can purchase shares of the area on the same substrate, each customer s share being apportioned according to the customer s production-volume requirement. This makes it possible for multiple customers to share costs in a common foundry, so that the capital equipment cost per customer in the inherently low-volume SiC-product market can be reduced significantly. One of the technological innovations is a five-mask process that is based on an established set of process design rules. The rules provide for standardization of the fabrication process, yet are flexible enough to enable multiple customers to lay out masks for their portions of the SiC substrate to provide for simultaneous batch fabrication of their various devices. In a related prior method, denoted multi-user fabrication in silicon carbide (MUSiC), the fabrication process is based largely on surface micromachining of poly SiC. However, in MUSiC one cannot exploit the superior sensing, thermomechanical, and electrical properties of single-crystal 6H-SiC or 4H-SiC. As a complement to MUSiC, the CLASSiC five-mask process can be utilized to fabricate multiple devices in bulk single-crystal SiC of any polytype. The five-mask process makes fabrication less complex because it eliminates the need for large-area deposition and removal of sacrificial material. Other innovations in CLASSiC pertain to selective etching of indium tin oxide and aluminum in connection with multilayer metallization. One major characteristic of bulk micromachined microelectromechanical devices is the presence of three-dimensional (3D) structures. Any 3D recesses that already exist at a given step in a fabrication process usually make it difficult to apply a planar coat of photoresist for metallization and other subsequent process steps. To overcome this difficulty, the CLASSiC process includes a reversal of part of the conventional flow: Metallization is performed before the recesses are etched.

MEMS piezoresistive cantilever for the direct measurement of cardiomyocyte contractile force

NASA Astrophysics Data System (ADS)

Matsudaira, Kenei; Nguyen, Thanh-Vinh; Hirayama Shoji, Kayoko; Tsukagoshi, Takuya; Takahata, Tomoyuki; Shimoyama, Isao

2017-10-01

This paper reports on a method to directly measure the contractile forces of cardiomyocytes using MEMS (micro electro mechanical systems)-based force sensors. The fabricated sensor chip consists of piezoresistive cantilevers that can measure contractile forces with high frequency (several tens of kHz) and high sensing resolution (less than 0.1 nN). Moreover, the proposed method does not require a complex observation system or image processing, which are necessary in conventional optical-based methods. This paper describes the design, fabrication, and evaluation of the proposed device and demonstrates the direct measurements of contractile forces of cardiomyocytes using the fabricated device.

Improved Fabrication of Lithium Films Having Micron Features

NASA Technical Reports Server (NTRS)

Whitacre, Jay

2006-01-01

An improved method has been devised for fabricating micron-dimension Li features. This approach is intended for application in the fabrication of lithium-based microelectrochemical devices -- particularly solid-state thin-film lithium microbatteries.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred J; Motala, Michael; Ahn, Jong-Hyun; Park, Sang-Il; Yu, Chang-Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung

2014-05-13

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John [Champaign, IL; Nuzzo, Ralph [Champaign, IL; Meitl, Matthew [Durham, NC; Menard, Etienne [Durham, NC; Baca, Alfred J [Urbana, IL; Motala, Michael [Champaign, IL; Ahn, Jong-Hyun [Suwon, KR; Park, Sang-II [Savoy, IL; Yu,; Chang-Jae, [Urbana, IL; Ko, Heung-Cho [Gwangju, KR; Stoykovich,; Mark, [Dover, NH; Yoon, Jongseung [Urbana, IL

2011-07-05

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred; Motala, Michael; Ahn, Jong -Hyun; Park, Sang -Il; Yu, Chang -Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung

2015-08-25

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Optical systems fabricated by printing-based assembly

DOEpatents

Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred; Motala, Michael; Ahn, Jong-Hyun; Park, Sang-Il; Yu, Chang-Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung

2017-03-21

Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

Investigation of transport properties of coronene.TCNQ cocrystal microrods with coronene microrods and TCNQ microsheets

NASA Astrophysics Data System (ADS)

Wu, Hao-Di; Wang, Feng-Xia; Zhang, Meng; Pan, Ge-Bo

2015-07-01

Coronene.TCNQ cocrystal microrods, coronene microrods, and TCNQ microsheets were constructed by a drop-casting method. Prototype devices were fabricated and their field-effect-transistor (FET) performances were investigated. It is found that coronene.TCNQ microrods had exhibited an n-type characteristic and showed better FET performances than TCNQ microsheets.Coronene.TCNQ cocrystal microrods, coronene microrods, and TCNQ microsheets were constructed by a drop-casting method. Prototype devices were fabricated and their field-effect-transistor (FET) performances were investigated. It is found that coronene.TCNQ microrods had exhibited an n-type characteristic and showed better FET performances than TCNQ microsheets. Electronic supplementary information (ESI) available: Device fabrication and measurements. See DOI: 10.1039/c5nr02778k

One-step direct transfer of pristine single-walled carbon nanotubes for functional nanoelectronics.

PubMed

Wu, Chung Chiang; Liu, Chang Hua; Zhong, Zhaohui

2010-03-10

We report a one-step direct transfer technique for the fabrication of functional nanoelectronic devices using pristine single-walled carbon nanotubes (SWNTs). Suspended SWNTs grown by the chemical vapor deposition (CVD) method are aligned and directly transferred onto prepatterned device electrodes at ambient temperature. Using this technique, we successfully fabricated SWNT electromechanical resonators with gate-tunable resonance frequencies. A fully suspended SWNT p-n diode has also been demonstrated with the diode ideality factor equal to 1. Our method eliminates the organic residues on SWNTs resulting from conventional lithography and solution processing. The results open up opportunities for the fundamental study of electron transport physics in ultraclean SWNTs and for room temperature fabrication of novel functional devices based on pristine SWNTs.

Integrated seal for high-temperature electrochemical device

DOEpatents

Tucker, Michael C; Jacobson, Craig P

2013-07-16

The present invention provides electrochemical device structures having integrated seals, and methods of fabricating them. According to various embodiments the structures include a thin, supported electrolyte film with the electrolyte sealed to the support. The perimeter of the support is self-sealed during fabrication. The perimeter can then be independently sealed to a manifold or other device, e.g., via an external seal. According to various embodiments, the external seal does not contact the electrolyte, thereby eliminating the restrictions on the sealing method and materials imposed by sealing against the electrolyte.

Laser-bulge based ultrasonic bonding method for fabricating multilayer thermoplastic microfluidic devices

NASA Astrophysics Data System (ADS)

Liang, Chao; Liu, Chong; Liu, Ziyang; Meng, Fanjian; Li, Jingmin

2017-11-01

Ultrasonic bonding is a commonly-used method for fabrication of thermoplastic microfluidic devices. However, due to the existence of the energy director (a convex structure to concentrate the ultrasonic energy), it is difficult to control its molten polymer flow, which may result in a small gap between the bonding interface or microchannel clogging. In this paper, we present an approach to address these issues. Firstly, the microchannels were patterned onto the PMMA sheets using hot embossing with the wire electrical discharge machined molds. Then, a small bulge, which was formed at the edge of the laser-ablated groove (LG), was generated around the microchannel using a CO2 laser ablation system. By using the bulge to concentrate the ultrasonic energy, there was no need for fabricating the complicated and customized energy director. When the bulge was melted, it was able to flow into the LG which overcame the ‘gap’ and ‘clogging’ problems. Here, two types of two-layer microfluidic devices and a five-layer micromixer were fabricated to validate its performance. Our results showed that these thermoplastic microdevices can be successfully bonded by using this method. The liquid leakage was not observed in both the capillary-driven flowing test and the pressure-driven mixing experiments. It is a potential method for bonding the thermoplastic microfluidic devices.

Fabrication of Superconducting Quantum Interference Device Magnetometers on a Glass Epoxy Polyimide Resin Substrate with Copper Terminals

NASA Astrophysics Data System (ADS)

Kawai, Jun; Kawabata, Miki; Oyama, Daisuke; Uehara, Gen

We have developed fabrication technique of superconducting quantum interference device (SQUID) magnetometers based on Nb/AlAlOx/Nb junctions directly on a glass epoxy polyimide resin substrate, which has copper terminals embedded in advance. The advantage of this method is that no additional substrate and wirebonds are needed for assembly. Compared to conventional SQUID magnetometers, which are assembled with a SQUID chip fabricated on a Si substrate and wirebonding technique, low risk of disconnection can be expected. A directly-coupled multi-loop SQUID magnetometer fabricated with this method has as good noise performance as a SQUID magnetometer with the same design fabricated on a Si wafer. The magnetometer sustained its performance through thermal cycle test 13 times so far.

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

Nuzzo, Ralph G.; Rogers, John A.; Menard, Etienne

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Disposable photonic integrated circuits for evanescent wave sensors by ultra-high volume roll-to-roll method.

PubMed

Aikio, Sanna; Hiltunen, Jussi; Hiitola-Keinänen, Johanna; Hiltunen, Marianne; Kontturi, Ville; Siitonen, Samuli; Puustinen, Jarkko; Karioja, Pentti

2016-02-08

Flexible photonic integrated circuit technology is an emerging field expanding the usage possibilities of photonics, particularly in sensor applications, by enabling the realization of conformable devices and introduction of new alternative production methods. Here, we demonstrate that disposable polymeric photonic integrated circuit devices can be produced in lengths of hundreds of meters by ultra-high volume roll-to-roll methods on a flexible carrier. Attenuation properties of hundreds of individual devices were measured confirming that waveguides with good and repeatable performance were fabricated. We also demonstrate the applicability of the devices for the evanescent wave sensing of ambient refractive index. The production of integrated photonic devices using ultra-high volume fabrication, in a similar manner as paper is produced, may inherently expand methods of manufacturing low-cost disposable photonic integrated circuits for a wide range of sensor applications.

Systems and Methods for Fabricating Carbon Nanotube-Based Vacuum Electronic Devices

NASA Technical Reports Server (NTRS)

Manohara, Harish (Inventor); Toda, Risaku (Inventor); Del Castillo, Linda Y. (Inventor); Murthy, Rakesh (Inventor)

2015-01-01

Systems and methods in accordance with embodiments of the invention proficiently produce carbon nanotube-based vacuum electronic devices. In one embodiment a method of fabricating a carbon nanotube-based vacuum electronic device includes: growing carbon nanotubes onto a substrate to form a cathode; assembling a stack that includes the cathode, an anode, and a first layer that includes an alignment slot; disposing a microsphere partially into the alignment slot during the assembling of the stack such that the microsphere protrudes from the alignment slot and can thereby separate the first layer from an adjacent layer; and encasing the stack in a vacuum sealed container.

Micro-fabricated integrated coil and magnetic circuit and method of manufacturing thereof

DOEpatents

Mihailovich, Robert E.; Papavasiliou, Alex P.; Mehrotra, Vivek; Stupar, Philip A.; Borwick, III, Robert L.; Ganguli, Rahul; DeNatale, Jeffrey F.

2017-03-28

A micro-fabricated electromagnetic device is provided for on-circuit integration. The electromagnetic device includes a core. The core has a plurality of electrically insulating layers positioned alternatingly between a plurality of magnetic layers to collectively form a continuous laminate having alternating magnetic and electrically insulating layers. The electromagnetic device includes a coil embedded in openings of the semiconductor substrate. An insulating material is positioned in the cavity and between the coil and an inner surface of the core. A method of manufacturing the electromagnetic device includes providing a semiconductor substrate having openings formed therein. Windings of a coil are electroplated and embedded in the openings. The insulating material is coated on or around an exposed surface of the coil. Alternating magnetic layers and electrically insulating layers may be micro-fabricated and electroplated as a single and substantially continuous segment on or around the insulating material.

One-step direct-laser metal writing of sub-100 nm 3D silver nanostructures in a gelatin matrix

NASA Astrophysics Data System (ADS)

Kang, SeungYeon; Vora, Kevin; Mazur, Eric

2015-03-01

Developing an ability to fabricate high-resolution, 3D metal nanostructures in a stretchable 3D matrix is a critical step to realizing novel optoelectronic devices such as tunable bulk metal-dielectric optical devices and THz metamaterial devices that are not feasible with alternative techniques. We report a new chemistry method to fabricate high-resolution, 3D silver nanostructures using a femtosecond-laser direct metal writing technique. Previously, only fabrication of 3D polymeric structures or single-/few-layer metal structures was possible. Our method takes advantage of unique gelatin properties to overcome such previous limitations as limited freedom in 3D material design and short sample lifetime. We fabricate more than 15 layers of 3D silver nanostructures with a resolution of less than 100 nm in a stable dielectric matrix that is flexible and has high large transparency that is well-matched for potential applications in the optical and THz metamaterial regimes. This is a single-step process that does not require any further processing. This work will be of interest to those interested in fabrication methods that utilize nonlinear light-matter interactions and the realization of future metamaterials.

Fabrication and Evaluation of Microfluidic Immunoassay Devices with Antibody-Immobilized Microbeads Retained in Porous Hydrogel Micropillars.

PubMed

Kasama, Toshihiro; Kaji, Noritada; Tokeshi, Manabu; Baba, Yoshinobu

2017-01-01

Due to the inherent characteristics including confinement of molecular diffusion and high surface-to-volume ratio, microfluidic device-based immunoassay has great advantages in cost, speed, sensitivity, and so on, compared with conventional techniques such as microtiter plate-based ELISA, latex agglutination method, and lateral flow immunochromatography. In this paper, we explain the detection of C-reactive protein as a model antigen by using our microfluidic immunoassay device, so-called immuno-pillar device. We describe in detail how we fabricated and used the immuno-pillar devices.

A High-yield Two-step Transfer Printing Method for Large-scale Fabrication of Organic Single-crystal Devices on Arbitrary Substrates

PubMed Central

Deng, Wei; Zhang, Xiujuan; Pan, Huanhuan; Shang, Qixun; Wang, Jincheng; Zhang, Xiaohong; Zhang, Xiwei; Jie, Jiansheng

2014-01-01

Single-crystal organic nanostructures show promising applications in flexible and stretchable electronics, while their applications are impeded by the large incompatibility with the well-developed photolithography techniques. Here we report a novel two-step transfer printing (TTP) method for the construction of organic nanowires (NWs) based devices onto arbitrary substrates. Copper phthalocyanine (CuPc) NWs are first transfer-printed from the growth substrate to the desired receiver substrate by contact-printing (CP) method, and then electrode arrays are transfer-printed onto the resulting receiver substrate by etching-assisted transfer printing (ETP) method. By utilizing a thin copper (Cu) layer as sacrificial layer, microelectrodes fabricated on it via photolithography could be readily transferred to diverse conventional or non-conventional substrates that are not easily accessible before with a high transfer yield of near 100%. The ETP method also exhibits an extremely high flexibility; various electrodes such as Au, Ti, and Al etc. can be transferred, and almost all types of organic devices, such as resistors, Schottky diodes, and field-effect transistors (FETs), can be constructed on planar or complex curvilinear substrates. Significantly, these devices can function properly and exhibit closed or even superior performance than the device counterparts fabricated by conventional approach. PMID:24942458

Fully Printable Organic and Perovskite Solar Cells with Transfer-Printed Flexible Electrodes.

PubMed

Li, Xianqiang; Tang, Xiaohong; Ye, Tao; Wu, Dan; Wang, Hong; Wang, Xizu

2017-06-07

The perovskite solar cells (PSCs) and organic solar cells (OSCs) with high performance were fabricated with transfer-printed top metal electrodes. We have demonstrated that PSCs and OSCs with the top Au electrodes fabricated by using the transfer printing method have comparable or better performance than the devices with the top Au electrodes fabricated by using the conventional thermal evaporation method. The highest PCE of the PSCs and OSCs with the top electrodes fabricated using the transfer printing method achieved 13.72% and 2.35%, respectively. It has been investigated that fewer defects between the organic thin films and Au electrodes exist by using the transfer printing method which improved the device stability. After storing the PSCs and OSCs with the transfer-printed electrodes in a nitrogen environment for 97 and 103 days without encapsulation, the PSCs and OSCs still retained 71% and 91% of their original PCEs, respectively.

Whatever happened to silicon carbide. [semiconductor devices

NASA Technical Reports Server (NTRS)

Campbell, R. B.

1981-01-01

The progress made in silicon carbide semiconductor devices in the 1955 to 1975 time frame is examined and reasons are given for the present lack of interest in the material. Its physical and chemical properties and methods of preparation are discussed. Fabrication techniques and the characteristics of silicon carbide devices are reviewed. It is concluded that a combination of economic factors and the lack of progress in fabrication techniques leaves no viable market for SiC devices in the near future.

Boundary conditioning of capacitive MEMS devices through fabrication methods and operating environments

NASA Astrophysics Data System (ADS)

Muthukumaran, Packirisamy; Stiharu, Ion G.; Bhat, Rama B.

2003-10-01

This paper presents and applies the concept of micro-boundary conditioning to the design synthesis of microsystems in order to quantify the influence of inherent limitations of the fabrication process and the operating conditions on both static and dynamic behavior of microsystems. The predicted results on the static and dynamic behavior of a capacitive MEMS device, fabricated through MUMPs process, under the influence of the fabrication limitation and operating environment are presented along with the test results. The comparison between the predicted and experimental results shows a good agreement.

Electrical device fabrication from nanotube formations

DOEpatents

Nicholas, Nolan Walker; Kittrell, W. Carter; Kim, Myung Jong; Schmidt, Howard K.

2013-03-12

A method for forming nanotube electrical devices, arrays of nanotube electrical devices, and device structures and arrays of device structures formed by the methods. Various methods of the present invention allow creation of semiconducting and/or conducting devices from readily grown SWNT carpets rather than requiring the preparation of a patterned growth channel and takes advantage of the self-controlling nature of these carpet heights to ensure a known and controlled channel length for reliable electronic properties as compared to the prior methods.

Emerging Trends in Phosphorene Fabrication towards Next Generation Devices

PubMed Central

Dhanabalan, Sathish Chander; Ponraj, Joice Sophia; Guo, Zhinan

2017-01-01

The challenge of science and technology is to design and make materials that will dominate the future of our society. In this context, black phosphorus has emerged as a new, intriguing two‐dimensional (2D) material, together with its monolayer, which is referred to as phosphorene. The exploration of this new 2D material demands various fabrication methods to achieve potential applications— this demand motivated this review. This article is aimed at supplementing the concrete understanding of existing phosphorene fabrication techniques, which forms the foundation for a variety of applications. Here, the major issue of the degradation encountered in realizing devices based on few‐layered black phosphorus and phosphorene is reviewed. The prospects of phosphorene in future research are also described by discussing its significance and explaining ways to advance state‐of‐art of phosphorene‐based devices. In addition, a detailed presentation on the demand for future studies to promote well‐systemized fabrication methods towards large‐area, high‐yield and perfectly protected phosphorene for the development of reliable devices in optoelectronic applications and other areas is offered. PMID:28638779

Effect of post-annealing on sputtered MoS2 films

NASA Astrophysics Data System (ADS)

Wong, W. C.; Ng, S. M.; Wong, H. F.; Cheng, W. F.; Mak, C. L.; Leung, C. W.

2017-12-01

Typical routes for fabricating MoS2-based electronic devices rely on the transfer of as-prepared flakes to target substrates, which is incompatible with conventional device fabrication methods. In this work we investigated the preparation of MoS2 films by magnetron sputtering. By subjecting room-temperature sputtered MoS2 films to post-annealing at mild conditions (450 °C in a nitrogen flow), crystalline MoS2 films were formed. To demonstrate the compatibility of the technique with typical device fabrication processes, MoS2 was prepared on epitaxial magnetic oxide films of La0.7Sr0.3MnO3, and the magnetic behavior of the films were unaffected by the post-annealing process. This work demonstrates the possibility of fabricating electronic and spintronic devices based on continuous MoS2 films prepared by sputtering deposition.

Review Article: Progress in fabrication of transition metal dichalcogenides heterostructure systems

PubMed Central

Dong, Rui; Kuljanishvili, Irma

2017-01-01

Transition metal dichalcogenide (TMDC) semiconductors have attracted significant attention because of their rich electronic/photonic properties and importance for fundamental research and novel device applications. These materials provide a unique opportunity to build up high quality and atomically sharp heterostructures because of the nature of weak van der Waals interlayer interactions. The variable electronic properties of TMDCs (e.g., band gap and their alignment) provide a platform for the design of novel electronic and optoelectronic devices. The integration of TMDC heterostructures into the semiconductor industry is presently hindered by limited options in reliable production methods. Many exciting properties and device architectures which have been studied to date are, in large, based on the exfoliation methods of bulk TMDC crystals. These methods are generally more difficult to consider for large scale integration processes, and hence, continued developments of different fabrication strategies are essential for further advancements in this area. In this review, the authors highlight the recent progress in the fabrication of TMDC heterostructures. The authors will review several methods most commonly used to date for controllable heterostructure formation. One of the focuses will be on TMDC heterostructures fabricated by thermal chemical vapor deposition methods which allow for the control over the resulting materials, individual layers and heterostructures. Another focus would be on the techniques for selective growth of TMDCs. The authors will discuss conventional and unconventional fabrication methods and their advantages and drawbacks and will provide some guidance for future improvements. Mask-assisted and mask-free methods will be presented, which include traditional lithographic techniques (photo- or e-beam lithography) and some unconventional methods such as the focus ion beam and the recently developed direct-write patterning approach, which are shown to be promising for the fabrication of quality TMDC heterostructures. PMID:29075580

Versatile fabrication of paper-based microfluidic devices with high chemical resistance using scholar glue and magnetic masks.

PubMed

Cardoso, Thiago M G; de Souza, Fabrício R; Garcia, Paulo T; Rabelo, Denilson; Henry, Charles S; Coltro, Wendell K T

2017-06-29

Simple methods have been developed for fabricating microfluidic paper-based analytical devices (μPADs) but few of these devices can be used with organic solvents and/or aqueous solutions containing surfactants. This study describes a simple fabrication strategy for μPADs that uses readily available scholar glue to create the hydrophobic flow barriers that are resistant to surfactants and organic solvents. Microfluidic structures were defined by magnetic masks designed with either neodymium magnets or magnetic sheets to define the patter, and structures were created by spraying an aqueous solution of glue on the paper surface. The glue-coated paper was then exposed to UV/Vis light for cross-linking to maximize chemical resistance. Examples of microzone arrays and microfluidic devices are demonstrated. μPADs fabricated with scholar glue retained their barriers when used with surfactants, organic solvents, and strong/weak acids and bases unlike common wax-printed barriers. Paper microzones and microfluidic devices were successfully used for colorimetric assays of clinically relevant analytes commonly detected in urinalysis to demonstrate the low background of the barrier material and generally applicability to sensing. The proposed fabrication method is attractive for both its ability to be used with diverse chemistries and the low cost and simplicity of the materials and process. Copyright © 2017 Elsevier B.V. All rights reserved.

Epoxy bond and stop etch fabrication method

DOEpatents

Simmons, Jerry A.; Weckwerth, Mark V.; Baca, Wes E.

2000-01-01

A class of epoxy bond and stop etch (EBASE) microelectronic fabrication techniques is disclosed. The essence of such techniques is to grow circuit components on top of a stop etch layer grown on a first substrate. The first substrate and a host substrate are then bonded together so that the circuit components are attached to the host substrate by the bonding agent. The first substrate is then removed, e.g., by a chemical or physical etching process to which the stop etch layer is resistant. EBASE fabrication methods allow access to regions of a device structure which are usually blocked by the presence of a substrate, and are of particular utility in the fabrication of ultrafast electronic and optoelectronic devices and circuits.

Biomedical microfluidic devices by using low-cost fabrication techniques: A review.

PubMed

Faustino, Vera; Catarino, Susana O; Lima, Rui; Minas, Graça

2016-07-26

One of the most popular methods to fabricate biomedical microfluidic devices is by using a soft-lithography technique. However, the fabrication of the moulds to produce microfluidic devices, such as SU-8 moulds, usually requires a cleanroom environment that can be quite costly. Therefore, many efforts have been made to develop low-cost alternatives for the fabrication of microstructures, avoiding the use of cleanroom facilities. Recently, low-cost techniques without cleanroom facilities that feature aspect ratios more than 20, for fabricating those SU-8 moulds have been gaining popularity among biomedical research community. In those techniques, Ultraviolet (UV) exposure equipment, commonly used in the Printed Circuit Board (PCB) industry, replaces the more expensive and less available Mask Aligner that has been used in the last 15 years for SU-8 patterning. Alternatively, non-lithographic low-cost techniques, due to their ability for large-scale production, have increased the interest of the industrial and research community to develop simple, rapid and low-cost microfluidic structures. These alternative techniques include Print and Peel methods (PAP), laserjet, solid ink, cutting plotters or micromilling, that use equipment available in almost all laboratories and offices. An example is the xurography technique that uses a cutting plotter machine and adhesive vinyl films to generate the master moulds to fabricate microfluidic channels. In this review, we present a selection of the most recent lithographic and non-lithographic low-cost techniques to fabricate microfluidic structures, focused on the features and limitations of each technique. Only microfabrication methods that do not require the use of cleanrooms are considered. Additionally, potential applications of these microfluidic devices in biomedical engineering are presented with some illustrative examples. Copyright © 2015 Elsevier Ltd. All rights reserved.

Three-dimensional wax patterning of paper fluidic devices.

PubMed

Renault, Christophe; Koehne, Jessica; Ricco, Antonio J; Crooks, Richard M

2014-06-17

In this paper we describe a method for three-dimensional wax patterning of microfluidic paper-based analytical devices (μPADs). The method is rooted in the fundamental details of wax transport in paper and provides a simple way to fabricate complex channel architectures such as hemichannels and fully enclosed channels. We show that three-dimensional μPADs can be fabricated with half as much paper by using hemichannels rather than ordinary open channels. We also provide evidence that fully enclosed channels are efficiently isolated from the exterior environment, decreasing contamination risks, simplifying the handling of the device, and slowing evaporation of solvents.

Melt-and-mold fabrication (MnM-Fab) of reconfigurable low-cost devices for use in resource-limited settings.

PubMed

Li, Zhi; Tevis, Ian D; Oyola-Reynoso, Stephanie; Newcomb, Lucas B; Halbertsma-Black, Julian; Bloch, Jean-Francis; Thuo, Martin

2015-12-01

Interest in low-cost analytical devices (especially for diagnostics) has recently increased; however, concomitant translation to the field has been slow, in part due to personnel and supply-chain challenges in resource-limited settings. Overcoming some of these challenges require the development of a method that takes advantage of locally available resources and/or skills. We report a Melt-and-mold fabrication (MnM Fab) approach to low-cost and simple devices that has the potential to be adapted locally since it requires a single material that is recyclable and simple skills to access multiple devices. We demonstrated this potential by fabricating entry level bio-analytical devices using an affordable low-melting metal alloy, Field's metal, with molds produced from known materials such as plastic (acrylonitrile-butadiene-styrene (ABS)), glass, and paper. We fabricated optical gratings then 4×4 well plates using the same recycled piece of metal. We then reconfigured the well plates into rapid prototype microfluidic devices with which we demonstrated laminar flow, droplet generation, and bubble formation from T-shaped channels. We conclude that this MnM-Fab method is capable of addressing some challenges typically encountered with device translation, such as technical know-how or material supply, and that it can be applied to other devices, as needed in the field, using a single moldable material. Copyright © 2015 Elsevier B.V. All rights reserved.

Rapid and inexpensive fabrication of polymeric microfluidic devices via toner transfer masking

PubMed Central

Easley, Christopher J.; Benninger, Richard K. P.; Shaver, Jesse H.; Head, W. Steven; Piston, David W.

2009-01-01

Summary An alternative fabrication method is presented for production of masters for single- or multilayer polymeric microfluidic devices in a standard laboratory environment, precluding the need for a cleanroom. This toner transfer masking (TTM) method utilizes an office laser printer to generate a toner pattern which is thermally transferred to a metal master to serve as a mask for etching. With master fabrication times as little as one hour (depending on channel depth) using commercially-available equipment and supplies, this approach should make microfluidic technology more widely accessible to the non-expert—even the non-scientist. The cost of fabrication consumables was estimated to be < $1 per master, over an order of magnitude decrease in consumable costs compared to standard photolithography. In addition, the use of chemical etching allows accurate control over the height of raised features (i.e., channel depths), allowing the flexibility to fabricate multiple depths on a single master with little added time. Resultant devices are shown capable of pneumatic valving, three-dimensional channel formation (using layer-connecting vias), droplet fluidics, and cell imaging and staining. The multiple-depth capabilities of the method are proven useful for cellular analysis by fabrication of handheld, disposable devices used for trapping and imaging of live murine pancreatic islets. The precise fluidic control provided by the microfluidic platform allows subsequent fixing and staining of these cells without significant movement, thus spatial correlation of imaging and staining is attainable—even with rare alpha cells that constitute only ∼10% of the islet cells. PMID:19350094

The Fabrication of Nanoimprinted P3HT Nanograting by Patterned ETFE Mold at Room Temperature and Its Application for Solar Cell

NASA Astrophysics Data System (ADS)

Ding, Guangzhu; Wang, Kaixuan; Li, Xiaohui; Chen, Qing; Hu, Zhijun; Liu, Jieping

2016-05-01

Nanoimprinting lithography (NIL) is investigated as a promising method to define nanostructure; however, finding a practical method to achieve large area patterning of conjugated polymer remains a challenge. We demonstrate here that a simple and cost-effective technique is proposed to fabricate the nanoimprinted P3HT nanograting by solvent-assisted room temperature NIL (SART-NIL) method with patterned ETFE film as mold. The patterned ETFE template is produced by embossing ETFE film into a patterned silicon master and is used as template to transfer nanogratings during the SART-NIL process. It indicates that highly reproducible and well-controlled P3HT nanograting film is obtained successfully with feature size of nanogratings ranging from 130 to 700 nm, due to the flexibility, stiffness, and low surface energy of ETFE mold. Moreover, the SART-NIL method using ETFE mold is able to fabricate nanogratings but not to induce the change of molecular orientation within conjugated polymer. The conducting ability of P3HT nanograting in the vertical direction is also not damaged after patterning. Finally, we further apply P3HT nanograting for the fabrication of active layer of OBHJ solar cell device, to investigate the morphology role presented by ETFE mold in device performance. The device performance of OBHJ solar cell is preferential to that of PBHJ device obviously.

The Fabrication of Nanoimprinted P3HT Nanograting by Patterned ETFE Mold at Room Temperature and Its Application for Solar Cell.

PubMed

Ding, Guangzhu; Wang, Kaixuan; Li, Xiaohui; Chen, Qing; Hu, Zhijun; Liu, Jieping

2016-12-01

Nanoimprinting lithography (NIL) is investigated as a promising method to define nanostructure; however, finding a practical method to achieve large area patterning of conjugated polymer remains a challenge. We demonstrate here that a simple and cost-effective technique is proposed to fabricate the nanoimprinted P3HT nanograting by solvent-assisted room temperature NIL (SART-NIL) method with patterned ETFE film as mold. The patterned ETFE template is produced by embossing ETFE film into a patterned silicon master and is used as template to transfer nanogratings during the SART-NIL process. It indicates that highly reproducible and well-controlled P3HT nanograting film is obtained successfully with feature size of nanogratings ranging from 130 to 700 nm, due to the flexibility, stiffness, and low surface energy of ETFE mold. Moreover, the SART-NIL method using ETFE mold is able to fabricate nanogratings but not to induce the change of molecular orientation within conjugated polymer. The conducting ability of P3HT nanograting in the vertical direction is also not damaged after patterning. Finally, we further apply P3HT nanograting for the fabrication of active layer of OBHJ solar cell device, to investigate the morphology role presented by ETFE mold in device performance. The device performance of OBHJ solar cell is preferential to that of PBHJ device obviously.

Method and apparatus for fluid dispersion

DOEpatents

Stone, Howard A.; Anna, Shelley L.; Bontoux, Nathalie; Link, Darren Roy; Weitz, David A.; Gitlin, Irina; Kumacheva, Eugenia; Garstecki, Piotr; Diluzio, Willow R.; Whitesides, George M.

2012-12-25

A microfluidic method and device for focusing and/or forming discontinuous sections of similar or dissimilar size in a fluid is provided. The device can be fabricated simply from readily-available, inexpensive material using simple techniques.

Method and apparatus for fluid dispersion

DOEpatents

Stone, Howard A; Anna, Shelley L; Bontoux, Nathalie; Link, Darren Roy; Weitz, David A; Gitlin, Irina; Kumacheva, Eugenia; Garstecki, Piotr; Diluzio, Willow R; Whitesides, George M

2015-03-24

A microfluidic method and device for focusing and/or forming discontinuous sections of similar or dissimilar size in a fluid is provided. The device can be fabricated simply from readily-available, inexpensive material using simple techniques.

Method and apparatus for fluid dispersion

DOEpatents

Stone, Howard A.; Anna, Shelley L.; Bontoux, Nathalie; Link, Darren R.; Weitz, David A.; Gitlin, Irina; Kumacheva, Eugenia; Garstecki, Piotr; Diluzio, Willow; Whitesides, George M.

2010-05-04

A microfluidic method and device for focusing and/or forming discontinuous sections of similar or dissimilar size in a fluid is provided. The device can be fabricated simply from readily-available, inexpensive material using simple techniques.

MEMS/ECD Method for Making Bi(2-x)Sb(x)Te3 Thermoelectric Devices

NASA Technical Reports Server (NTRS)

Lim, James; Huang, Chen-Kuo; Ryan, Margaret; Snyder, G. Jeffrey; Herman, Jennifer; Fleurial, Jean-Pierre

2008-01-01

A method of fabricating Bi(2-x)Sb(x)Te3-based thermoelectric microdevices involves a combination of (1) techniques used previously in the fabrication of integrated circuits and of microelectromechanical systems (MEMS) and (2) a relatively inexpensive MEMS-oriented electrochemical-deposition (ECD) technique. The present method overcomes the limitations of prior MEMS fabrication techniques and makes it possible to satisfy requirements.

Controlling Kink Geometry in Nanowires Fabricated by Alternating Metal-Assisted Chemical Etching.

PubMed

Chen, Yun; Li, Liyi; Zhang, Cheng; Tuan, Chia-Chi; Chen, Xin; Gao, Jian; Wong, Ching-Ping

2017-02-08

Kinked silicon (Si) nanowires (NWs) have many special properties that make them attractive for a number of applications, such as microfluidics devices, microelectronic devices, and biosensors. However, fabricating NWs with controlled three-dimensional (3D) geometry has been challenging. In this work, a novel method called alternating metal-assisted chemical etching is reported for the fabrication of kinked Si NWs with controlled 3D geometry. By the use of multiple etchants with carefully selected composition, one can control the number of kinks, their locations, and their angles by controlling the number of etchant alternations and the time in each etchant. The resulting number of kinks equals the number times the etchant is alternated, the length of each segment separated by kinks has a linear relationship with the etching time, and the kinking angle is related to the surface tension and viscosity of the etchants. This facile method may provide a feasible and economical way to fabricate novel silicon nanowires, nanostructures, and devices for broad applications.

Solution processed flexible organic thin film back-gated transistors based on polyimide dielectric films

NASA Astrophysics Data System (ADS)

Park, Janghoon; Min, Yoonki; Lee, Dongjin

2018-04-01

An organic thin film back-gated transistor (OBGT) was fabricated and characterized. The gate electrode was printed on the back side of substrate, and the dielectric layer was omitted by substituting the dielectric layer with the polyimide (PI) film substrate. Roll-to-roll (R2R) gravure printing, doctor blading, and drop casting methods were used to fabricate the OBGT. The printed OBGT device shows better performance compared with an OTFT device based on dielectric layer of BaTiO3. Additionally, a calendering process enhanced the performance by a factor of 3 to 7 (mobility: 0.016 cm2/V.s, on/off ratio: 9.17×103). A bending test was conducted to confirm the flexibility and durability of the OBGT device. The results show the fabricated device endures 20000-cyclic motions. The realized OBGT device was successfully fabricated and working, which is meaningful for production engineering from the viewpoint of process development.

Laser direct writing of micro- and nano-scale medical devices

PubMed Central

Gittard, Shaun D; Narayan, Roger J

2010-01-01

Laser-based direct writing of materials has undergone significant development in recent years. The ability to modify a variety of materials at small length scales and using short production times provides laser direct writing with unique capabilities for fabrication of medical devices. In many laser-based rapid prototyping methods, microscale and submicroscale structuring of materials is controlled by computer-generated models. Various laser-based direct write methods, including selective laser sintering/melting, laser machining, matrix-assisted pulsed-laser evaporation direct write, stereolithography and two-photon polymerization, are described. Their use in fabrication of microstructured and nanostructured medical devices is discussed. Laser direct writing may be used for processing a wide variety of advanced medical devices, including patient-specific prostheses, drug delivery devices, biosensors, stents and tissue-engineering scaffolds. PMID:20420557

Insertion of lithium into electrochromic devices after completion

DOEpatents

Berland, Brian Spencer; Lanning, Bruce Roy; Frey, Jonathan Mack; Barrett, Kathryn Suzanne; DuPont, Paul Damon; Schaller, Ronald William

2015-12-22

The present disclosure describes methods of inserting lithium into an electrochromic device after completion. In the disclosed methods, an ideal amount of lithium can be added post-fabrication to maximize or tailor the free lithium ion density of a layer or the coloration range of a device. Embodiments are directed towards a method to insert lithium into the main device layers of an electrochromic device as a post-processing step after the device has been manufactured. In an embodiment, the methods described are designed to maximize the coloration range while compensating for blind charge loss.

Micromilling: A method for ultra-rapid prototyping of plastic microfluidic devices

PubMed Central

Guckenberger, David J.; de Groot, Theodorus E.; Wan, Alwin M.D.; Beebe, David J.; Young, Edmond W. K.

2015-01-01

This tutorial review offers protocols, tips, insight, and considerations for practitioners interested in using micromilling to create microfluidic devices. The objective is to provide a potential user with information to guide them on whether micromilling would fill a specific need within their overall fabrication strategy. Comparisons are made between micromilling and other common fabrication methods for plastics in terms of technical capabilities and cost. The main discussion focuses on “how-to” aspects of micromilling, to enable a user to select proper equipment and tools, and obtain usable microfluidic parts with minimal start-up time and effort. The supplementary information provides more extensive discussion on CNC mill setup, alignment, and programming. We aim to reach an audience with minimal prior experience in milling, but with strong interests in fabrication of microfluidic devices. PMID:25906246

Laser-assisted fabrication of single-layer flexible touch sensor

PubMed Central

Son, Seokwoo; Park, Jong Eun; Lee, Joohyung; Yang, Minyang; Kang, Bongchul

2016-01-01

Single-layer flexible touch sensor that is designed for the indium-tin-oxide (ITO)-free, bendable, durable, multi-sensible, and single layer transparent touch sensor was developed via a low-cost and one-step laser-induced fabrication technology. To this end, an entirely novel approach involving material, device structure, and even fabrication method was adopted. Conventional metal oxides based multilayer touch structure was substituted by the single layer structure composed of integrated silver wire networks of sensors and bezel interconnections. This structure is concurrently fabricated on a glass substitutive plastic film via the laser-induced fabrication method using the low-cost organometallic/nanoparticle hybrid complex. In addition, this study addresses practical solutions to heterochromia and interference problem with a color display unit. As a result, a practical touch sensor is successfully demonstrated through resolving the heterochromia and interference problems with color display unit. This study could provide the breakthrough for early realization of wearable device. PMID:27703204

High density pixel array and laser micro-milling method for fabricating array

NASA Technical Reports Server (NTRS)

McFall, James Earl (Inventor); Wiener-Avnear, Eliezer (Inventor)

2003-01-01

A pixel array device is fabricated by a laser micro-milling method under strict process control conditions. The device has an array of pixels bonded together with an adhesive filling the grooves between adjacent pixels. The array is fabricated by moving a substrate relative to a laser beam of predetermined intensity at a controlled, constant velocity along a predetermined path defining a set of grooves between adjacent pixels so that a predetermined laser flux per unit area is applied to the material, and repeating the movement for a plurality of passes of the laser beam until the grooves are ablated to a desired depth. The substrate is of an ultrasonic transducer material in one example for fabrication of a 2D ultrasonic phase array transducer. A substrate of phosphor material is used to fabricate an X-ray focal plane array detector.

Chemical free device fabrication of two dimensional van der Waals materials based transistors by using one-off stamping

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

Lee, Young Tack, E-mail: 023273@kist.re.kr, E-mail: stunalren@gmail.com; Choi, Won Kook; Materials and Life Science Research Division, Korea Institute of Science and Technology

We report on a chemical free one-off imprinting method to fabricate two dimensional (2D) van der Waals (vdWs) materials based transistors. Such one-off imprinting technique is the simplest and effective way to prevent unintentional chemical reaction or damage of 2D vdWs active channel during device fabrication process. 2D MoS{sub 2} nanosheets based transistors with a hexagonal-boron-nitride (h-BN) passivation layer, prepared by one-off imprinting, show negligible variations of transfer characteristics after chemical vapor deposition process. In addition, this method enables the fabrication of all 2D MoS{sub 2} transistors consisting of h-BN gate insulator, and graphene source/drain and gate electrodes without anymore » chemical damage.« less

Fabrication of solar beam steering electrowetting devices—present status and future prospects

NASA Astrophysics Data System (ADS)

Khan, I.; Castelletto, S.; Rosengarten, G.

2017-10-01

Many different technologies are used to track the movement of the sun to both enable concentration of its energy and maximize the yearly energy capture. Their present main limitations are the cost, size, visual impact and wind loading, particularly for applications involving mounting to a building. A parabolic concentrator, for example, along with its steering equipment is heavy and bulky, and is not suitable for rooftop applications. Instead, thin and flat solar concentration devices are required for hassle-free rooftop applications. The use of electrowetting-controlled liquid lenses has emerged as a novel approach for solar tracking and concentration. By steering sunlight using thin electrowetting cell arrays, bulky mechanical equipment is not required. The basic concept of this technology is to change the shape of a liquid interface that is formed by two immiscible fluids of different refractive indices, by simply applying an electric field. An important challenge in electrowetting beam steering devices is the optimization of the design and fabrication process for each of their main constituent components, to maximize optical efficiency. In this paper, we report on the state-of-the-art fabrication methods for electrowetting devices for solar beam steering. We have reviewed the present status of different components types and related fabrication methods, and how they affect the efficiency and performance of such devices. The work identifies future prospects in using electrowetting beam steering devices for solar energy applications. This paper will help researchers and developers in the field to determine the components and fabrication process that affect the development of efficient beam steering electrowetting devices.

Microfabricated plastic chips by hot embossing methods and their applications for DNA separation and detection

NASA Astrophysics Data System (ADS)

Lee, Gwo-Bin; Chen, Shu-Hui; Huang, Guan-Ruey; Lin, Yen-Heng; Sung, Wang-Chou

2000-08-01

Design and fabrication of microfluidic devices on polymethylmethacrylate (PMMA) substrates using novel microfabrication methods are described. The image of microfluidic devices is transferred from quartz master templates possessing inverse image of the devices to plastic plates by using hot embossing method. The micro channels on master templates are formed by the combination of metal etch mask and wet chemical etching. The micromachined quartz templates can be used repeatedly to fabricate cheap and disposable plastic devices. The reproducibility of the hot embossing method is evaluated after using 10 channels on different plastics. The relative standard deviation of the plastic channel profile from ones on quartz templates is less than 1%. In this study, the PMMA chips have been demonstrated as a micro capillary electrophoresis ((mu) -CE) device for DNA separation and detection. The capability of the fabricated chip for electrophoretic injection and separation is characterized via the analysis of DNA fragments (phi) X174. Results indicate that all of the 11 DNA fragments of the size marker could be identified in less than 3 minutes with relative standard deviations less than 0.4% and 8% for migration time and peak area, respectively. Moreover, with the use of near IR dye, fluorescence signals of the higher molecular weight fragments ($GTR 603 bp in length) could be detected at total DNA concentrations as low as 0.1 (mu) g/mL. In addition to DNA fragments (phi) X174, DNA sizing of hepatitis C viral (HCV) amplicon is also achieved using microchip electrophoresis fabricated on PMMA substrate.

Fabrication technology of CNT-Nickel Oxide based planar pseudocapacitor for MEMS and NEMS

NASA Astrophysics Data System (ADS)

Lebedev, E. A.; Kitsyuk, E. P.; Gavrilin, I. M.; Gromov, D. G.; Gruzdev, N. E.; Gavrilov, S. A.; Dronov, A. A.; Pavlov, A. A.

2015-11-01

Fabrication technology of planar pseudocapacitor (PsC) based on carbon nanotube (CNT) forest, synthesized using plasma enhanced chemical vapor deposition (PECVD) method, covered with thin nickel oxide layer deposited by successive ionic layer adsorption and reaction (SILAR) method, is demonstrated. Dependences of deposited oxide layers thickness on device specific capacities is studied. It is shown that pseudocapacity of nickel oxide thin layer increases specific capacity of the CNT's based device up to 2.5 times.

TH-CD-201-12: Preliminary Evaluation of Organic Field Effect Transistors as Radiation Detectors

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

Syme, A; Lin, H; Rubio-Sanchez, J

Purpose: To fabricate organic field effect transistors (OFETs) and evaluate their performance before and after exposure to ionizing radiation. To determine if OFETs have potential to function as radiation dosimeters. Methods: OFETs were fabricated on both Si/SiO{sub 2} wafers and flexible polymer substrates using standard processing techniques. Pentacene was used as the organic semiconductor material and the devices were fabricated in a bottom gate configuration. Devices were irradiated using an orthovoltage treatment unit (120 kVp x-rays). Threshold voltage values were measured with the devices in saturation mode and quantified as a function of cumulative dose. Current-voltage characteristics of the devicesmore » were measured using a Keithley 2614 SourceMeter SMU Instrument. The devices were connected to the reader but unpowered during irradiations. Results: Devices fabricated on Si/SiO2 wafers demonstrated excellent linearity (R{sup 2} > 0.997) with threshold voltages that ranged between 15 and 36 V. Devices fabricated on a flexible polymer substrate had substantially smaller threshold voltages (∼ 4 – 8 V) and slightly worse linearity (R{sup 2} > 0.98). The devices demonstrated excellent stability in I–V characteristics over a large number (>2000) cycles. Conclusion: OFETs have demonstrated excellent potential in radiation dosimetry applications. A key advantage of these devices is their composition, which can be substantially more tissue-equivalent at low photon energies relative to many other types of radiation detector. In addition, fabrication of organic electronics can employ techniques that are faster, simpler and cheaper than conventional silicon-based devices. These results support further development of organic electronic devices for radiation detection purposes. Funding Support, Disclosures, and Conflict of Interest: This work was funded by the Natural Sciences and Engineering Research Council of Canada.« less

Direct growth of graphene-dielectric bi-layer structure on device substrates from Si-based polymer

NASA Astrophysics Data System (ADS)

Seo, Hong-Kyu; Kim, Kyunghun; Min, Sung-Yong; Lee, Yeongjun; Eon Park, Chan; Raj, Rishi; Lee, Tae-Woo

2017-06-01

To facilitate the utilization of graphene films in conventional semiconducting devices (e.g. transistors and memories) which includes an insulating layer such as gate dielectric, facile synthesis of bi-layers composed of a graphene film and an insulating layer by one-step thermal conversion will be very important. We demonstrate a simple, inexpensive, scalable and patternable process to synthesize graphene-dielectric bi-layer films from solution-processed polydimethylsiloxane (PDMS) under a Ni capping layer. This method fabricates graphene-dielectric bi-layer structure simultaneously directly on substrate by thermal conversion of PDMS without using additional graphene transfer and patterning process or formation of an expensive dielectric layer, which makes the device fabrication process much easier. The graphene-dielectric bi-layer on a conducting substrate was used in bottom-contact pentacene field-effect transistors that showed ohmic contact and small hysteresis. Our new method will provide a way to fabricate flexible electronic devices simply and inexpensively.

A Study of Dip-Coatable, High-Capacitance Ion Gel Dielectrics for 3D EWOD Device Fabrication

PubMed Central

Clement, Carlos E.; Jiang, Dongyue; Thio, Si Kuan; Park, Sung-Yong

2017-01-01

We present a dip-coatable, high-capacitance ion gel dielectric for scalable fabrication of three-dimensional (3D) electrowetting-on-dielectric (EWOD) devices such as an n × n liquid prism array. Due to the formation of a nanometer-thick electric double layer (EDL) capacitor, an ion gel dielectric offers two to three orders higher specific capacitance (c ≈ 10 μF/cm2) than that of conventional dielectrics such as SiO2. However, the previous spin-coating method used for gel layer deposition poses several issues for 3D EWOD device fabrication, particularly when assembling multiple modules. Not only does the spin-coating process require multiple repetitions per module, but the ion gel layer also comes in risks of damage or contamination due to handling errors caused during assembly. In addition, it was observed that the chemical formulation previously used for the spin-coating method causes the surface defects on the dip-coated gel layers and thus leads to poor EWOD performance. In this paper, we alternatively propose a dip-coating method with modified gel solutions to obtain defect-free, functional ion gel layers without the issues arising from the spin-coating method for 3D device fabrication. A dip-coating approach offers a single-step coating solution with the benefits of simplicity, scalability, and high throughput for deposition of high-capacitance gel layers on non-planar EWOD devices. An ion gel solution was prepared by combining the [EMIM][TFSI] ionic liquid and the [P(VDF-HFP)] copolymer at various wt % ratios in acetone solvent. Experimental studies were conducted to fully understand the effects of chemical composition ratios in the gel solution and how varying thicknesses of ion gel and Teflon layers affects EWOD performance. The effectiveness and potentiality of dip-coatable gel layers for 3D EWOD devices have been demonstrated through fabricating 5 × 1 arrayed liquid prisms using a single-step dip-coating method. Each prism module has been individually controlled to achieve spatial beam steering without the need for bulky mechanical moving parts. PMID:28772400

A Study of Dip-Coatable, High-Capacitance Ion Gel Dielectrics for 3D EWOD Device Fabrication.

PubMed

Clement, Carlos E; Jiang, Dongyue; Thio, Si Kuan; Park, Sung-Yong

2017-01-05

We present a dip-coatable, high-capacitance ion gel dielectric for scalable fabrication of three-dimensional (3D) electrowetting-on-dielectric (EWOD) devices such as an n × n liquid prism array. Due to the formation of a nanometer-thick electric double layer (EDL) capacitor, an ion gel dielectric offers two to three orders higher specific capacitance ( c ≈ 10 μF/cm²) than that of conventional dielectrics such as SiO₂. However, the previous spin-coating method used for gel layer deposition poses several issues for 3D EWOD device fabrication, particularly when assembling multiple modules. Not only does the spin-coating process require multiple repetitions per module, but the ion gel layer also comes in risks of damage or contamination due to handling errors caused during assembly. In addition, it was observed that the chemical formulation previously used for the spin-coating method causes the surface defects on the dip-coated gel layers and thus leads to poor EWOD performance. In this paper, we alternatively propose a dip-coating method with modified gel solutions to obtain defect-free, functional ion gel layers without the issues arising from the spin-coating method for 3D device fabrication. A dip-coating approach offers a single-step coating solution with the benefits of simplicity, scalability, and high throughput for deposition of high-capacitance gel layers on non-planar EWOD devices. An ion gel solution was prepared by combining the [EMIM][TFSI] ionic liquid and the [P(VDF-HFP)] copolymer at various wt % ratios in acetone solvent. Experimental studies were conducted to fully understand the effects of chemical composition ratios in the gel solution and how varying thicknesses of ion gel and Teflon layers affects EWOD performance. The effectiveness and potentiality of dip-coatable gel layers for 3D EWOD devices have been demonstrated through fabricating 5 × 1 arrayed liquid prisms using a single-step dip-coating method. Each prism module has been individually controlled to achieve spatial beam steering without the need for bulky mechanical moving parts.

Method for double-sided processing of thin film transistors

DOEpatents

Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.; Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang

2008-04-08

This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

Highly Flexible and Efficient Fabric-Based Organic Light-Emitting Devices for Clothing-Shaped Wearable Displays.

PubMed

Choi, Seungyeop; Kwon, Seonil; Kim, Hyuncheol; Kim, Woohyun; Kwon, Jung Hyun; Lim, Myung Sub; Lee, Ho Seung; Choi, Kyung Cheol

2017-07-25

Recently, the role of clothing has evolved from merely body protection, maintaining the body temperature, and fashion, to advanced functions such as various types of information delivery, communication, and even augmented reality. With a wireless internet connection, the integration of circuits and sensors, and a portable power supply, clothes become a novel electronic device. Currently, the information display is the most intuitive interface using visualized communication methods and the simultaneous concurrent processing of inputs and outputs between a wearer and functional clothes. The important aspect in this case is to maintain the characteristic softness of the fabrics even when electronic devices are added to the flexible clothes. Silicone-based light-emitting diode (LED) jackets, shirts, and stage costumes have started to appear, but the intrinsic stiffness of inorganic semiconductors causes wearers to feel discomfort; thus, it is difficult to use such devices for everyday purposes. To address this problem, a method of fabricating a thin and flexible emitting fabric utilizing organic light-emitting diodes (OLEDs) was developed in this work. Its flexibility was evaluated, and an analysis of its mechanical bending characteristics and tests of its long-term reliability were carried out.

3D printing for health & wealth: Fabrication of custom-made medical devices through additive manufacturing

NASA Astrophysics Data System (ADS)

Colpani, Alessandro; Fiorentino, Antonio; Ceretti, Elisabetta

2018-05-01

Additive Manufacturing (AM) differs from traditional manufacturing technologies by its ability to handle complex shapes with great design flexibility. These features make the technique suitable to fabricate customized components, particularly answering specific custom needs. Although AM mainly referred to prototyping, nowadays the interest in direct manufacturing of actual parts is growing. This article shows the application of AM within the project 3DP-4H&W (3D Printing for Health & Wealth) which involves engineers and physicians for developing pediatric custom-made medical devices to enhance the fulfilling of the patients specific needs. In the project, two types of devices made of a two-component biocompatible silicone are considered. The first application (dental field) consists in a device for cleft lip and palate. The second one (audiological field) consists in an acoustic prosthesis. The geometries of the devices are based on the anatomy of the patient that is obtained through a 3D body scan process. For both devices, two different approaches were planned, namely direct AM and indirect Rapid Tooling (RT). In particular, direct AM consists in the FDM processing of silicone, while RT consists in molds FDM fabrication followed by silicone casting. This paper presents the results of the RT method that is articulated in different phases: the acquisition of the geometry to be realized, the design of the molds taking into account the casting feasibility (as casting channel, vents, part extraction), the realization of molds produced through AM, molds surface chemical finishing, pouring and curing of the silicone. The fabricated devices were evaluated by the physicians team that confirmed the effectiveness of the proposed procedure in fabricating the desired devices. Moreover, the procedure can be used as a general method to extend the range of applications to any custom-made device for anatomic districts, especially where complex shapes are present (as tracheal or maxillary prostheses).

Effects of Humidity and Temperature on Orange Dye-Based Organic Field Effect Transistors Fabricated at Different Gravity

NASA Astrophysics Data System (ADS)

Fatima, N.; Ahmed, M. M.; Karimov, Kh. S.

2017-11-01

This study reports the fabrication of organic field effect transistors (OFETs) using 3-[ethyl[4-[(4-nitrophenyl)azo]phenyl]amino]propanenitrile, usually known as Orange-Dye 25 (OD) and its composite with sugar. The study investigated the heat- and humidity-dependent electrical characteristics of the fabricated devices. Fabrication was carried out from the aqueous solution of the materials using different gravity conditions, i.e., at positive (normal) gravity (+1 g) and at negative gravity (-1 g). A thin layer (10-15 μm) of OD or OD:sugar was deposited by drop-casting on pre-fabricated drain and source silver (Ag) electrodes having 30 μm separation and 2 mm length followed by aluminum (Al) thermal evaporation to achieve a Schottky barrier. Devices fabricated using OD at -1 g were more sensitive in capacitance-temperature and impedance-humidity relationships than those fabricated at +1 g. Moreover, OFETs fabricated at -1 g using OD:sugar offered capacitance-temperature sensitivity much higher than the devices fabricated at +1 g. It has been observed that, in the drop-casting method, the properties of OFETs are dependent upon gravity as well as the solution composition employed for channel definition.

Method of fabricating germanium and gallium arsenide devices

NASA Technical Reports Server (NTRS)

Jhabvala, Murzban (Inventor)

1990-01-01

A method of semiconductor diode fabrication is disclosed which relies on the epitaxial growth of a precisely doped thickness layer of gallium arsenide or germanium on a semi-insulating or intrinsic substrate, respectively, of gallium arsenide or germanium by either molecular beam epitaxy (MBE) or by metal-organic chemical vapor deposition (MOCVD). The method involves: depositing a layer of doped or undoped silicon dioxide on a germanium or gallium arsenide wafer or substrate, selectively removing the silicon dioxide layer to define one or more surface regions for a device to be fabricated thereon, growing a matched epitaxial layer of doped germanium or gallium arsenide of an appropriate thickness using MBE or MOCVD techniques on both the silicon dioxide layer and the defined one or more regions; and etching the silicon dioxide and the epitaxial material on top of the silicon dioxide to leave a matched epitaxial layer of germanium or gallium arsenide on the germanium or gallium arsenide substrate, respectively, and upon which a field effect device can thereafter be formed.

Low-cost, solution processable carbon nanotube supercapacitors and their characterization

NASA Astrophysics Data System (ADS)

Lehtimäki, Suvi; Tuukkanen, Sampo; Pörhönen, Juho; Moilanen, Pasi; Virtanen, Jorma; Honkanen, Mari; Lupo, Donald

2014-06-01

We report ecological and low-cost carbon nanotube (CNT) supercapacitors fabricated using a simple, scalable solution processing method, where the use of a highly porous and electrically conductive active material eliminates the need for a current collector. Electrodes were fabricated on a poly(ethylene terephthalate) substrate from a printable multi-wall CNT ink, where the CNTs are solubilized in water using xylan as a dispersion agent. The dispersion method facilitates a very high concentration of CNTs in the ink. Supercapacitors were assembled using a paper separator and an aqueous NaCl electrolyte and the devices were characterized with a galvanostatic discharge method defined by an industrial standard. The capacitance of the 2 cm^2 devices was 6 mF/cm^2 (2.3 F/g) and equivalent series resistance 80 Ω . Low-cost supercapacitors fabricated from safe and environmentally friendly materials have potential applications as energy storage devices in ubiquitous and autonomous intelligence as well as in disposable low-end products.

Capability of Sputtered Micro-patterned NiTi Thick Films

NASA Astrophysics Data System (ADS)

Bechtold, Christoph; Lima de Miranda, Rodrigo; Quandt, Eckhard

2015-09-01

Today, most NiTi devices are manufactured by a combination of conventional metal fabrication steps, e.g., melting, extrusion, cold working, etc., and are subsequently structured by high accuracy laser cutting. This combination has been proven to be very successful; however, there are several limitations to this fabrication route, e.g., in respect to the fabrication of more complex device designs, device miniaturization or the combination of different materials for the integration of further functionality. These issues have to be addressed in order to develop new devices and applications. The fabrication of micro-patterned films using magnetron sputtering, UV lithography, and wet etching has great potential to overcome limitations of conventional device manufacturing. Due to its fabrication characteristics, this method allows the production of devices with complex designs, high structural accuracy, smooth edge profile, at layer thicknesses up to 75 µm. The aim of this study is to present recent developments in the field of NiTi thin film technology, its advantages and limitations, as well as new possible applications in the medical and in non-medical fields. These developments include among others NiTi scaffold structures covered with NiTi membranes for their potential use as filters, heart valve components or aneurysm treatments, as well as micro-actuators for consumable electronics or automotive applications.

Optical fabrication of large area photonic microstructures by spliced lens

NASA Astrophysics Data System (ADS)

Jin, Wentao; Song, Meng; Zhang, Xuehua; Yin, Li; Li, Hong; Li, Lin

2018-05-01

We experimentally demonstrate a convenient approach to fabricate large area photorefractive photonic microstructures by a spliced lens device. Large area two-dimensional photonic microstructures are optically induced inside an iron-doped lithium niobate crystal. The experimental setups of our method are relatively compact and stable without complex alignment devices. It can be operated in almost any optical laboratories. We analyze the induced triangular lattice microstructures by plane wave guiding, far-field diffraction pattern imaging and Brillouin-zone spectroscopy. By designing the spliced lens appropriately, the method can be easily extended to fabricate other complex large area photonic microstructures, such as quasicrystal microstructures. Induced photonic microstructures can be fixed or erased and re-recorded in the photorefractive crystal.

Novel optical interconnect devices and coupling methods applying self-written waveguide technology

NASA Astrophysics Data System (ADS)

Nakama, Kenichi; Mikami, Osamu

2011-05-01

For the use in cost-effective optical interconnection of opt-electronic printed wiring boards (OE-PWBs), we have developed novel optical interconnect devices and coupling methods simplifying board to board optical interconnect. All these are based on the self-written waveguide (SWW) technology by the mask-transfer method with light-curable resin. This method enables fabrication of arrayed M × N optical channels at one shot of UV light. Very precise patterns, as an example, optical rod with diameters of 50μm to 500μm, can be easily fabricated. The length of the fabricated patterns ,, typically up to about 1000μm , can be controlled by a spacer placed between the photomask and the substrate. Using these technologies, several new optical interfaces have been demonstrated. These are a chip VCSEL with an optical output rod and new coupling methods of "plug-in" alignment and "optical socket" based on SWW.

Fabrication of Microhotplates Based on Laser Micromachining of Zirconium Oxide

NASA Astrophysics Data System (ADS)

Oblov, Konstantin; Ivanova, Anastasia; Soloviev, Sergey; Samotaev, Nikolay; Lipilin, Alexandr; Vasiliev, Alexey; Sokolov, Andrey

We present a novel approach to the fabrication of MEMS devices, which can be used for gas sensors operating in harsh environment in wireless and autonomous information systems. MEMS platforms based on ZrO2/Y2O3 (YSZ) are applied in these devices. The methods of ceramic MEMS devices fabrication with laser micromachining are considered. It is shown that the application of YSZ membranes permits a decrease in MEMS power consumption at 4500C down to ∼75 mW at continuous heating and down to ∼ 1 mW at pulse heating mode. The application of the platforms is not restricted by gas sensors: they can be used for fast thermometers, bolometric matrices, flowmeteres and other MEMS devices working under harsh environmental conditions.

The Conductive Silver Nanowires Fabricated by Two-beam Laser Direct Writing on the Flexible Sheet.

PubMed

He, Gui-Cang; Zheng, Mei-Ling; Dong, Xian-Zi; Jin, Feng; Liu, Jie; Duan, Xuan-Ming; Zhao, Zhen-Sheng

2017-02-02

Flexible electrically conductive nanowires are now a key component in the fields of flexible devices. The achievement of metal nanowire with good flexibility, conductivity, compact and smooth morphology is recognized as one critical milestone for the flexible devices. In this study, a two-beam laser direct writing system is designed to fabricate AgNW on PET sheet. The minimum width of the AgNW fabricated by this method is 187 ± 34 nm with the height of 84 ± 4 nm. We have investigated the electrical resistance under different voltages and the applicable voltage per meter range is determined to be less than 7.5 × 10 3  V/m for the fabricated AgNW. The flexibility of the AgNW is very excellent, since the resistance only increases 6.63% even after the stretched bending of 2000 times at such a small bending radius of 1.0 mm. The proposed two-beam laser direct writing is an efficient method to fabricate AgNW on the flexible sheet, which could be applied in flexible micro/nano devices.

Incorporation of ZnO and their composite nanostructured material into a cotton fabric platform for wearable device applications.

PubMed

Veluswamy, Pandiyarasan; Sathiyamoorthy, Suhasini; Khan, Faizan; Ghosh, Aranya; Abhijit, Majumdar; Hayakawa, Yasuhiro; Ikeda, Hiroya

2017-02-10

The central idea of this paper is to innovate a new approach for the development of wearable device materials through the coating of cotton fabric with ZnO and Sb-/Ag-/ZnO composites. The study was designed in order to have a clear understanding of the role of ZnO as well as the modified composite thereof under investigation. Cotton fabric with uniform ZnO/ZnO-composite layers on the surface was successfully synthesized via a solvothermal method. The growth behaviors were investigated by comparing ZnO and ZnO-composites. The structural, morphological, chemical states, optical, electrical and thermopower properties of these fabrics were studied. Nanostructured ZnO-composite fabric had enhanced UV shielding with a value of 83.96. It is found that the ZnO-composite fabrics have increased electrical conductivity. The thermopower value of the ZnO-composite fabric could reach 471.9μVK -1 . Such materials are anticipated to be worthwhile as wearable electronic devices and as protective textiles. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multi-step Variable Height Photolithography for Valved Multilayer Microfluidic Devices.

PubMed

Brower, Kara; White, Adam K; Fordyce, Polly M

2017-01-27

Microfluidic systems have enabled powerful new approaches to high-throughput biochemical and biological analysis. However, there remains a barrier to entry for non-specialists who would benefit greatly from the ability to develop their own microfluidic devices to address research questions. Particularly lacking has been the open dissemination of protocols related to photolithography, a key step in the development of a replica mold for the manufacture of polydimethylsiloxane (PDMS) devices. While the fabrication of single height silicon masters has been explored extensively in literature, fabrication steps for more complicated photolithography features necessary for many interesting device functionalities (such as feature rounding to make valve structures, multi-height single-mold patterning, or high aspect ratio definition) are often not explicitly outlined. Here, we provide a complete protocol for making multilayer microfluidic devices with valves and complex multi-height geometries, tunable for any application. These fabrication procedures are presented in the context of a microfluidic hydrogel bead synthesizer and demonstrate the production of droplets containing polyethylene glycol (PEG diacrylate) and a photoinitiator that can be polymerized into solid beads. This protocol and accompanying discussion provide a foundation of design principles and fabrication methods that enables development of a wide variety of microfluidic devices. The details included here should allow non-specialists to design and fabricate novel devices, thereby bringing a host of recently developed technologies to their most exciting applications in biological laboratories.

Exploration of microfluidic devices based on multi-filament threads and textiles: A review

PubMed Central

Nilghaz, A.; Ballerini, D. R.; Shen, W.

2013-01-01

In this paper, we review the recent progress in the development of low-cost microfluidic devices based on multifilament threads and textiles for semi-quantitative diagnostic and environmental assays. Hydrophilic multifilament threads are capable of transporting aqueous and non-aqueous fluids via capillary action and possess desirable properties for building fluid transport pathways in microfluidic devices. Thread can be sewn onto various support materials to form fluid transport channels without the need for the patterned hydrophobic barriers essential for paper-based microfluidic devices. Thread can also be used to manufacture fabrics which can be patterned to achieve suitable hydrophilic-hydrophobic contrast, creating hydrophilic channels which allow the control of fluids flow. Furthermore, well established textile patterning methods and combination of hydrophilic and hydrophobic threads can be applied to fabricate low-cost microfluidic devices that meet the low-cost and low-volume requirements. In this paper, we review the current limitations and shortcomings of multifilament thread and textile-based microfluidics, and the research efforts to date on the development of fluid flow control concepts and fabrication methods. We also present a summary of different methods for modelling the fluid capillary flow in microfluidic thread and textile-based systems. Finally, we summarized the published works of thread surface treatment methods and the potential of combining multifilament thread with other materials to construct devices with greater functionality. We believe these will be important research focuses of thread- and textile-based microfluidics in future. PMID:24086179

Simplifying Nanowire Hall Effect Characterization by Using a Three-Probe Device Design.

PubMed

Hultin, Olof; Otnes, Gaute; Samuelson, Lars; Storm, Kristian

2017-02-08

Electrical characterization of nanowires is a time-consuming and challenging task due to the complexity of single nanowire device fabrication and the difficulty in interpreting the measurements. We present a method to measure Hall effect in nanowires using a three-probe device that is simpler to fabricate than previous four-probe nanowire Hall devices and allows characterization of nanowires with smaller diameter. Extraction of charge carrier concentration from the three-probe measurements using an analytical model is discussed and compared to simulations. The validity of the method is experimentally verified by a comparison between results obtained with the three-probe method and results obtained using four-probe nanowire Hall measurements. In addition, a nanowire with a diameter of only 65 nm is characterized to demonstrate the capabilities of the method. The three-probe Hall effect method offers a relatively fast and simple, yet accurate way to quantify the charge carrier concentration in nanowires and has the potential to become a standard characterization technique for nanowires.

Controlling release from 3D printed medical devices using CLIP and drug-loaded liquid resins.

PubMed

Bloomquist, Cameron J; Mecham, Michael B; Paradzinsky, Mark D; Janusziewicz, Rima; Warner, Samuel B; Luft, J Christopher; Mecham, Sue J; Wang, Andrew Z; DeSimone, Joseph M

2018-05-28

Mass customization along with the ability to generate designs using medical imaging data makes 3D printing an attractive method for the fabrication of patient-tailored drug and medical devices. Herein we describe the application of Continuous Liquid Interface Production (CLIP) as a method to fabricate biocompatible and drug-loaded devices with controlled release properties, using liquid resins containing active pharmaceutical ingredients (API). In this work, we characterize how the release kinetics of a model small molecule, rhodamine B-base (RhB), are affected by device geometry, network crosslink density, and the polymer composition of polycaprolactone- and poly (ethylene glycol)-based networks. To demonstrate the applicability of using API-loaded liquid resins with CLIP, the UV stability was evaluated for a panel of clinically-relevant small molecule drugs. Finally, select formulations were tested for biocompatibility, degradation and encapsulation of docetaxel (DTXL) and dexamethasone-acetate (DexAc). Formulations were shown to be biocompatible over the course of 175 days of in vitro degradation and the clinically-relevant drugs could be encapsulated and released in a controlled fashion. This study reveals the potential of the CLIP manufacturing platform to serve as a method for the fabrication of patient-specific medical and drug-delivery devices for personalized medicine. Copyright © 2018. Published by Elsevier B.V.

One-step patterning of hollow microstructures in paper by laser cutting to create microfluidic analytical devices.

PubMed

Nie, Jinfang; Liang, Yuanzhi; Zhang, Yun; Le, Shangwang; Li, Dunnan; Zhang, Songbai

2013-01-21

In this paper, we report a simple, low-cost method for rapid, highly reproductive fabrication of paper-based microfluidics by using a commercially available, minitype CO(2) laser cutting/engraving machine. This method involves only one operation of cutting a piece of paper by laser according to a predesigned pattern. The hollow microstructures formed in the paper are used as the 'hydrophobic barriers' to define the hydrophilic flowing paths. A typical paper device on a 4 cm × 4 cm piece of paper can be fabricated within ∼7-20 s; it is ready for use once the cutting process is finished. The main fabrication parameters such as the applied current and cutting rate of the laser were optimized. The fabrication resolution and multiplexed analytical capability of the hollow microstructure-patterned paper were also characterized.

Recent advances in low-cost microfluidic platforms for diagnostic applications.

PubMed

Tomazelli Coltro, Wendell Karlos; Cheng, Chao-Min; Carrilho, Emanuel; de Jesus, Dosil Pereira

2014-08-01

The use of inexpensive materials and cost-effective manufacturing processes for mass production of microfluidic devices is very attractive and has spurred a variety of approaches. Such devices are particularly suited for diagnostic applications in limited resource settings. This review describes the recent and remarkable advances in the use of low-cost substrates for the development of microfluidic devices for diagnostics and clinical assays. Thus, a plethora of new and improved fabrication methods, designs, capabilities, detections, and applications of microfluidic devices fabricated with paper, plastic, and threads are covered. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

40 CFR 60.275a - Test methods and procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... operator shall demonstrate compliance with § 60.272(a)(3) based on emissions from only the affected... used for negative-pressure fabric filters and other types of control devices and Method 5D shall be used for positive-pressure fabric filters to determine the particulate matter concentration and...

Droplet Microfluidics for Chip-Based Diagnostics

PubMed Central

Kaler, Karan V. I. S.; Prakash, Ravi

2014-01-01

Droplet microfluidics (DMF) is a fluidic handling technology that enables precision control over dispensing and subsequent manipulation of droplets in the volume range of microliters to picoliters, on a micro-fabricated device. There are several different droplet actuation methods, all of which can generate external stimuli, to either actively or passively control the shape and positioning of fluidic droplets over patterned substrates. In this review article, we focus on the operation and utility of electro-actuation-based DMF devices, which utilize one or more micro-/nano-patterned substrates to facilitate electric field-based handling of chemical and/or biological samples. The underlying theory of DMF actuations, device fabrication methods and integration of optical and opto-electronic detectors is discussed in this review. Example applications of such electro-actuation-based DMF devices have also been included, illustrating the various actuation methods and their utility in conducting chip-based laboratory and clinical diagnostic assays. PMID:25490590

Laser-assisted advanced assembly for MEMS fabrication

NASA Astrophysics Data System (ADS)

Atanasov, Yuriy Andreev

Micro Electro-Mechanical Systems (MEMS) are currently fabricated using methods originally designed for manufacturing semiconductor devices, using minimum if any assembly at all. The inherited limitations of this approach narrow the materials that can be employed and reduce the design complexity, imposing limitations on MEMS functionality. The proposed Laser-Assisted Advanced Assembly (LA3) method solves these problems by first fabricating components followed by assembly of a MEMS device. Components are micro-machined using a laser or by photolithography followed by wet/dry etching out of any material available in a thin sheet form. A wide range of materials can be utilized, including biocompatible metals, ceramics, polymers, composites, semiconductors, and materials with special properties such as memory shape alloys, thermoelectric, ferromagnetic, piezoelectric, and more. The approach proposed allows enhancing the structural and mechanical properties of the starting materials through heat treatment, tribological coatings, surface modifications, bio-functionalization, and more, a limited, even unavailable possibility with existing methods. Components are transferred to the substrate for assembly using the thermo-mechanical Selective Laser Assisted Die Transfer (tmSLADT) mechanism for microchips assembly, already demonstrated by our team. Therefore, the mechanical and electronic part of the MEMS can be fabricated using the same equipment/method. The viability of the Laser-Assisted Advanced Assembly technique for MEMS is demonstrated by fabricating magnetic switches for embedding in a conductive carbon-fiber metamaterial for use in an Electromagnetic-Responsive Mobile Cyber-Physical System (E-RMCPS), which is expected to improve the wireless communication system efficiency within a battery-powered device.

Direct writing electrodes using a ball pen for paper-based point-of-care testing.

PubMed

Li, Zedong; Li, Fei; Hu, Jie; Wee, Wei Hong; Han, Yu Long; Pingguan-Murphy, Belinda; Lu, Tian Jian; Xu, Feng

2015-08-21

The integration of paper with an electrochemical device has attracted growing attention for point-of-care testing, where it is of great importance to fabricate electrodes on paper in a low-cost, easy and versatile way. In this work, we report a simple strategy for directly writing electrodes on paper using a pressure-assisted ball pen to form a paper-based electrochemical device (PED). This method is demonstrated to be capable of fabricating electrodes on paper with good electrical conductivity and electrochemical performance, holding great potential to be employed in point-of-care applications, such as in human health diagnostics and food safety detection. As examples, the PEDs fabricated using the developed method are applied for detection of glucose in artificial urine and melamine in sample solutions. Furthermore, our developed strategy is also extended to fabricate PEDs with multi-electrode arrays and write electrodes on non-planar surfaces (e.g., paper cup, human skin), indicating the potential application of our method in other fields, such as fabricating biosensors, paper electronics etc.

Photovoltaic device using single wall carbon nanotubes and method of fabricating the same

DOEpatents

Biris, Alexandru S.; Li, Zhongrui

2012-11-06

A photovoltaic device and methods for forming the same. In one embodiment, the photovoltaic device has a silicon substrate, and a film comprising a plurality of single wall carbon nanotubes disposed on the silicon substrate, wherein the plurality of single wall carbon nanotubes forms a plurality of heterojunctions with the silicon in the substrate.

Use of Vacuum Bagging for Fabricating Thermoplastic Microfluidic Devices

PubMed Central

Cassano, Christopher L.; Simon, Andrew J.; Liu, Wei; Fredrickson, Carl; Fan, Z. Hugh

2014-01-01

In this work we present a novel thermal bonding method for thermoplastic microfluidic devices. This simple method employs a modified vacuum bagging technique, a concept borrowed from the aerospace industry, to produce conventional thick substrate microfluidic devices, as well as multi-layer film devices. The bonds produced using this method are superior to those obtained using conventional thermal bonding methods, including thermal lamination, and are capable of sustaining burst pressures in excess of 550 kPa. To illustrate the utility of this method, thick substrate devices were produced, as well as a six-layer film device that incorporated several complex features. PMID:25329244

Method for fabricating an interconnected array of semiconductor devices

DOEpatents

Grimmer, Derrick P.; Paulson, Kenneth R.; Gilbert, James R.

1989-10-10

Semiconductor layer and conductive layer formed on a flexible substrate, divided into individual devices and interconnected with one another in series by interconnection layers and penetrating terminals.

Low-loss integrated electrical surface plasmon source with ultra-smooth metal film fabricated by polymethyl methacrylate 'bond and peel' method.

PubMed

Liu, Wenjie; Hu, Xiaolong; Zou, Qiushun; Wu, Shaoying; Jin, Chongjun

2018-06-15

External light sources are mostly employed to functionalize the plasmonic components, resulting in a bulky footprint. Electrically driven integrated plasmonic devices, combining ultra-compact critical feature sizes with extremely high transmission speeds and low power consumption, can link plasmonics with the present-day electronic world. In an effort to achieve this prospect, suppressing the losses in the plasmonic devices becomes a pressing issue. In this work, we developed a novel polymethyl methacrylate 'bond and peel' method to fabricate metal films with sub-nanometer smooth surfaces on semiconductor wafers. Based on this method, we further fabricated a compact plasmonic source containing a metal-insulator-metal (MIM) waveguide with an ultra-smooth metal surface on a GaAs-based light-emitting diode wafer. An increase in propagation length of the SPP mode by a factor of 2.95 was achieved as compared with the conventional device containing a relatively rough metal surface. Numerical calculations further confirmed that the propagation length is comparable to the theoretical prediction on the MIM waveguide with perfectly smooth metal surfaces. This method facilitates low-loss and high-integration of electrically driven plasmonic devices, thus provides an immediate opportunity for the practical application of on-chip integrated plasmonic circuits.

Low-loss integrated electrical surface plasmon source with ultra-smooth metal film fabricated by polymethyl methacrylate ‘bond and peel’ method

NASA Astrophysics Data System (ADS)

Liu, Wenjie; Hu, Xiaolong; Zou, Qiushun; Wu, Shaoying; Jin, Chongjun

2018-06-01

External light sources are mostly employed to functionalize the plasmonic components, resulting in a bulky footprint. Electrically driven integrated plasmonic devices, combining ultra-compact critical feature sizes with extremely high transmission speeds and low power consumption, can link plasmonics with the present-day electronic world. In an effort to achieve this prospect, suppressing the losses in the plasmonic devices becomes a pressing issue. In this work, we developed a novel polymethyl methacrylate ‘bond and peel’ method to fabricate metal films with sub-nanometer smooth surfaces on semiconductor wafers. Based on this method, we further fabricated a compact plasmonic source containing a metal-insulator-metal (MIM) waveguide with an ultra-smooth metal surface on a GaAs-based light-emitting diode wafer. An increase in propagation length of the SPP mode by a factor of 2.95 was achieved as compared with the conventional device containing a relatively rough metal surface. Numerical calculations further confirmed that the propagation length is comparable to the theoretical prediction on the MIM waveguide with perfectly smooth metal surfaces. This method facilitates low-loss and high-integration of electrically driven plasmonic devices, thus provides an immediate opportunity for the practical application of on-chip integrated plasmonic circuits.

Method of forming crystalline silicon devices on glass

DOEpatents

McCarthy, Anthony M.

1995-01-01

A method for fabricating single-crystal silicon microelectronic components on a silicon substrate and transferring same to a glass substrate. This is achieved by utilizing conventional silicon processing techniques for fabricating components of electronic circuits and devices on bulk silicon, wherein a bulk silicon surface is prepared with epitaxial layers prior to the conventional processing. The silicon substrate is bonded to a glass substrate and the bulk silicon is removed leaving the components intact on the glass substrate surface. Subsequent standard processing completes the device and circuit manufacturing. This invention is useful in applications requiring a transparent or insulating substrate, particularly for display manufacturing. Other applications include sensors, actuators, optoelectronics, radiation hard electronics, and high temperature electronics.

Studies of geometrical profiling in fabricated tapered optical fibers using whispering gallery modes spectroscopy

NASA Astrophysics Data System (ADS)

Kavungal, Vishnu; Farrell, Gerald; Wu, Qiang; Kumar Mallik, Arun; Semenova, Yuliya

2018-03-01

This paper experimentally demonstrates a method for geometrical profiling of asymmetries in fabricated thin microfiber tapers with waist diameters ranging from ∼10 to ∼50 μm with submicron accuracy. The method is based on the analysis of whispering gallery mode resonances excited in cylindrical fiber resonators as a result of evanescent coupling of light propagating through the fiber taper. The submicron accuracy of the proposed method has been verified by SEM studies. The method can be applied as a quality control tool in fabrication of microfiber based devices and sensors or for fine-tuning of microfiber fabrication set-ups.

Development of Deposition and Characterization Systems for Thin Film Solar Cells

NASA Astrophysics Data System (ADS)

Cimaroli, Alexander J.

Photovoltaic (PV) devices are becoming more important due to a number of economic and environmental factors. PV research relies on the ability to quickly fabricate and characterize these devices. While there are a number of deposition methods that are available in a laboratory setting, they are not necessarily able to be scaled to provide high throughput in a commercial setting. A close-space sublimation (CSS) system was developed to provide a means of depositing thin films in a very controlled and scalable manner. Its viability was explored by using it to deposit the absorber layer in Zn3P2 and CdTe solar cell devices. Excellent control over morphology and growth conditions and a high level of repeatability was demonstrated in the study of textured Zn3P2 thin films. However, some limitations imposed by the structure of Zn3P 2-based PV devices showed that CSS may not be the best approach for depositing Zn3P2 thin films. Despite the inability to make Zn3P2 solar cell devices, high efficiency CdTe solar cells were fabricated using CSS. With the introduction of Perovskite-based solar cell devices, the viability of data collected from conventional J-V measurements was questioned due to the J-V hysteresis that Perovskite devices exhibited. New methods of solar cell characterization were developed in order to accurately and quickly assess the performance of hysteretic PV devices. Both J-V measurements and steady-state efficiency measurements are prone to errors due to hysteresis and maximum power point drift. To resolve both of these issues, a maximum power point tracking (MPPT) system was developed with two algorithms: a simple algorithm and a predictive algorithm. The predictive algorithm showed increased resistance to the effects of hysteresis because of its ability to predict the steady-state current after a bias step with a double exponential decay model fit. Some publications have attempted to quantify the degree of J-V hysteresis present in fabricated Perovskite-based devices, but the analysis relied on J-V measurements. The sweep rate, starting bias, illumination time, etc. would affect the value of the calculated degree of hysteresis. A method of using transient photocurrent measurements is presented to accurately quantify the degree of hysteresis for all solar cells: not just Perovskite-based devices. According to this method, almost all solar cell devices exhibit several forms of J-V hysteresis. This method may open new ways of analyzing the defects in fabricated PV devices.

Solar cell collector

NASA Technical Reports Server (NTRS)

Evans, J. C., Jr. (Inventor)

1978-01-01

A method is provided for the fabrication of a photovoltaic device which possesses an efficient collector system for the conduction of the current generated by incident photons to the external circuitry of the device.

Semiconductor-based, large-area, flexible, electronic devices

DOEpatents

Goyal, Amit [Knoxville, TN

2011-03-15

Novel articles and methods to fabricate the same resulting in flexible, large-area, triaxially textured, single-crystal or single-crystal-like, semiconductor-based, electronic devices are disclosed. Potential applications of resulting articles are in areas of photovoltaic devices, flat-panel displays, thermophotovoltaic devices, ferroelectric devices, light emitting diode devices, computer hard disc drive devices, magnetoresistance based devices, photoluminescence based devices, non-volatile memory devices, dielectric devices, thermoelectric devices and quantum dot laser devices.

Semiconductor-based, large-area, flexible, electronic devices on {110}<100> oriented substrates

DOEpatents

Goyal, Amit

2014-08-05

Novel articles and methods to fabricate the same resulting in flexible, oriented, semiconductor-based, electronic devices on {110}<100> textured substrates are disclosed. Potential applications of resulting articles are in areas of photovoltaic devices, flat-panel displays, thermophotovoltaic devices, ferroelectric devices, light emitting diode devices, computer hard disc drive devices, magnetoresistance based devices, photoluminescence based devices, non-volatile memory devices, dielectric devices, thermoelectric devices and quantum dot laser devices.

[100] or [110] aligned, semiconductor-based, large-area, flexible, electronic devices

DOEpatents

Goyal, Amit

2015-03-24

Novel articles and methods to fabricate the same resulting in flexible, large-area, [100] or [110] textured, semiconductor-based, electronic devices are disclosed. Potential applications of resulting articles are in areas of photovoltaic devices, flat-panel displays, thermophotovoltaic devices, ferroelectric devices, light emitting diode devices, computer hard disc drive devices, magnetoresistance based devices, photoluminescence based devices, non-volatile memory devices, dielectric devices, thermoelectric devices and quantum dot laser devices.

Additive manufacturing of lab-on-a-chip devices: promises and challenges

NASA Astrophysics Data System (ADS)

Zhu, Feng; Macdonald, Niall P.; Cooper, Jonathan M.; Wlodkowic, Donald

2013-12-01

This work describes a preliminary investigation of commercially available 3D printing technologies for rapid prototyping and low volume fabrication of Lab-on-a-Chip devices. The main motivation of the work was to use off-the-shelf 3D printing methods in order to rapidly and inexpensively build microfluidic devices with complex geometric features and reduce the need to use clear room environment and conventional microfabrication techniques. Both multi-jet modelling (MJM) and stereolithography (SLA) processes were explored. MJM printed devices were fabricated using a HD3500+ (3D Systems) high-definition printer using a thermo-polymer VisiJet Crystal (3D Systems) substratum that allows for a z-axis resolution of 16 μm and 25 μm x-y accuracy. SLA printed devices were produced using a Viper Pro (3D Systems) stereolithography system using Watershed 11122XC (DSM Somos) and Dreve Fototec 7150 Clear (Dreve Otoplastik GmbH) resins which allow for a z-axis resolution of 50 μm and 25 μm x-y accuracy. Fabrication results compared favourably with other forms of rapid prototyping such as laser cut PMMA devices and PDMS moulded microfluidic devices of the same design. Both processes allowed for fabrication of monolithic, optically transparent devices with features in the 100 μm range requiring minimal post-processing. Optical polymer qualities following different post-processing methods were also tested in both brightfield and fluorescence imaging of transgenic zebrafish embryos. Finally, we show that only ethanol-treated Dreve Fototec 7150 Clear resign proved to be non-toxic to human cell lines and fish embryos in fish toxicity assays (FET) requiring further investigation of 3D printing materials.

Review on recent Developments on Fabrication Techniques of Distributed Feedback (DFB) Based Organic Lasers

NASA Astrophysics Data System (ADS)

Azrina Talik, Noor; Boon Kar, Yap; Noradhlia Mohamad Tukijan, Siti; Wong, Chuan Ling

2017-10-01

To date, the state of art organic semiconductor distributed feedback (DFB) lasers gains tremendous interest in the organic device industry. This paper presents a short reviews on the fabrication techniques of DFB based laser by focusing on the fabrication method of DFB corrugated structure and the deposition of organic gain on the nano-patterned DFB resonator. The fabrication techniques such as Laser Direct Writing (LDW), ultrafast photo excitation dynamics, Laser Interference Lithography (LIL) and Nanoimprint Lithography (NIL) for DFB patterning are presented. In addition to that, the method for gain medium deposition method is also discussed. The technical procedures of the stated fabrication techniques are summarized together with their benefits and comparisons to the traditional fabrication techniques.

Fabrication of hybrid molecular devices using multi-layer graphene break junctions.

PubMed

Island, J O; Holovchenko, A; Koole, M; Alkemade, P F A; Menelaou, M; Aliaga-Alcalde, N; Burzurí, E; van der Zant, H S J

2014-11-26

We report on the fabrication of hybrid molecular devices employing multi-layer graphene (MLG) flakes which are patterned with a constriction using a helium ion microscope or an oxygen plasma etch. The patterning step allows for the localization of a few-nanometer gap, created by electroburning, that can host single molecules or molecular ensembles. By controlling the width of the sculpted constriction, we regulate the critical power at which the electroburning process begins. We estimate the flake temperature given the critical power and find that at low powers it is possible to electroburn MLG with superconducting contacts in close proximity. Finally, we demonstrate the fabrication of hybrid devices with superconducting contacts and anthracene-functionalized copper curcuminoid molecules. This method is extendable to spintronic devices with ferromagnetic contacts and a first step towards molecular integrated circuits.

Fabrication of hybrid molecular devices using multi-layer graphene break junctions

NASA Astrophysics Data System (ADS)

Island, J. O.; Holovchenko, A.; Koole, M.; Alkemade, P. F. A.; Menelaou, M.; Aliaga-Alcalde, N.; Burzurí, E.; van der Zant, H. S. J.

2014-11-01

We report on the fabrication of hybrid molecular devices employing multi-layer graphene (MLG) flakes which are patterned with a constriction using a helium ion microscope or an oxygen plasma etch. The patterning step allows for the localization of a few-nanometer gap, created by electroburning, that can host single molecules or molecular ensembles. By controlling the width of the sculpted constriction, we regulate the critical power at which the electroburning process begins. We estimate the flake temperature given the critical power and find that at low powers it is possible to electroburn MLG with superconducting contacts in close proximity. Finally, we demonstrate the fabrication of hybrid devices with superconducting contacts and anthracene-functionalized copper curcuminoid molecules. This method is extendable to spintronic devices with ferromagnetic contacts and a first step towards molecular integrated circuits.

Energy harvesting: an integrated view of materials, devices and applications.

PubMed

Radousky, H B; Liang, H

2012-12-21

Energy harvesting refers to the set of processes by which useful energy is captured from waste, environmental, or mechanical sources and is converted into a usable form. The discipline of energy harvesting is a broad topic that includes established methods and materials such as photovoltaics and thermoelectrics, as well as more recent technologies that convert mechanical energy, magnetic energy and waste heat to electricity. This article will review various state-of-the-art materials and devices for direct energy conversion and in particular will include multistep energy conversion approaches. The article will highlight the nano-materials science underlying energy harvesting principles and devices, but also include more traditional bulk processes and devices as appropriate and synergistic. Emphasis is placed on device-design innovations that lead to higher efficiency energy harvesting or conversion technologies ranging from the cm/mm-scale down to MEMS/NEMS (micro- and nano-electromechanical systems) devices. Theoretical studies are reviewed, which address transport properties, crystal chemistry, thermodynamic analysis, energy transfer, system efficiency and device operation. New developments in experimental methods; device design and fabrication; nanostructured materials fabrication; materials properties; and device performance measurement techniques are discussed.

Energy harvesting: an integrated view of materials, devices and applications

NASA Astrophysics Data System (ADS)

Radousky, H. B.; Liang, H.

2012-12-01

Energy harvesting refers to the set of processes by which useful energy is captured from waste, environmental, or mechanical sources and is converted into a usable form. The discipline of energy harvesting is a broad topic that includes established methods and materials such as photovoltaics and thermoelectrics, as well as more recent technologies that convert mechanical energy, magnetic energy and waste heat to electricity. This article will review various state-of-the-art materials and devices for direct energy conversion and in particular will include multistep energy conversion approaches. The article will highlight the nano-materials science underlying energy harvesting principles and devices, but also include more traditional bulk processes and devices as appropriate and synergistic. Emphasis is placed on device-design innovations that lead to higher efficiency energy harvesting or conversion technologies ranging from the cm/mm-scale down to MEMS/NEMS (micro- and nano-electromechanical systems) devices. Theoretical studies are reviewed, which address transport properties, crystal chemistry, thermodynamic analysis, energy transfer, system efficiency and device operation. New developments in experimental methods; device design and fabrication; nanostructured materials fabrication; materials properties; and device performance measurement techniques are discussed.

MEMS for Tunable Photonic Metamaterial Applications

NASA Astrophysics Data System (ADS)

Stark, Thomas

Photonic metamaterials are materials whose optical properties are derived from artificially-structured sub-wavelength unit cells, rather than from the bulk properties of the constituent materials. Examples of metamaterials include plasmonic materials, negative index materials, and electromagnetic cloaks. While advances in simulation tools and nanofabrication methods have allowed this field to grow over the past several decades, many challenges still exist. This thesis addresses two of these challenges: fabrication of photonic metamaterials with tunable responses and high-throughput nanofabrication methods for these materials. The design, fabrication, and optical characterization of a microelectromechanical systems (MEMS) tunable plasmonic spectrometer are presented. An array of holes in a gold film, with plasmon resonance in the mid-infrared, is suspended above a gold reflector, forming a Fabry-Perot interferometer of tunable length. The spectra exhibit the convolution of extraordinary optical transmission through the holes and Fabry-Perot resonances. Using MEMS, the interferometer length is modulated from 1.7 mum to 21.67 mum , thereby tuning the free spectral range from about 2900 wavenumbers to 230.7 wavenumbers and shifting the reflection minima and maxima across the infrared. Due to its broad spectral tunability in the fingerprint region of the mid-infrared, this device shows promise as a tunable biological sensing device. To address the issue of high-throughput, high-resolution fabrication of optical metamaterials, atomic calligraphy, a MEMS-based dynamic stencil lithography technique for resist-free fabrication of photonic metamaterials on unconventional substrates, has been developed. The MEMS consists of a moveable stencil, which can be actuated with nanometer precision using electrostatic comb drive actuators. A fabrication method and flip chip method have been developed, enabling evaporation of metals through the device handle for fabrication on an external substrate. While the MEMS can be used to fabricate over areas of approximately 100 square mum2, a piezoelectric step-and repeat system enables fabrication over cm length scales. Thus, this technique leverages the precision inherent to MEMS actuation, while enhancing nanofabrication thoughput. Fabricating metamaterials on new substrates will enable novel and tunable metamaterials. For example, by fabricating unit cells on a periodic auxetic mechanical scaffold, the optical properties can be tuned by straining the mechanical scaffold.

High-Speed Coating Method for Photovoltaic Textiles with Closed-Type Die Coater

NASA Astrophysics Data System (ADS)

Imai, Takahiko; Shibayama, Norihisa; Takamatsu, Seiichi; Shiraishi, Kenji; Marumoto, Kazuhiro; Itoh, Toshihiro

2013-06-01

We developed a closed-type die-coating method to fabricate thin films for electronic devices. We succeeded in the die-coating of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) water dispersions and regioregular poly(3-hexylthiophene):[6,6]-phenyl C61-butyric acid methyl ester (P3HT:PCBM) solution to fabricate thin films of these organic materials with extremely high speeds of 5 and 20 m/min, respectively. The film thicknesses were evaluated by cross-sectional scanning electron microscopy (SEM). The deviations of the film thicknesses from our target values were less than 5%. We fabricated Al/P3HT:PCBM/PEDOT:PSS/indium tin oxide (ITO)/poly(ethylene terephthalate) (PET) textiles as an example of an application of the method, and the photovoltaic characteristic of the devices was confirmed.

Method for fabricating pixelated silicon device cells

DOEpatents

Nielson, Gregory N.; Okandan, Murat; Cruz-Campa, Jose Luis; Nelson, Jeffrey S.; Anderson, Benjamin John

2015-08-18

A method, apparatus and system for flexible, ultra-thin, and high efficiency pixelated silicon or other semiconductor photovoltaic solar cell array fabrication is disclosed. A structure and method of creation for a pixelated silicon or other semiconductor photovoltaic solar cell array with interconnects is described using a manufacturing method that is simplified compared to previous versions of pixelated silicon photovoltaic cells that require more microfabrication steps.

Progress Report for the Joint Services Electronics Program

DTIC Science & Technology

1991-06-30

AIGaAs MODFET layers. Both wet etching and reactive ion etching have been used to fabricate the channels. The CAIBE method will also be investigated in...potential for fabricating nanometer scale device structures through surface modification of various types. Using this JSEP research as a foundation...Kerkhoven, "Calculation of velocity overshoot in submicron devices using an augmented drift-diffusion model," Solid-State Electron. (to appear). (JSEP/NSF

Fabricating Simple Wax Screen-Printing Paper-Based Analytical Devices to Demonstrate the Concept of Limiting Reagent in Acid- Base Reactions

ERIC Educational Resources Information Center

Namwong, Pithakpong; Jarujamrus, Purim; Amatatongchai, Maliwan; Chairam, Sanoe

2018-01-01

In this article, a low-cost, simple, and rapid fabrication of paper-based analytical devices (PADs) using a wax screen-printing method is reported here. The acid-base reaction is implemented in the simple PADs to demonstrate to students the chemistry concept of a limiting reagent. When a fixed concentration of base reacts with a gradually…

Methods for batch fabrication of cold cathode vacuum switch tubes

DOEpatents

Walker, Charles A [Albuquerque, NM; Trowbridge, Frank R [Albuquerque, NM

2011-05-10

Methods are disclosed for batch fabrication of vacuum switch tubes that reduce manufacturing costs and improve tube to tube uniformity. The disclosed methods comprise creating a stacked assembly of layers containing a plurality of adjacently spaced switch tube sub-assemblies aligned and registered through common layers. The layers include trigger electrode layer, cathode layer including a metallic support/contact with graphite cathode inserts, trigger probe sub-assembly layer, ceramic (e.g. tube body) insulator layer, and metallic anode sub-assembly layer. Braze alloy layers are incorporated into the stacked assembly of layers, and can include active metal braze alloys or direct braze alloys, to eliminate costs associated with traditional metallization of the ceramic insulator layers. The entire stacked assembly is then heated to braze/join/bond the stack-up into a cohesive body, after which individual switch tubes are singulated by methods such as sawing. The inventive methods provide for simultaneously fabricating a plurality of devices as opposed to traditional methods that rely on skilled craftsman to essentially hand build individual devices.

Simple and inexpensive microfluidic devices for the generation of monodisperse multiple emulsions

NASA Astrophysics Data System (ADS)

Li, Er Qiang; Zhang, Jia Ming; Thoroddsen, Sigurdur T.

2014-01-01

Droplet-based microfluidic devices have become a preferred versatile platform for various fields in physics, chemistry and biology. Polydimethylsiloxane soft lithography, the mainstay for fabricating microfluidic devices, usually requires the usage of expensive apparatus and a complex manufacturing procedure. Here, we report the design and fabrication of simple and inexpensive microfluidic devices based on microscope glass slides and pulled glass capillaries, for generating monodisperse multiple emulsions. The advantages of our method lie in a simple manufacturing procedure, inexpensive processing equipment and flexibility in the surface modification of the designed microfluidic devices. Different types of devices have been designed and tested and the experimental results demonstrated their robustness for preparing monodisperse single, double, triple and multi-component emulsions.

Flexible microfluidic devices with three-dimensional interconnected microporous walls for gas and liquid applications.

PubMed

Yuen, Po Ki; DeRosa, Michael E

2011-10-07

This article presents a simple, low-cost method of fabrication and the applications of flexible polystyrene microfluidic devices with three-dimensional (3D) interconnected microporous walls based on treatment using a solvent/non-solvent mixture at room temperature. The complete fabrication process from device design concept to working device can be completed in less than an hour in a regular laboratory setting, without the need for expensive equipment. Microfluidic devices were used to demonstrate gas generation and absorption reactions by acidifying water with carbon dioxide (CO(2)) gas. By selectively treating the microporous structures with oxygen plasma, acidification of water by acetic acid (distilled white vinegar) perfusion was also demonstrated with the same device design.

Multijunction photovoltaic device and fabrication method

DOEpatents

Arya, Rajeewa R.; Catalano, Anthony W.

1993-09-21

A multijunction photovoltaic device includes first and second amorphous silicon PIN photovoltaic cells in a stacked arrangement. An interface layer, composed of a doped silicon compound, is disposed between the two cells and has a lower bandgap than the respective n- and p-type adjacent layers of the first and second cells. The interface layer forms an ohmic contact with the one or the adjacent cell layers of the same conductivity type, and a tunnel junction with the other of the adjacent cell layers. The disclosed device is fabricated by a glow discharge process.

Development of Device Quality Nonlinear Optical Materials and Definition of Mechanisms of Optical Nonlinearity

DTIC Science & Technology

1994-09-01

Methods. We arbitrarily divide sequential synthesis methods into the following four categories: (1) traditional Langmuir - Blodgett methods, (2) techniques... Langmuir - Blodgett methods. Films from small amphiphilic molecules, fabricated by Langmuir - Blodgett methods, have been extensively investigated.", 48 -54,67...fabrication of Langmuir - Blodgett films. We shall see in the next section that photochemical reactions can be used to define buried channel waveguides

Self-aligned photolithography for the fabrication of fully transparent high-voltage devices

NASA Astrophysics Data System (ADS)

Zhang, Yonghui; Mei, Zengxia; Huo, Wenxing; Wang, Tao; Liang, Huili; Du, Xiaolong

2018-05-01

High-voltage devices, working in the range of hundreds of volts, are indispensable elements in the driving or readout circuits for various kinds of displays, integrated microelectromechanical systems and x-ray imaging sensors. However, the device performances are found hardly uniform or repeatable due to the misalignment issue, which are extremely common for offset drain high-voltage devices. To resolve this issue, this article reports a set of self-aligned photolithography technology for the fabrication of high-voltage devices. High-performance fully-transparent high-voltage thin film transistors, diodes and logic inverters are successfully fabricated with this technology. Unlike other self-aligned routes, opaque masks are introduced on the backside of the transparent substrate to facilitate proximity exposure method. The photolithography process is simulated and analyzed with technology computer aided design simulation to explain the working principle of the proximity exposure method. The substrate thickness is found to be vital for the implementation of this technology based on both simulation and experimental results. The electrical performance of high-voltage devices is dependent on the offset length, which can be delicately modulated by changing the exposure dose. The presented self-aligned photolithography technology is proved to be feasible in high-voltage circuits, demonstrating its huge potential in practical industrial applications.

A simple method of fabricating mask-free microfluidic devices for biological analysis

PubMed Central

Yi, Xin; Kodzius, Rimantas; Gong, Xiuqing; Xiao, Kang; Wen, Weijia

2010-01-01

We report a simple, low-cost, rapid, and mask-free method to fabricate two-dimensional (2D) and three-dimensional (3D) microfluidic chip for biological analysis researches. In this fabrication process, a laser system is used to cut through paper to form intricate patterns and differently configured channels for specific purposes. Bonded with cyanoacrylate-based resin, the prepared paper sheet is sandwiched between glass slides (hydrophilic) or polymer-based plates (hydrophobic) to obtain a multilayer structure. In order to examine the chip’s biocompatibility and applicability, protein concentration was measured while DNA capillary electrophoresis was carried out, and both of them show positive results. With the utilization of direct laser cutting and one-step gas-sacrificing techniques, the whole fabrication processes for complicated 2D and 3D microfluidic devices are shorten into several minutes which make it a good alternative of poly(dimethylsiloxane) microfluidic chips used in biological analysis researches. PMID:20890452

Organic photovoltaic device with interfacial layer and method of fabricating same

DOEpatents

Marks, Tobin J.; Hains, Alexander W.

2013-03-19

An organic photovoltaic device and method of forming same. In one embodiment, the organic photovoltaic device has an anode, a cathode, an active layer disposed between the anode and the cathode; and an interfacial layer disposed between the anode and the active layer, the interfacial layer comprising 5,5'-bis[(p-trichlorosilylpropylphenyl)phenylamino]-2,2'-bithiophene (PABTSi.sub.2).

Stretchable V2O5/PEDOT supercapacitors: a modular fabrication process and charging with triboelectric nanogenerators.

PubMed

Qi, Ruijie; Nie, Jinhui; Liu, Mingyang; Xia, Mengyang; Lu, Xianmao

2018-04-26

Stretchable energy storage devices are of great importance for the viable applications of wearable/stretchable electronics. Studies on stretchable energy storage devices, especially supercapacitors (SCs), have shown encouraging progress. However, challenges still remain in the pursuit of high specific capacitances and facile fabrication methods. Herein, we report a modular materials fabrication and assembly process for stretchable SCs. With a V2O5/PEDOT composite as the active material, the resulting stretchable SCs exhibited high areal specific capacitances up to 240 mF cm-2 and good capacitance retention at a strain of 50%. To demonstrate the facile assembly process, a stretchable wristband was fabricated by simply assembling SC cells in series to deliver a voltage higher than 2 V. Charging the wristband with a triboelectric nanogenerator (TENG) to light an LED was further demonstrated, indicating the potential to integrate our SCs with environmental energy harvesters for self-powered stretchable devices.

A General Approach for Fluid Patterning and Application in Fabricating Microdevices.

PubMed

Huang, Zhandong; Yang, Qiang; Su, Meng; Li, Zheng; Hu, Xiaotian; Li, Yifan; Pan, Qi; Ren, Wanjie; Li, Fengyu; Song, Yanlin

2018-06-19

Engineering the fluid interface such as the gas-liquid interface is of great significance for solvent processing applications including functional material assembly, inkjet printing, and high-performance device fabrication. However, precisely controlling the fluid interface remains a great challenge owing to its flexibility and fluidity. Here, a general method to manipulate the fluid interface for fluid patterning using micropillars in the microchannel is reported. The principle of fluid patterning for immiscible fluid pairs including air, water, and oils is proposed. This understanding enables the preparation of programmable multiphase fluid patterns and assembly of multilayer functional materials to fabricate micro-optoelectronic devices. This general strategy of fluid patterning provides a promising platform to study the fundamental processes occurring on the fluid interface, and benefits applications in many subjects, such as microfluidics, microbiology, chemical analysis and detection, material synthesis and assembly, device fabrication, etc. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication and characterization of active nanostructures

NASA Astrophysics Data System (ADS)

Opondo, Noah F.

Three different nanostructure active devices have been designed, fabricated and characterized. Junctionless transistors based on highly-doped silicon nanowires fabricated using a bottom-up fabrication approach are first discussed. The fabrication avoids the ion implantation step since silicon nanowires are doped in-situ during growth. Germanium junctionless transistors fabricated with a top down approach starting from a germanium on insulator substrate and using a gate stack of high-k dielectrics and GeO2 are also presented. The levels and origin of low-frequency noise in junctionless transistor devices fabricated from silicon nanowires and also from GeOI devices are reported. Low-frequency noise is an indicator of the quality of the material, hence its characterization can reveal the quality and perhaps reliability of fabricated transistors. A novel method based on low-frequency noise measurement to envisage trap density in the semiconductor bandgap near the semiconductor/oxide interface of nanoscale silicon junctionless transistors (JLTs) is presented. Low-frequency noise characterization of JLTs biased in saturation is conducted at different gate biases. The noise spectrum indicates either a Lorentzian or 1/f. A simple analysis of the low-frequency noise data leads to the density of traps and their energy within the semiconductor bandgap. The level of noise in silicon JLT devices is lower than reported values on transistors fabricated using a top-down approach. This noise level can be significantly improved by improving the quality of dielectric and the channel interface. A micro-vacuum electron device based on silicon field emitters for cold cathode emission is also presented. The presented work utilizes vertical Si nanowires fabricated by means of self-assembly, standard lithography and etching techniques as field emitters in this dissertation. To obtain a high nanowire density, hence a high current density, a simple and inexpensive Langmuir Blodgett technique to deposit silica nanoparticles as a mask to etch Si is adopted. Fabrication and characterization of a metal-gated microtriode with a high current density and low operating voltage are presented.

{100}<100> or 45.degree.-rotated {100}<100>, semiconductor-based, large-area, flexible, electronic devices

DOEpatents

Goyal, Amit [Knoxville, TN

2012-05-15

Novel articles and methods to fabricate the same resulting in flexible, {100}<100> or 45.degree.-rotated {100}<100> oriented, semiconductor-based, electronic devices are disclosed. Potential applications of resulting articles are in areas of photovoltaic devices, flat-panel displays, thermophotovoltaic devices, ferroelectric devices, light emitting diode devices, computer hard disc drive devices, magnetoresistance based devices, photoluminescence based devices, non-volatile memory devices, dielectric devices, thermoelectric devices and quantum dot laser devices.

Resistive switching mechanism of ZnO/ZrO2-stacked resistive random access memory device annealed at 300 °C by sol-gel method with forming-free operation

NASA Astrophysics Data System (ADS)

Jian, Wen-Yi; You, Hsin-Chiang; Wu, Cheng-Yen

2018-01-01

In this work, we used a sol-gel process to fabricate a ZnO-ZrO2-stacked resistive switching random access memory (ReRAM) device and investigated its switching mechanism. The Gibbs free energy in ZnO, which is higher than that in ZrO2, facilitates the oxidation and reduction reactions of filaments in the ZnO layer. The current-voltage (I-V) characteristics of the device revealed a forming-free operation because of nonlattice oxygen in the oxide layer. In addition, the device can operate under bipolar or unipolar conditions with a reset voltage of 0 to ±2 V, indicating that in this device, Joule heating dominates at reset and the electric field dominates in the set process. Furthermore, the characteristics reveal why the fabricated device exhibits a greater discrete distribution phenomenon for the set voltage than for the reset voltage. These results will enable the fabrication of future ReRAM devices with double-layer oxide structures with improved characteristics.

Methods of forming semiconductor devices and devices formed using such methods

DOEpatents

Fox, Robert V; Rodriguez, Rene G; Pak, Joshua

2013-05-21

Single source precursors are subjected to carbon dioxide to form particles of material. The carbon dioxide may be in a supercritical state. Single source precursors also may be subjected to supercritical fluids other than supercritical carbon dioxide to form particles of material. The methods may be used to form nanoparticles. In some embodiments, the methods are used to form chalcopyrite materials. Devices such as, for example, semiconductor devices may be fabricated that include such particles. Methods of forming semiconductor devices include subjecting single source precursors to carbon dioxide to form particles of semiconductor material, and establishing electrical contact between the particles and an electrode.

Resistive switching effect in the planar structure of all-printed, flexible and rewritable memory device based on advanced 2D nanocomposite of graphene quantum dots and white graphene flakes

NASA Astrophysics Data System (ADS)

Muqeet Rehman, Muhammad; Uddin Siddiqui, Ghayas; Kim, Sowon; Choi, Kyung Hyun

2017-08-01

Pursuit of the most appropriate materials and fabrication methods is essential for developing a reliable, rewritable and flexible memory device. In this study, we have proposed an advanced 2D nanocomposite of white graphene (hBN) flakes embedded with graphene quantum dots (GQDs) as the functional layer of a flexible memory device owing to their unique electrical, chemical and mechanical properties. Unlike the typical sandwich type structure of a memory device, we developed a cost effective planar structure, to simplify device fabrication and prevent sneak current. The entire device fabrication was carried out using printing technology followed by encapsulation in an atomically thin layer of aluminum oxide (Al2O3) for protection against environmental humidity. The proposed memory device exhibited attractive bipolar switching characteristics of high switching ratio, large electrical endurance and enhanced lifetime, without any crosstalk between adjacent memory cells. The as-fabricated device showed excellent durability for several bending cycles at various bending diameters without any degradation in bistable resistive states. The memory mechanism was deduced to be conductive filamentary; this was validated by illustrating the temperature dependence of bistable resistive states. Our obtained results pave the way for the execution of promising 2D material based next generation flexible and non-volatile memory (NVM) applications.

Cotton fabric-based electrochemical device for lactate measurement in saliva.

PubMed

Malon, Radha S P; Chua, K Y; Wicaksono, Dedy H B; Córcoles, Emma P

2014-06-21

Lactate measurement is vital in clinical diagnostics especially among trauma and sepsis patients. In recent years, it has been shown that saliva samples are an excellent applicable alternative for non-invasive measurement of lactate. In this study, we describe a method for the determination of lactate concentration in saliva samples by using a simple and low-cost cotton fabric-based electrochemical device (FED). The device was fabricated using template method for patterning the electrodes and wax-patterning technique for creating the sample placement/reaction zone. Lactate oxidase (LOx) enzyme was immobilised at the reaction zone using a simple entrapment method. The LOx enzymatic reaction product, hydrogen peroxide (H2O2) was measured using chronoamperometric measurements at the optimal detection potential (-0.2 V vs. Ag/AgCl), in which the device exhibited a linear working range between 0.1 to 5 mM, sensitivity (slope) of 0.3169 μA mM(-1) and detection limit of 0.3 mM. The low detection limit and wide linear range were suitable to measure salivary lactate (SL) concentration, thus saliva samples obtained under fasting conditions and after meals were evaluated using the FED. The measured SL varied among subjects and increased after meals randomly. The proposed device provides a suitable analytical alternative for rapid and non-invasive determination of lactate in saliva samples. The device can also be adapted to a variety of other assays that requires simplicity, low-cost, portability and flexibility.

Method for integrating microelectromechanical devices with electronic circuitry

DOEpatents

Barron, Carole C.; Fleming, James G.; Montague, Stephen

1999-01-01

A method is disclosed for integrating one or more microelectromechanical (MEM) devices with electronic circuitry on a common substrate. The MEM device can be fabricated within a substrate cavity and encapsulated with a sacrificial material. This allows the MEM device to be annealed and the substrate planarized prior to forming electronic circuitry on the substrate using a series of standard processing steps. After fabrication of the electronic circuitry, the electronic circuitry can be protected by a two-ply protection layer of titanium nitride (TiN) and tungsten (W) during an etch release process whereby the MEM device is released for operation by etching away a portion of a sacrificial material (e.g. silicon dioxide or a silicate glass) that encapsulates the MEM device. The etch release process is preferably performed using a mixture of hydrofluoric acid (HF) and hydrochloric acid (HCI) which reduces the time for releasing the MEM device compared to use of a buffered oxide etchant. After release of the MEM device, the TiN:W protection layer can be removed with a peroxide-based etchant without damaging the electronic circuitry.

Microfabrication of plastic-PDMS microfluidic devices using polyimide release layer and selective adhesive bonding

DOE PAGES

Wang, Shuyu; Yu, Shifeng; Lu, Ming; ...

2017-03-15

In this study, we present an improved method to bond poly(dimethylsiloxane) (PDMS) with polyimide (PI) to develop flexible substrate microfluidic devices. The PI film was separately fabricated on a silicon wafer by spin coating followed by thermal treatment to avoid surface unevenness of the flexible substrate. In this way, we could also integrate flexible substrate into standard micro-electromechanical systems (MEMS) fabrication. Meanwhile, the adhesive epoxy was selectively transferred to the PDMS microfluidic device by a stamp-and-stick method to avoid epoxy clogging the microfluidic channels. To spread out the epoxy evenly on the transferring substrate, we used superhydrophilic vanadium oxide filmmore » coated glass as the transferring substrate. After the bonding process, the flexible substrate could easily be peeled off from the rigid substrate. Contact angle measurement was used to characterize the hydrophicity of the vanadium oxide film. X-ray photoelectron spectroscopy analysis was conducted to study the surface of the epoxy. We further evaluated the bonding quality by peeling tests, which showed a maximum bonding strength of 100 kPa. By injecting with black ink, the plastic microfluidic device was confirmed to be well bonded with no leakage for a day under 1 atm. Finally, this proposed versatile method could bond the microfluidic device and plastic substrate together and be applied in the fabrication of some biosensors and lab-on-a-chip systems.« less

Microfabrication of plastic-PDMS microfluidic devices using polyimide release layer and selective adhesive bonding

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

Wang, Shuyu; Yu, Shifeng; Lu, Ming

In this study, we present an improved method to bond poly(dimethylsiloxane) (PDMS) with polyimide (PI) to develop flexible substrate microfluidic devices. The PI film was separately fabricated on a silicon wafer by spin coating followed by thermal treatment to avoid surface unevenness of the flexible substrate. In this way, we could also integrate flexible substrate into standard micro-electromechanical systems (MEMS) fabrication. Meanwhile, the adhesive epoxy was selectively transferred to the PDMS microfluidic device by a stamp-and-stick method to avoid epoxy clogging the microfluidic channels. To spread out the epoxy evenly on the transferring substrate, we used superhydrophilic vanadium oxide filmmore » coated glass as the transferring substrate. After the bonding process, the flexible substrate could easily be peeled off from the rigid substrate. Contact angle measurement was used to characterize the hydrophicity of the vanadium oxide film. X-ray photoelectron spectroscopy analysis was conducted to study the surface of the epoxy. We further evaluated the bonding quality by peeling tests, which showed a maximum bonding strength of 100 kPa. By injecting with black ink, the plastic microfluidic device was confirmed to be well bonded with no leakage for a day under 1 atm. Finally, this proposed versatile method could bond the microfluidic device and plastic substrate together and be applied in the fabrication of some biosensors and lab-on-a-chip systems.« less

Method of forming crystalline silicon devices on glass

DOEpatents

McCarthy, A.M.

1995-03-21

A method is disclosed for fabricating single-crystal silicon microelectronic components on a silicon substrate and transferring same to a glass substrate. This is achieved by utilizing conventional silicon processing techniques for fabricating components of electronic circuits and devices on bulk silicon, wherein a bulk silicon surface is prepared with epitaxial layers prior to the conventional processing. The silicon substrate is bonded to a glass substrate and the bulk silicon is removed leaving the components intact on the glass substrate surface. Subsequent standard processing completes the device and circuit manufacturing. This invention is useful in applications requiring a transparent or insulating substrate, particularly for display manufacturing. Other applications include sensors, actuators, optoelectronics, radiation hard electronics, and high temperature electronics. 7 figures.

Single step sequential polydimethylsiloxane wet etching to fabricate a microfluidic channel with various cross-sectional geometries

NASA Astrophysics Data System (ADS)

Wang, C.-K.; Liao, W.-H.; Wu, H.-M.; Lo, Y.-H.; Lin, T.-R.; Tung, Y.-C.

2017-11-01

Polydimethylsiloxane (PDMS) has become a widely used material to construct microfluidic devices for various biomedical and chemical applications due to its desirable material properties and manufacturability. PDMS microfluidic devices are usually fabricated using soft lithography replica molding methods with master molds made of photolithogrpahy patterned photoresist layers on silicon wafers. The fabricated microfluidic channels often have rectangular cross-sectional geometries with single or multiple heights. In this paper, we develop a single step sequential PDMS wet etching process that can be used to fabricate microfluidic channels with various cross-sectional geometries from single-layer PDMS microfluidic channels. The cross-sections of the fabricated channel can be non-rectangular, and varied along the flow direction. Furthermore, the fabricated cross-sectional geometries can be numerically simulated beforehand. In the experiments, we fabricate microfluidic channels with various cross-sectional geometries using the developed technique. In addition, we fabricate a microfluidic mixer with alternative mirrored cross-sectional geometries along the flow direction to demonstrate the practical usage of the developed technique.

Method for making an electrochemical cell

DOEpatents

Tuller, Harry L.; Kramer, Steve A.; Spears, Marlene A.; Pal, Uday B.

1996-01-01

An electrochemical device including a solid electrolyte and solid electrode composed of materials having different chemical compositions and characterized by different electrical properties but having the same crystalline phase is provided. A method for fabricating an electrochemical device having a solid electrode and solid electrolyte characterized by the same crystalline phase is provided.

Poly(lactic-co-glycolic acid) devices: Production and applications for sustained protein delivery.

PubMed

Lee, Parker W; Pokorski, Jonathan K

2018-03-13

Injectable or implantable poly(lactic-co-glycolic acid) (PLGA) devices for the sustained delivery of proteins have been widely studied and utilized to overcome the necessity of repeated administrations for therapeutic proteins due to poor pharmacokinetic profiles of macromolecular therapies. These devices can come in the form of microparticles, implants, or patches depending on the disease state and route of administration. Furthermore, the release rate can be tuned from weeks to months by controlling the polymer composition, geometry of the device, or introducing additives during device fabrication. Slow-release devices have become a very powerful tool for modern medicine. Production of these devices has initially focused on emulsion-based methods, relying on phase separation to encapsulate proteins within polymeric microparticles. Process parameters and the effect of additives have been thoroughly researched to ensure protein stability during device manufacturing and to control the release profile. Continuous fluidic production methods have also been utilized to create protein-laden PLGA devices through spray drying and electrospray production. Thermal processing of PLGA with solid proteins is an emerging production method that allows for continuous, high-throughput manufacturing of PLGA/protein devices. Overall, polymeric materials for protein delivery remain an emerging field of research for the creation of single administration treatments for a wide variety of disease. This review describes, in detail, methods to make PLGA devices, comparing traditional emulsion-based methods to emerging methods to fabricate protein-laden devices. This article is categorized under: Biology-Inspired Nanomaterials > Protein and Virus-Based Structures Implantable Materials and Surgical Technologies > Nanomaterials and Implants Biology-Inspired Nanomaterials > Peptide-Based Structures. © 2018 Wiley Periodicals, Inc.

Vacuum-free laminated top electrode with conductive tapes for scalable manufacturing of efficient perovskite solar cells

DOE PAGES

Shao, Yuchuan; Wang, Qi; Dong, Qingfeng; ...

2015-06-25

The efficiency of organometal trihalide perovskites (OTP) solar cells have reached that parity of single crystal silicon, and its nature abundant raw material and solution-process capability promise a bright future for commercialization. However, the vacuum based techniques for metal electrode deposition and additional encapsulation layer increase the cost of the perovskite solar cells dramatically and impede their commercialization process. Here, we report a vacuum-free low temperature lamination technique to fabricate the top electrode by commercial conductive tapes (C-tape). The simple fabrication method yields good quality contact and high efficiency device of 12.7%. The C-tapes also encapsulated the devices effectively, resultingmore » in greatly improved device stability. As a result, the combination of lamination of electrodes and encapsulation layers into a single step significantly reduce the cost of device fabrication.« less

Carbon nanotube collimator fabrication and application

DOEpatents

Chow, Lee; Chai, Guangyu; Schenkel, Thomas

2010-07-06

Apparatus, methods, systems and devices for fabricating individual CNT collimators. Micron size fiber coated CNT samples are synthesized with chemical vapor deposition method and then the individual CNT collimators are fabricated with focused ion beam technique. Unfocused electron beams are successfully propagated through the CNT collimators. The CNT nano-collimators are used for applications including single ion implantation and in high-energy physics, and allow rapid, reliable testing of the transmission of CNT arrays for transport of molecules.

A rapid, straightforward, and print house compatible mass fabrication method for integrating 3D paper-based microfluidics.

PubMed

Xiao, Liangpin; Liu, Xianming; Zhong, Runtao; Zhang, Kaiqing; Zhang, Xiaodi; Zhou, Xiaomian; Lin, Bingcheng; Du, Yuguang

2013-11-01

Three-dimensional (3D) paper-based microfluidics, which is featured with high performance and speedy determination, promise to carry out multistep sample pretreatment and orderly chemical reaction, which have been used for medical diagnosis, cell culture, environment determination, and so on with broad market prospect. However, there are some drawbacks in the existing fabrication methods for 3D paper-based microfluidics, such as, cumbersome and time-consuming device assembly; expensive and difficult process for manufacture; contamination caused by organic reagents from their fabrication process. Here, we present a simple printing-bookbinding method for mass fabricating 3D paper-based microfluidics. This approach involves two main steps: (i) wax-printing, (ii) bookbinding. We tested the delivery capability, diffusion rate, homogeneity and demonstrated the applicability of the device to chemical analysis by nitrite colorimetric assays. The described method is rapid (<30 s), cheap, easy to manipulate, and compatible with the flat stitching method that is common in a print house, making itself an ideal scheme for large-scale production of 3D paper-based microfluidics. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multilevel metallization method for fabricating a metal oxide semiconductor device

NASA Technical Reports Server (NTRS)

Hollis, B. R., Jr.; Feltner, W. R.; Bouldin, D. L.; Routh, D. E. (Inventor)

1978-01-01

An improved method is described of constructing a metal oxide semiconductor device having multiple layers of metal deposited by dc magnetron sputtering at low dc voltages and low substrate temperatures. The method provides multilevel interconnections and cross over between individual circuit elements in integrated circuits without significantly reducing the reliability or seriously affecting the yield.

Integrating nanosphere lithography in device fabrication

NASA Astrophysics Data System (ADS)

Laurvick, Tod V.; Coutu, Ronald A.; Lake, Robert A.

2016-03-01

This paper discusses the integration of nanosphere lithography (NSL) with other fabrication techniques, allowing for nano-scaled features to be realized within larger microelectromechanical system (MEMS) based devices. Nanosphere self-patterning methods have been researched for over three decades, but typically not for use as a lithography process. Only recently has progress been made towards integrating many of the best practices from these publications and determining a process that yields large areas of coverage, with repeatability and enabled a process for precise placement of nanospheres relative to other features. Discussed are two of the more common self-patterning methods used in NSL (i.e. spin-coating and dip coating) as well as a more recently conceived variation of dip coating. Recent work has suggested the repeatability of any method depends on a number of variables, so to better understand how these variables affect the process a series of test vessels were developed and fabricated. Commercially available 3-D printing technology was used to incrementally alter the test vessels allowing for each variable to be investigated individually. With these deposition vessels, NSL can now be used in conjunction with other fabrication steps to integrate features otherwise unattainable through current methods, within the overall fabrication process of larger MEMS devices. Patterned regions in 1800 series photoresist with a thickness of ~700nm are used to capture regions of self-assembled nanospheres. These regions are roughly 2-5 microns in width, and are able to control the placement of 500nm polystyrene spheres by controlling where monolayer self-assembly occurs. The resulting combination of photoresist and nanospheres can then be used with traditional deposition or etch methods to utilize these fine scale features in the overall design.

Low-cost fabrication and performance testing of Polydimethylsiloxane (PDMS) micromixers using an improved print-and-Peel (PAP) method

NASA Astrophysics Data System (ADS)

Abagon, Ma. Victoria; Buendia, Neil Daniel; Jasper Caracas, Corine; July Yap, Kristian

2018-03-01

The research presents different configurations of microfluidic mixers made from polydimethylsiloxane (PDMS) fabricated using an improved, low-cost print-and-peel (PAP) method. Processes, such as mixing, operated in the micro scale allow decreased equipment size-to-production capacity ratio and decreased energy consumption per unit product. In the study, saturated solutions of blue and yellow food dyes were introduced inside the channels using a LEGO® improvised microsyringe pump. Scanning Electron Microscopy (SEM) was used to determine the average depth of the fabricated micromixers which was found to be around 14 ¼m. The flows were observed and images were taken using a light microscope. The color intensities of the images were then measured using MATLAB®. From the relationship between color intensity and concentration, the mixing indices were calculated and found to be 0.9435 to 0.9941, which falls within the standard mixing index range (0.8 - 1.0) regardless of the flow rate and the configuration of the micromixer as verified through the two-way ANOVA. From the cost analysis, the cost of the device fabricated in this study is a hundred-fold less than expenses from standard fabrication procedures. Hence, the fabricated device provides an alternative for micromixers produced from expensive and conventional lithographic methods.

Transparent and Flexible Supercapacitors with Networked Electrodes.

PubMed

Kiruthika, S; Sow, Chaitali; Kulkarni, G U

2017-10-01

Transparent and flexible energy storage devices have received immense attention due to their suitability for innovative electronics and displays. However, it remains a great challenge to fabricate devices with high storage capacity and high degree of transmittance. This study describes a simple process for fabrication of supercapacitors with ≈75% of visible transparency and areal capacitance of ≈3 mF cm -2 with high stability tested over 5000 cycles of charging and discharging. The electrodes consist of Au wire networks obtained by a simple crackle template method which are coated with MnO 2 nanostructures by electrodeposition process. Importantly, the membrane separator itself is employed as substrate to bring in the desired transparency and light weight while additionally exploiting its porous nature in enhancing the interaction of electrolyte with the active material from both sides of the substrate, thereby enhancing the storage capacity. The method opens up new ways for fabricating transparent devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lattice-mismatched GaInP LED devices and methods of fabricating same

DOEpatents

Mascarenhas, Angelo; Steiner, Myles A; Bhusal, Lekhnath; Zhang, Yong

2014-10-21

A method (100) of fabricating an LED or the active regions of an LED and an LED (200). The method includes growing, depositing or otherwise providing a bottom cladding layer (208) of a selected semiconductor alloy with an adjusted bandgap provided by intentionally disordering the structure of the cladding layer (208). A first active layer (202) may be grown above the bottom cladding layer (208) wherein the first active layer (202) is fabricated of the same semiconductor alloy, with however, a partially ordered structure. The first active layer (202) will also be fabricated to include a selected n or p type doping. The method further includes growing a second active layer (204) above the first active layer (202) where the second active layer (204) Is fabricated from the same semiconductor alloy.

Novel fabrication of flexible graphene-based chemical sensors with heaters using soft lithographic patterning method.

PubMed

Jung, Min Wook; Myung, Sung; Song, Wooseok; Kang, Min-A; Kim, Sung Ho; Yang, Cheol-Soo; Lee, Sun Sook; Lim, Jongsun; Park, Chong-Yun; Lee, Jeong-O; An, Ki-Seok

2014-08-27

We have fabricated graphene-based chemical sensors with flexible heaters for the highly sensitive detection of specific gases. We believe that increasing the temperature of the graphene surface significantly enhanced the electrical signal change of the graphene-based channel, and reduced the recovery time needed to obtain a normal state of equilibrium. In addition, a simple and efficient soft lithographic patterning process was developed via surface energy modification for advanced, graphene-based flexible devices, such as gas sensors. As a proof of concept, we demonstrated the high sensitivity of NO2 gas sensors based on graphene nanosheets. These devices were fabricated using a simple soft-lithographic patterning method, where flexible graphene heaters adjacent to the channel of sensing graphene were utilized to control graphene temperature.

A novel fabrication method for suspended high-aspect-ratio microstructures

NASA Astrophysics Data System (ADS)

Yang, Yao-Joe; Kuo, Wen-Cheng

2005-11-01

Suspended high-aspect-ratio structures (suspended HARS) are widely used for MEMS devices such as micro-gyroscopes, micro-accelerometers, optical switches and so on. Various fabrication methods, such as SOI, SCREAM, AIM, SBM and BELST processes, were proposed to fabricate HARS. However, these methods focus on the fabrication of suspended microstructures with relatively small widths of trench opening (e.g. less than 10 µm). In this paper, we propose a novel process for fabricating very high-aspect-ratio suspended structures with large widths of trench opening using photoresist as an etching mask. By enhancing the microtrenching effect, we can easily release the suspended structure without thoroughly removing the floor polymer inside the trenches for the cases with a relatively small trench aspect ratio. All the process steps can be integrated into a single-run single-mask ICP-RIE process, which effectively reduces the process complexity and fabrication cost. We also discuss the phenomenon of corner erosion, which results in the undesired etching of silicon structures during the structure-releasing step. By using the proposed process, 100 µm thick suspended structures with the trench aspect ratio of about 20 are demonstrated. Also, the proposed process can be used to fabricate devices for applications which require large in-plane displacement. This paper was orally presented in the Transducers'05, Seoul, Korea (paper ID: 3B1.3).

Thermoplastic microfluidic devices and their applications in protein and DNA analysis

PubMed Central

Liu, Ke; Fan, Z. Hugh

2013-01-01

Microfluidics is a platform technology that has been used for genomics, proteomics, chemical synthesis, environment monitoring, cellular studies, and other applications. The fabrication materials of microfluidic devices have traditionally included silicon and glass, but plastics have gained increasing attention in the past few years. We focus this review on thermoplastic microfluidic devices and their applications in protein and DNA analysis. We outline the device design and fabrication methods, followed by discussion on the strategies of surface treatment. We then concentrate on several significant advancements in applying thermoplastic microfluidic devices to protein separation, immunoassays, and DNA analysis. Comparison among numerous efforts, as well as the discussion on the challenges and innovation associated with detection, is presented. PMID:21274478

Integrated Flexible Electronic Devices Based on Passive Alignment for Physiological Measurement

PubMed Central

Ryu, Jin Hwa; Byun, Sangwon; Baek, In-Bok; Lee, Bong Kuk; Jang, Won Ick; Jang, Eun-Hye; Kim, Ah-Yung; Yu, Han Yung

2017-01-01

This study proposes a simple method of fabricating flexible electronic devices using a metal template for passive alignment between chip components and an interconnect layer, which enabled efficient alignment with high accuracy. An electrocardiogram (ECG) sensor was fabricated using 20 µm thick polyimide (PI) film as a flexible substrate to demonstrate the feasibility of the proposed method. The interconnect layer was fabricated by a two-step photolithography process and evaporation. After applying solder paste, the metal template was placed on top of the interconnect layer. The metal template had rectangular holes at the same position as the chip components on the interconnect layer. Rectangular hole sizes were designed to account for alignment tolerance of the chips. Passive alignment was performed by simply inserting the components in the holes of the template, which resulted in accurate alignment with positional tolerance of less than 10 µm based on the structural design, suggesting that our method can efficiently perform chip mounting with precision. Furthermore, a fabricated flexible ECG sensor was easily attachable to the curved skin surface and able to measure ECG signals from a human subject. These results suggest that the proposed method can be used to fabricate epidermal sensors, which are mounted on the skin to measure various physiological signals. PMID:28420219

Monolayer Transition Metal Dichalcogenides as Light Sources.

PubMed

Pu, Jiang; Takenobu, Taishi

2018-06-13

Reducing the dimensions of materials is one of the key approaches to discovering novel optical phenomena. The recent emergence of 2D transition metal dichalcogenides (TMDCs) has provided a promising platform for exploring new optoelectronic device applications, with their tunable electronic properties, structural controllability, and unique spin valley-coupled systems. This progress report provides an overview of recent advances in TMDC-based light-emitting devices discussed from several aspects in terms of device concepts, material designs, device fabrication, and their diverse functionalities. First, the advantages of TMDCs used in light-emitting devices and their possible functionalities are presented. Second, conventional approaches for fabricating TMDC light-emitting devices are emphasized, followed by introducing a newly established, versatile method for generating light emission in TMDCs. Third, current growing technologies for heterostructure fabrication, in which distinct TMDCs are vertically stacked or laterally stitched, are explained as a possible means for designing high-performance light-emitting devices. Finally, utilizing the topological features of TMDCs, the challenges for controlling circularly polarized light emission and its device applications are discussed from both theoretical and experimental points of view. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CVD Polymers for Devices and Device Fabrication.

PubMed

Wang, Minghui; Wang, Xiaoxue; Moni, Priya; Liu, Andong; Kim, Do Han; Jo, Won Jun; Sojoudi, Hossein; Gleason, Karen K

2017-03-01

Chemical vapor deposition (CVD) polymerization directly synthesizes organic thin films on a substrate from vapor phase reactants. Dielectric, semiconducting, electrically conducting, and ionically conducting CVD polymers have all been readily integrated into devices. The absence of solvent in the CVD process enables the growth of high-purity layers and avoids the potential of dewetting phenomena, which lead to pinhole defects. By limiting contaminants and defects, ultrathin (<10 nm) CVD polymeric device layers have been fabricated in multiple laboratories. The CVD method is particularly suitable for synthesizing insoluble conductive polymers, layers with high densities of organic functional groups, and robust crosslinked networks. Additionally, CVD polymers are prized for the ability to conformally cover rough surfaces, like those of paper and textile substrates, as well as the complex geometries of micro- and nanostructured devices. By employing low processing temperatures, CVD polymerization avoids damaging substrates and underlying device layers. This report discusses the mechanisms of the major CVD polymerization techniques and the recent progress of their applications in devices and device fabrication, with emphasis on initiated CVD (iCVD) and oxidative CVD (oCVD) polymerization. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Laser direct-write for fabrication of three-dimensional paper-based devices.

PubMed

He, P J W; Katis, I N; Eason, R W; Sones, C L

2016-08-16

We report the use of a laser-based direct-write (LDW) technique that allows the design and fabrication of three-dimensional (3D) structures within a paper substrate that enables implementation of multi-step analytical assays via a 3D protocol. The technique is based on laser-induced photo-polymerisation, and through adjustment of the laser writing parameters such as the laser power and scan speed we can control the depths of hydrophobic barriers that are formed within a substrate which, when carefully designed and integrated, produce 3D flow paths. So far, we have successfully used this depth-variable patterning protocol for stacking and sealing of multi-layer substrates, for assembly of backing layers for two-dimensional (2D) lateral flow devices and finally for fabrication of 3D devices. Since the 3D flow paths can also be formed via a single laser-writing process by controlling the patterning parameters, this is a distinct improvement over other methods that require multiple complicated and repetitive assembly procedures. This technique is therefore suitable for cheap, rapid and large-scale fabrication of 3D paper-based microfluidic devices.

A single blue nanorod light emitting diode.

PubMed

Hou, Y; Bai, J; Smith, R; Wang, T

2016-05-20

We report a light emitting diode (LED) consisting of a single InGaN/GaN nanorod fabricated by a cost-effective top-down approach from a standard LED wafer. The device demonstrates high performance with a reduced quantum confined Stark effect compared with a standard planar counterpart fabricated from the same wafer, confirmed by optical and electrical characterization. Current density as high as 5414 A cm(-2) is achieved without significant damage to the device due to the high internal quantum efficiency. The efficiency droop is mainly ascribed to Auger recombination, which was studied by an ABC model. Our work provides a potential method for fabricating compact light sources for advanced photonic integrated circuits without involving expensive or time-consuming fabrication facilities.

Microwave Assisted Synthesis of Porous NiCo2O4 Microspheres: Application as High Performance Asymmetric and Symmetric Supercapacitors with Large Areal Capacitance

PubMed Central

Khalid, Syed; Cao, Chuanbao; Wang, Lin; Zhu, Youqi

2016-01-01

Large areal capacitance is essentially required to integrate the energy storage devices at the microscale electronic appliances. Energy storage devices based on metal oxides are mostly fabricated with low mass loading per unit area which demonstrated low areal capacitance. It is still a challenge to fabricate supercapacitor devices of porous metal oxides with large areal capacitance. Herein we report microwave method followed by a pyrolysis of the as-prepared precursor is used to synthesize porous nickel cobaltite microspheres. Porous NiCo2O4 microspheres are capable to deliver large areal capacitance due to their high specific surface area and small crystallite size. The facile strategy is successfully demonstrated to fabricate aqueous-based asymmetric & symmetric supercapacitor devices of porous NiCo2O4 microspheres with high mass loading of electroactive materials. The asymmetric & symmetric devices exhibit maximum areal capacitance and energy density of 380 mF cm−2 & 19.1 Wh Kg−1 and 194 mF cm−2 & 4.5 Wh Kg−1 (based on total mass loading of 6.25 & 6.0 mg) respectively at current density of 1 mA cm−2. The successful fabrication of symmetric device also indicates that NiCo2O4 can also be used as the negative electrode material for futuristic asymmetric devices. PMID:26936283

Microwave Assisted Synthesis of Porous NiCo2O4 Microspheres: Application as High Performance Asymmetric and Symmetric Supercapacitors with Large Areal Capacitance

NASA Astrophysics Data System (ADS)

Khalid, Syed; Cao, Chuanbao; Wang, Lin; Zhu, Youqi

2016-03-01

Large areal capacitance is essentially required to integrate the energy storage devices at the microscale electronic appliances. Energy storage devices based on metal oxides are mostly fabricated with low mass loading per unit area which demonstrated low areal capacitance. It is still a challenge to fabricate supercapacitor devices of porous metal oxides with large areal capacitance. Herein we report microwave method followed by a pyrolysis of the as-prepared precursor is used to synthesize porous nickel cobaltite microspheres. Porous NiCo2O4 microspheres are capable to deliver large areal capacitance due to their high specific surface area and small crystallite size. The facile strategy is successfully demonstrated to fabricate aqueous-based asymmetric & symmetric supercapacitor devices of porous NiCo2O4 microspheres with high mass loading of electroactive materials. The asymmetric & symmetric devices exhibit maximum areal capacitance and energy density of 380 mF cm-2 & 19.1 Wh Kg-1 and 194 mF cm-2 & 4.5 Wh Kg-1 (based on total mass loading of 6.25 & 6.0 mg) respectively at current density of 1 mA cm-2. The successful fabrication of symmetric device also indicates that NiCo2O4 can also be used as the negative electrode material for futuristic asymmetric devices.

In-chip microstructures and photonic devices fabricated by nonlinear laser lithography deep inside silicon

PubMed Central

Makey, Ghaith; Elahi, Parviz; Çolakoğlu, Tahir; Ergeçen, Emre; Yavuz, Özgün; Hübner, René; Borra, Mona Zolfaghari; Pavlov, Ihor; Bek, Alpan; Turan, Raşit; Kesim, Denizhan Koray; Tozburun, Serhat; Ilday, Serim; Ilday, F. Ömer

2017-01-01

Silicon is an excellent material for microelectronics and integrated photonics1–3 with untapped potential for mid-IR optics4. Despite broad recognition of the importance of the third dimension5,6, current lithography methods do not allow fabrication of photonic devices and functional microelements directly inside silicon chips. Even relatively simple curved geometries cannot be realised with techniques like reactive ion etching. Embedded optical elements, like in glass7, electronic devices, and better electronic-photonic integration are lacking8. Here, we demonstrate laser-based fabrication of complex 3D structures deep inside silicon using 1 µm-sized dots and rod-like structures of adjustable length as basic building blocks. The laser-modified Si has a different optical index than unmodified parts, which enables numerous photonic devices. Optionally, these parts are chemically etched to produce desired 3D shapes. We exemplify a plethora of subsurface, i.e., “in-chip” microstructures for microfluidic cooling of chips, vias, MEMS, photovoltaic applications and photonic devices that match or surpass the corresponding state-of-the-art device performances. PMID:28983323

In-chip microstructures and photonic devices fabricated by nonlinear laser lithography deep inside silicon

NASA Astrophysics Data System (ADS)

Tokel, Onur; Turnalı, Ahmet; Makey, Ghaith; Elahi, Parviz; ćolakoǧlu, Tahir; Ergeçen, Emre; Yavuz, Ã.-zgün; Hübner, René; Zolfaghari Borra, Mona; Pavlov, Ihor; Bek, Alpan; Turan, Raşit; Kesim, Denizhan Koray; Tozburun, Serhat; Ilday, Serim; Ilday, F. Ã.-mer

2017-10-01

Silicon is an excellent material for microelectronics and integrated photonics1-3, with untapped potential for mid-infrared optics4. Despite broad recognition of the importance of the third dimension5,6, current lithography methods do not allow the fabrication of photonic devices and functional microelements directly inside silicon chips. Even relatively simple curved geometries cannot be realized with techniques like reactive ion etching. Embedded optical elements7, electronic devices and better electronic-photonic integration are lacking8. Here, we demonstrate laser-based fabrication of complex 3D structures deep inside silicon using 1-µm-sized dots and rod-like structures of adjustable length as basic building blocks. The laser-modified Si has an optical index different to that in unmodified parts, enabling the creation of numerous photonic devices. Optionally, these parts can be chemically etched to produce desired 3D shapes. We exemplify a plethora of subsurface—that is, `in-chip'—microstructures for microfluidic cooling of chips, vias, micro-electro-mechanical systems, photovoltaic applications and photonic devices that match or surpass corresponding state-of-the-art device performances.

High Performance MgO-barrier Magnetic Tunnel Junctions for Flexible and Wearable Spintronic Applications.

PubMed

Chen, Jun-Yang; Lau, Yong-Chang; Coey, J M D; Li, Mo; Wang, Jian-Ping

2017-02-02

The magnetic tunnel junction (MTJ) using MgO barrier is one of most important building blocks for spintronic devices and has been widely utilized as miniaturized magentic sensors. It could play an important role in wearable medical devices if they can be fabricated on flexible substrates. The required stringent fabrication processes to obtain high quality MgO-barrier MTJs, however, limit its integration with flexible electronics devices. In this work, we have developed a method to fabricate high-performance MgO-barrier MTJs directly onto ultrathin flexible silicon membrane with a thickness of 14 μm and then transfer-and-bond to plastic substrates. Remarkably, such flexible MTJs are fully functional, exhibiting a TMR ratio as high as 190% under bending radii as small as 5 mm. The devices' robustness is manifested by its retained excellent performance and unaltered TMR ratio after over 1000 bending cycles. The demonstrated flexible MgO-barrier MTJs opens the door to integrating high-performance spintronic devices in flexible and wearable electronics devices for a plethora of biomedical sensing applications.

Flexible Nanowire Cluster as a Wearable Colorimetric Humidity Sensor.

PubMed

Wei, Zhiqiang; Zhou, Zhang-Kai; Li, Qiuyu; Xue, Jiancai; Di Falco, Andrea; Yang, Zhongjian; Zhou, Jianhua; Wang, Xuehua

2017-07-01

Wearable plasmonic devices combine the advantages of high flexibility, ultrathinness, light weight, and excellent integration with the optical benefits mediated by plasmon-enhanced electric fields. However, two obstacles severely hinder further developments and applications of a wearable plasmonic device. One is the lack of efficient approach to obtaining devices with robust antimotion-interference property, i.e., the devices can work independently on the morphology changes of their working structures caused by arbitrary wearing conditions. The other issue is to seek a facile and high-throughput fabrication method to satisfy the financial requirement of industrialization. In order to overcome these two challenges, a functional flexible film of nanowire cluster is developed, which can be easily fabricated by taking the advantages of both conventional electrochemical and sputtering methods. Such flexible plasmonic films can be made into wearable devices that work independently on shape changes induced by various wearing conditions (such as bending, twisting and stretching). Furthermore, due to plasmonic advantages of color controlling and high sensitivity to environment changes, the flexible film of nanowire cluster can be used to fabricate wearable items (such as bracelet, clothes, bag, or even commercial markers), with the ability of wireless visualization for humidity sensing. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhanced performance of wearable piezoelectric nanogenerator fabricated by two-step hydrothermal process

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

Qiu, Yu; Lei, Jixue; Yin, Bing

2014-03-17

A simple two-step hydrothermal process was proposed for enhancing the performance of the nanogenerator on flexible and wearable terylene-fabric substrate. With this method, a significant enhancement in output voltage of the nanogenerator from ∼10 mV to 7 V was achieved, comparing with the one by conventional one-step process. In addition, another advantage with the devices synthesized by two-step hydrothermal process was that their output voltages are only sensitive to strain rather than strain rate. The devices with a high output voltage have the ability to power common electric devices and will have important applications in flexible electronics and wearable devices.

Finger-triggered portable PDMS suction cup for equipment-free microfluidic pumping

NASA Astrophysics Data System (ADS)

Lee, Sanghyun; Kim, Hojin; Lee, Wonhyung; Kim, Joonwon

2018-12-01

This study presents a finger-triggered portable polydimethylsiloxane suction cup that enables equipment-free microfluidic pumping. The key feature of this method is that its operation only involves a "pressing-and-releasing" action for the cup placed at the outlet of a microfluidic device, which transports the fluid at the inlet toward the outlet through a microchannel. This method is simple, but effective and powerful. The cup is portable and can easily be fabricated from a three-dimensional printed mold, used without any pre-treatment, reversibly bonded to microfluidic devices without leakage, and applied to various material-based microfluidic devices. The effect of the suction cup geometry and fabrication conditions on the pumping performance was investigated. Furthermore, we demonstrated the practical applications of the suction cup by conducting an equipment-free pumping of thermoplastic-based microfluidic devices and water-in-oil droplet generation.

Hetero-junction photovoltaic device and method of fabricating the device

DOEpatents

Aytug, Tolga; Christen, David K; Paranthaman, Mariappan Parans; Polat, Ozgur

2014-02-10

A hetero-junction device and fabrication method in which phase-separated n-type and p-type semiconductor pillars define vertically-oriented p-n junctions extending above a substrate. Semiconductor materials are selected for the p-type and n-type pillars that are thermodynamically stable and substantially insoluble in one another. An epitaxial deposition process is employed to form the pillars on a nucleation layer and the mutual insolubility drives phase separation of the materials. During the epitaxial deposition process, the orientation is such that the nucleation layer initiates propagation of vertical columns resulting in a substantially ordered, three-dimensional structure throughout the deposited material. An oxidation state of at least a portion of one of the p-type or the n-type semiconductor materials is altered relative to the other, such that the band-gap energy of the semiconductor materials differ with respect to stoichiometric compositions and the device preferentially absorbs particular selected bands of radiation.

Fabrication of Gold-coated 3-D Woodpile Structures for Mid-IR Thermal Emitters

NASA Astrophysics Data System (ADS)

Li, Shengkai; Moridani, Amir; Kothari, Rohit; Lee, Jae-Hwang; Watkins, James

3-D metallic woodpile nanostructures possess enhancements in thermal radiation that are both wavelength and polarization specific and are promising for thermal-optical devices for various applications including thermal photovoltaics, self-cooling devices, and chemical and bio-sensors. However, current fabrication techniques for such structures are limited by slow speed, small area capability, the need for expensive facilities and, in general, are not suitable for high-throughput mass production. Here we demonstrate a new strategy for the fabrication of 3D metallic woodpile structures. Well-defined TiO2 woodpile structures were fabricated using a layer-by-layer nanoimprint method using TiO2 nanoparticle ink dispersions. The TiO2 woodpile was then coated with a high purity, conformal gold film via reactive deposition in supercritical carbon dioxide. The final gold-coated woodpile structures exhibit strong spectral and polarization specific thermal emission enhancements. The fabrication method demonstrated here is promising for high-throughput, low-cost preparation of 3D metallic woodpile structures and other 3D nanostructures. Center for Hierarchical Manufacturing, NSF.

The fabrication of ZnO nanowire field-effect transistors by roll-transfer printing

NASA Astrophysics Data System (ADS)

Chang, Yi-Kuei; Hong, Franklin Chau-Nan

2009-05-01

A method with the potential to fabricate large-area nanowire field-effect transistors (NW-FETs) was demonstrated in this study. Using a high-speed roller (20-80 cm min-1), transfer printing was successfully employed to transfer vertically aligned zinc oxide (ZnO) nanowires grown on a donor substrate to a polydimethylsiloxane (PDMS) stamp and then print the ordered ZnO nanowire arrays on the received substrate for the fabrication of NW-FETs. ZnO NW-FETs fabricated by this method exhibit high performances with a threshold voltage of around 0.25 V, a current on/off ratio as high as 105, a subthreshold slope of 360 mV/dec, and a field-effect mobility of around 90 cm2 V-1 s-1. The excellent device characteristics suggest that the roll-transfer printing technique, which is compatible with the roll-to-roll (R2R) process and operated in atmosphere, has a good potential for the high-speed fabrication of large-area nanowire transistors for flexible devices and flat panel displays.

The fabrication of ZnO nanowire field-effect transistors by roll-transfer printing.

PubMed

Chang, Yi-Kuei; Hong, Franklin Chau-Nan

2009-05-13

A method with the potential to fabricate large-area nanowire field-effect transistors (NW-FETs) was demonstrated in this study. Using a high-speed roller (20-80 cm min(-1)), transfer printing was successfully employed to transfer vertically aligned zinc oxide (ZnO) nanowires grown on a donor substrate to a polydimethylsiloxane (PDMS) stamp and then print the ordered ZnO nanowire arrays on the received substrate for the fabrication of NW-FETs. ZnO NW-FETs fabricated by this method exhibit high performances with a threshold voltage of around 0.25 V, a current on/off ratio as high as 10(5), a subthreshold slope of 360 mV/dec, and a field-effect mobility of around 90 cm(2) V(-1) s(-1). The excellent device characteristics suggest that the roll-transfer printing technique, which is compatible with the roll-to-roll (R2R) process and operated in atmosphere, has a good potential for the high-speed fabrication of large-area nanowire transistors for flexible devices and flat panel displays.

Evaluation of a Low-Cost Commercially Available Extraction Device for Assessing Lead Bioaccessibility in Contaminated Soils

EPA Science Inventory

The U.S. EPA’s in vitro bioaccessibility (IVBA) method 9200.1-86 defines a validated analytical procedure for the determination of lead bioaccessibility in contaminated soils. The method requires the use of a custom-fabricated extraction device that uses a heated water bath for ...

Fabrication and optically pumped lasing of plasmonic nanolaser with regular ZnO/GaN nanoheterojunction array

NASA Astrophysics Data System (ADS)

Huang, Xiaoping; Zhang, Peifeng; Lin, En; Wang, Peng; Mei, Mingwei; Huang, Qiuying; Jiao, Jiao; Zhao, Qing

2017-09-01

We present the design and fabrication of a novel regularly arrayed plasmonic nanolasers. This main microstructure of the device is composed of a hexagonal array of n-ZnO/p-GaN nanoheterojunctions fabricated using the micro-fabrication method. Furthermore, the optically pumped lasing in the device is demonstrated. The spectroscopy characterization results of the device show that the surface plasmon excited around the NWs surface can be used to stimulate and strongly compress the optical modes in the NW cavity. This electromagnetic confinement effect is employed to optimize the beam quality and increase the light intensity compared to the laser fabricated with the bare NWs array. The impact of the array arrangement on the coherent combining efficiency of the arrayed nanolasers has been numerically studied. The results show that the arrayed hexagonal nanolasers could improve the combining efficiency compared to the nanolaser with the randomly positioned array. Qualitatively, these calculated results agree well with the experimental results of the laser beam spot mapping. This demonstrates the scope for using such architectures to improve the combination efficiency of the arrayed nanolasers.

Highly Stretchable Multifunctional Wearable Devices Based on Conductive Cotton and Wool Fabrics.

PubMed

Souri, Hamid; Bhattacharyya, Debes

2018-06-05

The demand for stretchable, flexible, and wearable multifunctional devices based on conductive nanomaterials is rapidly increasing considering their interesting applications including human motion detection, robotics, and human-machine interface. There still exists a great challenge to manufacture stretchable, flexible, and wearable devices through a scalable and cost-effective fabrication method. Herein, we report a simple method for the mass production of electrically conductive textiles, made of cotton and wool, by hybridization of graphene nanoplatelets and carbon black particles. Conductive textiles incorporated into a highly elastic elastomer are utilized as highly stretchable and wearable strain sensors and heaters. The electromechanical characterizations of our multifunctional devices establish their excellent performance as wearable strain sensors to monitor various human motions, such as finger, wrist, and knee joint movements, and to recognize sound with high durability. Furthermore, the electrothermal behavior of our devices shows their potential application as stretchable and wearable heaters working at a maximum temperature of 103 °C powered with 20 V.

Effects of Pretreatment on the Electronic Properties of Plasma Enhanced Chemical Vapor Deposition Hetero-Epitaxial Graphene Devices

NASA Astrophysics Data System (ADS)

Zhang, Lian-Chang; Shi, Zhi-Wen; Yang, Rong; Huang, Jian

2014-09-01

Quasi-monolayer graphene is successfully grown by the plasma enhanced chemical vapor deposition heteroepitaxial method we reported previously. To measure its electrical properties, the prepared graphene is fabricated into Hall ball shaped devices by the routine micro-fabrication method. However, impurity molecules adsorbed onto the graphene surface will impose considerable doping effects on the one-atom-thick film material. Our experiment demonstrates that pretreatment of the device by heat radiation baking and electrical annealing can dramatically influence the doping state of the graphene and consequently modify the electrical properties. While graphene in the as-fabricated device is highly p-doped, as confirmed by the position of the Dirac point at far more than +60 V, baking treatment at temperatures around 180°C can significantly lower the doping level and reduce the conductivity. The following electrical annealing is much more efficient to desorb the extrinsic molecules, as confirmed by the in situ measurement, and as a result, further modify the doping state and electrical properties of the graphene, causing a considerable drop of the conductivity and a shifting of Dirac point from beyond +60 V to 0 V.

Post-patterning of an electronic homojunction in atomically thin monoclinic MoTe2

NASA Astrophysics Data System (ADS)

Kim, Sera; Kim, Jung Ho; Kim, Dohyun; Hwang, Geunwoo; Baik, Jaeyoon; Yang, Heejun; Cho, Suyeon

2017-06-01

Monoclinic group 6 transition metal dichalcogenides (TMDs) have been extensively studied for their intriguing 2D physics (e.g. spin Hall insulator) as well as for ohmic homojunction contacts in 2D device applications. A critical prerequisite for those applications is thickness control of the monoclinic 2D materials, which allows subtle engineering of the topological states or electronic bandgaps. Local thickness control enables the realization of clean homojunctions between different electronic states, and novel device operation in a single material. However, conventional fabrication processes, including chemical methods, typically produce non-homogeneous and relatively thick monoclinic TMDs, due to their distorted octahedral structures. Here, we report on a post-patterning technique using laser-irradiation to fabricate homojunctions between two different thickness areas in monoclinic MoTe2. A thickness-dependent electronic change from a metallic to semiconducting state, resulting in an electronic homojunction, was realized by the optical patterning of pristine MoTe2 flakes, and a pre-patterned device channel of monoclinic MoTe2 with a thickness-resolution of 5 nm. Our work provides insight on an optical post-process method for controlling thickness, as a promising approach for fabricating impurity-free 2D TMDs homojunction devices.

Wideband monolithically integrated front-end subsystems and components

NASA Astrophysics Data System (ADS)

Mruk, Joseph Rene

This thesis presents the analysis, design, and measurements of passive, monolithically integrated, wideband recta-coax and printed circuit board front-end components. Monolithic fabrication of antennas, impedance transformers, filters, and transitions lowers manufacturing costs by reducing assembly time and enhances performance by removing connectors and cabling between the devices. Computational design, fabrication, and measurements are used to demonstrate the capabilities of these front-end assemblies. Two-arm wideband planar log-periodic antennas fed using a horizontal feed that allows for filters and impedance transformers to be readily fabricated within the radiating region of the antenna are demonstrated. At microwave frequencies, low-cost printed circuit board processes are typically used to produce planar devices. A 1.8 to 11 GHz two-arm planar log-periodic antenna is designed with a monolithically integrated impedance transformer. Band rejection methods based on modifying the antenna aperture, use of an integrated filter, and the application of both methods are investigated with realized gain suppressions of over 25 dB achieved. The ability of standard circuit board technology to fabricate millimeter-wave devices up to 110 GHz is severely limited. Thin dielectrics are required to prevent the excitation of higher order modes in the microstrip substrate. Fabricating the thin line widths required for the antenna aperture also becomes prohibitively challenging. Surface micro-machining typically used in the fabrication of MEMS devices is capable of producing the extremely small features that can be used to fabricate antennas extending through W-band. A directly RF fed 18 to 110 GHz planar log-periodic antenna is developed. The antenna is fabricated with an integrated impedance transformer and additional transitions for measurement characterization. Singly terminated low-loss wideband millimeter-wave filters operating over V- and W- band are developed. High quality performance of an 18 to 100 GHz front-end is realized by dividing the single instantaneous antenna into two apertures operating from 18 to 50 and 50 to 100 GHz. Each channel features an impedance transformer, low-pass (low-frequency) or band-pass (high-frequency) filter, and grounded CPW launch. This dual-aperture front-end demonstrates that micromachining technology is now capable of fabricating broadband millimeter-wave components with a high degree of integration.

CMOS compatible thin-film ALD tungsten nanoelectromechanical devices

NASA Astrophysics Data System (ADS)

Davidson, Bradley Darren

This research focuses on the development of a novel, low-temperature, CMOS compatible, atomic-layer-deposition (ALD) enabled NEMS fabrication process for the development of ALD Tungsten (WALD) NEMS devices. The devices are intended for use in CMOS/NEMS hybrid systems, and NEMS based micro-processors/controllers capable of reliable operation in harsh environments not accessible to standard CMOS technologies. The majority of NEMS switches/devices to date have been based on carbon-nano-tube (CNT) designs. The devices consume little power during actuation, and as expected, have demonstrated actuation voltages much smaller than MEMS switches. Unfortunately, NEMS CNT switches are not typically CMOS integrable due to the high temperatures required for their growth, and their fabrication typically results in extremely low and unpredictable yields. Thin-film NEMS devices offer great advantages over reported CNT devices for several reasons, including: higher fabrication yields, low-temperature (CMOS compatible) deposition techniques like ALD, and increased control over design parameters/device performance metrics, i.e., device geometry. Furthermore, top-down, thin-film, nano-fabrication techniques are better capable of producing complicated device geometries than CNT based processes, enabling the design and development of multi-terminal switches well-suited for low-power hybrid NEMS/CMOS systems as well as electromechanical transistors and logic devices for use in temperature/radiation hard computing architectures. In this work several novel, low-temperature, CMOS compatible fabrication technologies, employing WALD as a structural layer for MEMS or NEMS devices, were developed. The technologies developed are top-down nano-scale fabrication processes based on traditional micro-machining techniques commonly used in the fabrication of MEMS devices. Using these processes a variety of novel WALD NEMS devices have been successfully fabricated and characterized. Using two different WALD fabrication technologies two generations of 2-terminal WALD NEMS switches have been developed. These devices have functional gap heights of 30-50 nm, and actuation voltages typically ranging from 3--5 Volts. Via the extension of a two terminal WALD technology novel 3-terminal WALD NEMS devices were developed. These devices have actuation voltages ranging from 1.5--3 Volts, reliabilities in excess of 2 million cycles, and have been designed to be the fundamental building blocks for WALD NEMS complementary inverters. Through the development of these devices several advancements in the modeling and design of thin-film NEMS devices were achieved. A new model was developed to better characterize pre-actuation currents commonly measured for NEMS switches with nano-scale gate-to-source gap heights. The developed model is an extension of the standard field-emission model and considers the electromechanical response, and electric field effects specific to thin-film NEMS switches. Finally, a multi-physics FEM/FD based model was developed to simulate the dynamic behavior of 2 or 3-terminal electrostatically actuated devices whose electrostatic domains have an aspect ratio on the order of 10-3. The model uses a faux-Lagrangian finite difference method to solve Laplaces equation in a quasi-statatically deforming domain. This model allows for the numerical characterization and design of thin-film NEMS devices not feasible using typical non-specialized BEM/FEM based software. Using this model several novel and feasible designs for fixed-fixed 3-terminal WALD NEMS switches capable for the construction of complementary inverters were discovered.

Fast and Scalable Fabrication of Microscopic Optical Surfaces and its Application for Optical Interconnect Devices

NASA Astrophysics Data System (ADS)

Summitt, Christopher Ryan

The use of optical interconnects is a promising solution to the increasing demand for high speed mass data transmission used in integrated circuits as well as device to device data transfer applications. For the purpose, low cost polymer waveguides are a popular choice for routing signal between devices due to their compatibility with printed circuit boards. In optical interconnect, coupling from an external light source to such waveguides is a critical step, thus a variety of couplers have been investigated such as grating based couplers [1,2], evanescent couplers [3], and embedded mirrors [4-6]. These couplers are inherently micro-optical components which require fast and scalable fabrication for mass production with optical quality surfaces/structures. Low NA laser direct writing has been used for fast fabrication of structures such as gratings and Fresnel lenses using a linear laser direct writing scheme, though the length scale of such structures are an order of magnitude larger than the spot size of the focused laser of the tool. Nonlinear writing techniques such as with 2-photon absorption offer increased write resolution which makes it possible to fabricate sub-wavelength structures as well as having a flexibility in feature shape. However it does not allow a high speed fabrication and in general are not scalable due to limitations of speed and area induced by the tool's high NA optics. To overcome such limitations primarily imposed by NA, we propose a new micro-optic fabrication process which extends the capabilities of 1D, low NA, and thus fast and scalable, laser direct writing to fabricate a structure having a length scale close to the tool's spot size, for example, a mirror based and 45 degree optical coupler with optical surface quality. The newly developed process allows a high speed fabrication with a write speed of 2600 mm²/min by incorporating a mask based lithography method providing a blank structure which is critical to creating a 45 degree slope to form the coupler surface. In this method, instead of using an entire exposure in a pixelated manner, only a portion of the Gaussian profile is used, allowing a reduced surface roughness and better control of the surface shape than previously possible with this low NA beam. The surface figure of the mirror is well controlled below 0.04 waves in root-mean-square (RMS) at 1.55 mum wavelength, with mirror angle of 45+/-1 degrees. The coupling efficiency is evaluated using a set of polymer waveguides fabricated on the same substrate as the complete proof of concept device. Device insertion loss was measured using a custom built optical test station and a detailed loss analysis was completed to characterize the optical coupling efficiency of the mirror. Surface roughness and angle were also experimentally confirmed. This process opens up a pathway towards large volume fabrication of free-form and high aspect ratio optical components which have not yet pursued, along with well-defined optical structures on a single substrate. In this dissertation, in Chapter 1, we provide an overview of optical surface fabrication in conjunction with current state of the art on fabrication of free form surfaces in macro and microscopic length scale. The need for optical interconnects is introduced and fabrication methods of micro-optical couplers are reviewed in Chapter 2. In Chapter 3, the complete fabrication process of a mirror based coupler is presented including a custom alignment procedure. In Chapter 4, we provide the integration procedure of the optical couplers with waveguides. In Chapter 5, the alignment of two-lithographic methods is discussed. In Chapter 6, we provide the fabrication procedure used for the waveguides. In Chapter 7, the experimental evaluation and testing of the optical coupler is described. We present a custom test station used for angle verification and optical coupler efficiency measurement. In Chapter 8, a detailed loss analysis of the device is presented including suggestions for future reductions in loss. Conclusions and future work considerations are addressed in Chapter 9.

Optimization and limit of a tilt manipulation stage based on the electrowetting-on-dielectric principle

NASA Astrophysics Data System (ADS)

Tan, Xiao; Tao, Zhi; Suzuki, Kenji; Li, Haiwang

2017-12-01

This work designed a new tilt manipulation stage based on the electrowetting-on-dielectric (EWOD) principle as the actuating mechanism and investigated the performance of that stage. The stage was fabricated using a universal MEMS (Micro-Electro-Mechanical System) fabrication method. In the previously demonstrated form of this device, the tilt stage consisted of a top plate that functions as a mirror, a bottom plate that was designed for changing the shape of water droplets, and supporters that were fixed between the top and bottom plate. That device was actuated by a voltage applied to the bottom plate, resulting in a static electric force actuating the shape change in the droplets by moving the top plate in the vertical direction. Previous experimental results indicated that that device can tilt at up to ±1.8°, with a resolution of 7 μm in displacement and 0.05° in angle. By selecting the best combination of the dielectric layer, the tilt angle was maximized. The new device, fabricated using a common and straightforward fabrication method, avoids deflection of the top plate and grounding in the bottom plate. Because of the limit of Teflon and other MEMS materials, this device has a tilt angle in the range of 3.2-3.5° according to the experimental data for friction and the EWOD device limit, which is close to 1.8°. This paper also describe the investigation of the effects of various parameters, e.g., various dielectric materials, thicknesses, and droplet type and volume, on the performance of the stage. The results indicate that the apparent frictions coefficient of the solid-liquid interface may remain constant, i.e., the friction force is proportional to the normal support force and the apparent frictions coefficient.

A new physical method to assess handle properties of fabrics made from wood-based fibers

NASA Astrophysics Data System (ADS)

Abu-Rous, M.; Liftinger, E.; Innerlohinger, J.; Malengier, B.; Vasile, S.

2017-10-01

In this work, the handfeel of fabrics made of wood-based fibers such as viscose, modal and Lyocell was investigated in relation to cotton fabrics applying the Tissue Softness Analyzer (TSA) method in comparison to other classical methods. Two different construction groups of textile were investigated. The validity of TSA in assessing textile softness of these constructions was tested. TSA results were compared to human hand evaluation as well as to classical physical measurements like drape coefficient, ring pull-through and Handle-o-meter, as well as a newer device, the Fabric Touch Tester (FTT). Physical methods as well as human hand assessments mostly agreed on the softest and smoothest range, but showed different rankings in the harder/rougher side fabrics. TSA ranking of softness and smoothness corresponded to the rankings by other physical methods as well as with human hand feel for the basic textile constructions.

Solid-State Neutron Detector Device

NASA Technical Reports Server (NTRS)

Bensaoula, Abdelhak (Inventor); Starikov, David (Inventor); Pillai, Rajeev (Inventor)

2017-01-01

The structure and methods of fabricating a high efficiency compact solid state neutron detector based on III-Nitride semiconductor structures deposited on a substrate. The operation of the device is based on absorption of neutrons, which results in generation of free carriers.

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

PubMed Central

Hagmann, Joseph A.; Le, Son T.; Richter, Curt A.; Seiler, David G.

2016-01-01

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T. PMID:26863449

Fabrication of PDMS-Based Microfluidic Devices: Application for Synthesis of Magnetic Nanoparticles

NASA Astrophysics Data System (ADS)

Thu, Vu Thi; Mai, An Ngoc; Le The Tam; Van Trung, Hoang; Thu, Phung Thi; Tien, Bui Quang; Thuat, Nguyen Tran; Lam, Tran Dai

2016-05-01

In this work, we have developed a convenient approach to synthesize magnetic nanoparticles with relatively high magnetization and controllable sizes. This was realized by combining the traditional co-precipitation method and microfluidic techniques inside microfluidic devices. The device was first designed, and then fabricated using simplified soft-lithography techniques. The device was utilized to synthesize magnetite nanoparticles. The synthesized nanomaterials were thoroughly characterized using field emission scanning electron microscopy and a vibrating sample magnetometer. The results demonstrated that the as-prepared device can be utilized as a simple and effective tool to synthesize magnetic nanoparticles with the sizes less than 10 nm and magnetization more than 50 emu/g. The development of these devices opens new strategies to synthesize nanomaterials with more precise dimensions at narrow size-distribution and with controllable behaviors.

21 CFR 872.3600 - Partially fabricated denture kit.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Partially fabricated denture kit. 872.3600 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3600 Partially fabricated denture kit. (a) Identification. A partially fabricated denture kit is a device composed of connected preformed teeth that is...

21 CFR 872.3600 - Partially fabricated denture kit.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Partially fabricated denture kit. 872.3600 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3600 Partially fabricated denture kit. (a) Identification. A partially fabricated denture kit is a device composed of connected preformed teeth that is...

21 CFR 872.3600 - Partially fabricated denture kit.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Partially fabricated denture kit. 872.3600 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3600 Partially fabricated denture kit. (a) Identification. A partially fabricated denture kit is a device composed of connected preformed teeth that is...

21 CFR 872.3600 - Partially fabricated denture kit.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Partially fabricated denture kit. 872.3600 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3600 Partially fabricated denture kit. (a) Identification. A partially fabricated denture kit is a device composed of connected preformed teeth that is...

Fabrication of polyimide based microfluidic channels for biosensor devices

NASA Astrophysics Data System (ADS)

Zulfiqar, Azeem; Pfreundt, Andrea; Svendsen, Winnie Edith; Dimaki, Maria

2015-03-01

The ever-increasing complexity of the fabrication process of Point-of-care (POC) devices, due to high demand of functional versatility, compact size and ease-of-use, emphasizes the need of multifunctional materials that can be used to simplify this process. Polymers, currently in use for the fabrication of the often needed microfluidic channels, have limitations in terms of their physicochemical properties. Therefore, the use of a multipurpose biocompatible material with better resistance to the chemical, thermal and electrical environment, along with capability of forming closed channel microfluidics is inevitable. This paper demonstrates a novel technique of fabricating microfluidic devices using polyimide (PI) which fulfills the aforementioned properties criteria. A fabrication process to pattern microfluidic channels, using partially cured PI, has been developed by using a dry etching method. The etching parameters are optimized and compared to those used for fully cured PI. Moreover, the formation of closed microfluidic channel on wafer level by bonding two partially cured PI layers or a partially cured PI to glass with high bond strength has been demonstrated. The reproducibility in uniformity of PI is also compared to the most commonly used SU8 polymer, which is a near UV sensitive epoxy resin. The potential applications of PI processing are POC and biosensor devices integrated with microelectronics.

Solution-processed, Self-organized Organic Single Crystal Arrays with Controlled Crystal Orientation

PubMed Central

Kumatani, Akichika; Liu, Chuan; Li, Yun; Darmawan, Peter; Takimiya, Kazuo; Minari, Takeo; Tsukagoshi, Kazuhito

2012-01-01

A facile solution process for the fabrication of organic single crystal semiconductor devices which meets the demand for low-cost and large-area fabrication of high performance electronic devices is demonstrated. In this paper, we develop a bottom-up method which enables direct formation of organic semiconductor single crystals at selected locations with desired orientations. Here oriented growth of one-dimensional organic crystals is achieved by using self-assembly of organic molecules as the driving force to align these crystals in patterned regions. Based upon the self-organized organic single crystals, we fabricate organic field effect transistor arrays which exhibit an average field-effect mobility of 1.1 cm2V−1s−1. This method can be carried out under ambient atmosphere at room temperature, thus particularly promising for production of future plastic electronics. PMID:22563523

Fabrication of Microcapsules for Dye-Doped Polymer-Dispersed Liquid Crystal-Based Smart Windows.

PubMed

Kim, Mingyun; Park, Kyun Joo; Seok, Seunghwan; Ok, Jong Min; Jung, Hee-Tae; Choe, Jaehoon; Kim, Do Hyun

2015-08-19

A dye-doped polymer-dispersed liquid crystal (PDLC) is an attractive material for application in smart windows. Smart windows using a PDLC can be operated simply and have a high contrast ratio compared to those of other devices that employed photochromic or thermochromic material. However, in conventional dye-doped PDLC methods, dye contamination can cause problems and has a limited degree of commercialization of electric smart windows. Here, we report on an approach to resolve dye-related problems by encapsulating the dye in monodispersed capsules. By encapsulation, a fabricated dye-doped PDLC had a contrast ratio of >120 at 600 nm. This fabrication method of encapsulating the dye in a core-shell structured microcapsule in a dye-doped PDLC device provides a practical platform for dye-doped PDLC-based smart windows.

Si nanocrystals-based multilayers for luminescent and photovoltaic device applications

NASA Astrophysics Data System (ADS)

Lu, Peng; Li, Dongke; Cao, Yunqing; Xu, Jun; Chen, Kunji

2018-06-01

Low dimensional Si materials have attracted much attention because they can be developed in many kinds of new-generation nano-electronic and optoelectronic devices, among which Si nanocrystals-based multilayered material is one of the most promising candidates and has been extensively studied. By using multilayered structures, the size and distribution of nanocrystals as well as the barrier thickness between two adjacent Si nanocrystal layers can be well controlled, which is beneficial to the device applications. This paper presents an overview of the fabrication and device applications of Si nanocrystals, especially in luminescent and photovoltaic devices. We first introduce the fabrication methods of Si nanocrystals-based multilayers. Then, we systematically review the utilization of Si nanocrystals in luminescent and photovoltaic devices. Finally, some expectations for further development of the Si nanocrystals-based photonic and photovoltaic devices are proposed. Project supported by the National Natural Science Foundation of China (Nos. 11774155, 11274155).

Review article: Fabrication of nanofluidic devices

PubMed Central

Duan, Chuanhua; Wang, Wei; Xie, Quan

2013-01-01

Thanks to its unique features at the nanoscale, nanofluidics, the study and application of fluid flow in nanochannels/nanopores with at least one characteristic size smaller than 100 nm, has enabled the occurrence of many interesting transport phenomena and has shown great potential in both bio- and energy-related fields. The unprecedented growth of this research field is apparently attributed to the rapid development of micro/nanofabrication techniques. In this review, we summarize recent activities and achievements of nanofabrication for nanofluidic devices, especially those reported in the past four years. Three major nanofabrication strategies, including nanolithography, microelectromechanical system based techniques, and methods using various nanomaterials, are introduced with specific fabrication approaches. Other unconventional fabrication attempts which utilize special polymer properties, various microfabrication failure mechanisms, and macro/microscale machining techniques are also presented. Based on these fabrication techniques, an inclusive guideline for materials and processes selection in the preparation of nanofluidic devices is provided. Finally, technical challenges along with possible opportunities in the present nanofabrication for nanofluidic study are discussed. PMID:23573176

Microplasma fabrication: from semiconductor technology for 2D-chips and microfluidic channels to rapid prototyping and 3D-printing of microplasma devices

NASA Astrophysics Data System (ADS)

Shatford, R.; Karanassios, Vassili

2014-05-01

Microplasmas are receiving attention in recent conferences and current scientific literature. In our laboratory, microplasmas-on-chips proved to be particularly attractive. The 2D- and 3D-chips we developed became hybrid because they were fitted with a quartz plate (quartz was used due to its transparency to UV). Fabrication of 2D- and 3D-chips for microplasma research is described. The fabrication methods described ranged from semiconductor fabrication technology, to Computer Numerical Control (CNC) machining, to 3D-printing. These methods may prove to be useful for those contemplating in entering microplasma research but have no access to expensive semiconductor fabrication equipment.

Delta-Doping at Wafer Level for High Throughput, High Yield Fabrication of Silicon Imaging Arrays

NASA Technical Reports Server (NTRS)

Hoenk, Michael E. (Inventor); Nikzad, Shoulch (Inventor); Jones, Todd J. (Inventor); Greer, Frank (Inventor); Carver, Alexander G. (Inventor)

2014-01-01

Systems and methods for producing high quantum efficiency silicon devices. A silicon MBE has a preparation chamber that provides for cleaning silicon surfaces using an oxygen plasma to remove impurities and a gaseous (dry) NH3 + NF3 room temperature oxide removal process that leaves the silicon surface hydrogen terminated. Silicon wafers up to 8 inches in diameter have devices that can be fabricated using the cleaning procedures and MBE processing, including delta doping.

Peel-and-Stick: Mechanism Study for Efficient Fabrication of Flexible/Transparent Thin-film Electronics

NASA Astrophysics Data System (ADS)

Lee, Chi Hwan; Kim, Jae-Han; Zou, Chenyu; Cho, In Sun; Weisse, Jeffery M.; Nemeth, William; Wang, Qi; van Duin, Adri C. T.; Kim, Taek-Soo; Zheng, Xiaolin

2013-10-01

Peel-and-stick process, or water-assisted transfer printing (WTP), represents an emerging process for transferring fully fabricated thin-film electronic devices with high yield and fidelity from a SiO2/Si wafer to various non-Si based substrates, including papers, plastics and polymers. This study illustrates that the fundamental working principle of the peel-and-stick process is based on the water-assisted subcritical debonding, for which water reduces the critical adhesion energy of metal-SiO2 interface by 70 ~ 80%, leading to clean and high quality transfer of thin-film electronic devices. Water-assisted subcritical debonding is applicable for a range of metal-SiO2 interfaces, enabling the peel-and-stick process as a general and tunable method for fabricating flexible/transparent thin-film electronic devices.

Peel-and-stick: mechanism study for efficient fabrication of flexible/transparent thin-film electronics.

PubMed

Lee, Chi Hwan; Kim, Jae-Han; Zou, Chenyu; Cho, In Sun; Weisse, Jeffery M; Nemeth, William; Wang, Qi; van Duin, Adri C T; Kim, Taek-Soo; Zheng, Xiaolin

2013-10-10

Peel-and-stick process, or water-assisted transfer printing (WTP), represents an emerging process for transferring fully fabricated thin-film electronic devices with high yield and fidelity from a SiO2/Si wafer to various non-Si based substrates, including papers, plastics and polymers. This study illustrates that the fundamental working principle of the peel-and-stick process is based on the water-assisted subcritical debonding, for which water reduces the critical adhesion energy of metal-SiO2 interface by 70 ~ 80%, leading to clean and high quality transfer of thin-film electronic devices. Water-assisted subcritical debonding is applicable for a range of metal-SiO2 interfaces, enabling the peel-and-stick process as a general and tunable method for fabricating flexible/transparent thin-film electronic devices.

Tip-Based Nanofabrication of Arbitrary Shapes of Graphene Nanoribbons for Device Applications

PubMed Central

Estrada, David; Bashir, Rashid; King, William P.

2015-01-01

Graphene nanoribbons (GNRs) have promising applications in future nanoelectronics, chemical sensing and electrical interconnects. Although there are quite a few GNR nanofabrication methods reported, a rapid and low-cost fabrication method that is capable of fabricating arbitrary shapes of GNRs with good-quality is still in demand for using GNRs for device applications. In this paper, we present a tip-based nanofabrication method capable of fabricating arbitrary shapes of GNRs. A heated atomic force microscope (AFM) tip deposits polymer nanowires atop a CVD-grown graphene surface. The polymer nanowires serve as an etch mask to define GNRs through one step of oxygen plasma etching similar to a photoresist in conventional photolithography. Various shapes of GNRs with either linear or curvilinear features are demonstrated. The width of the GNR is around 270 nm and is determined by the width of the depositing polymer nanowire, which we estimate can be scaled down 15 nms. We characterize our TBN-fabricated GNRs using Raman spectroscopy and I-V measurements. The measured sheet resistances of our GNRs fall within the range of 1.65 kΩ/□−1 – 2.64 kΩ/□−1, in agreement with previously reported values. Furthermore, we determined the high-field breakdown current density of GNRs to be approximately 2.94×108 A/cm2. This TBN process is seamlessly compatible with existing nanofabrication processes, and is particularly suitable for fabricating GNR based electronic devices including next generation DNA sequencing technologies and beyond silicon field effect transistors. PMID:26257891

Fabrication of PDMS architecture

NASA Astrophysics Data System (ADS)

Adam, Tijjani; Hashim, U.

2017-03-01

The study report novel, yet simple and flexible fabrication method for micro channel patterning PDMS thin mold on glass surfaces, the method allows microstructures with critical dimensions to be formed using PDMS. Micro channel production is a two-step process. First, soft photolithography methods are implemented to fabricate a reusable mold. The mold is then used to create the micro channel, which consists of SU8, PDMS and glass. The micro channel design was performed using AutoCAD and the fabrication begins by creating a replicable mold. The mold is created on a glass slide. by spin-coating speed between 500 to 1250rpm with an acceleration of 100 rpm/s for 100 and 15 second ramp up and down speed respectively. Channel flow rate based on concentration were measured by analyzing the recorded flow profiles which was collected from the high powered microscope at. 80µ, 70µm, 50µm for inlet channel 1, 2, 3 respectively the channel flow were compared for flow efficiency at different concentrations and Re. Thus, the simplicity of device structure and fabrication makes it feasible to miniaturize it for the development of point-of-care kits, facilitating its use in both clinical and non-clinical environments. With its simple geometric structure and potential for mass commercial fabrication, the device can be developed to become a portable photo detection sensor that can be use for both environmental and diagnostic application.

ZnO nanorods for electronic and photonic device applications

NASA Astrophysics Data System (ADS)

Yi, Gyu-Chul; Yoo, Jinkyoung; Park, Won Il; Jung, Sug Woo; An, Sung Jin; Kim, H. J.; Kim, D. W.

2005-11-01

We report on catalyst-free growth of ZnO nanorods and their nano-scale electrical and optical device applications. Catalyst-free metalorganic vapor-phase epitaxy (MOVPE) enables fabrication of size-controlled high purity ZnO single crystal nanorods. Various high quality nanorod heterostructures and quantum structures based on ZnO nanorods were also prepared using the MOVPE method and characterized using scanning electron microscopy, transmission electron microscopy, and optical spectroscopy. From the photoluminescence spectra of ZnO/Zn 0.8Mg 0.2O nanorod multi-quantum-well structures, in particular, we observed a systematic blue-shift in their PL peak position due to quantum confinement effect of carriers in nanorod quantum structures. For ZnO/ZnMgO coaxial nanorod heterostructures, photoluminescence intensity was significantly increased presumably due to surface passivation and carrier confinement. In addition to the growth and characterizations of ZnO nanorods and their quantum structures, we fabricated nanoscale electronic devices based on ZnO nanorods. We report on fabrication and device characteristics of metal-oxidesemiconductor field effect transistors (MOSFETs), Schottky diodes, and metal-semiconductor field effect transistors (MESFETs) as examples of the nanodevices. In addition, electroluminescent devices were fabricated using vertically aligned ZnO nanorods grown p-type GaN substrates, exhibiting strong visible electroluminescence.

Self-Aligned van der Waals Heterojunction Diodes and Transistors.

PubMed

Sangwan, Vinod K; Beck, Megan E; Henning, Alex; Luo, Jiajia; Bergeron, Hadallia; Kang, Junmo; Balla, Itamar; Inbar, Hadass; Lauhon, Lincoln J; Hersam, Mark C

2018-02-14

A general self-aligned fabrication scheme is reported here for a diverse class of electronic devices based on van der Waals materials and heterojunctions. In particular, self-alignment enables the fabrication of source-gated transistors in monolayer MoS 2 with near-ideal current saturation characteristics and channel lengths down to 135 nm. Furthermore, self-alignment of van der Waals p-n heterojunction diodes achieves complete electrostatic control of both the p-type and n-type constituent semiconductors in a dual-gated geometry, resulting in gate-tunable mean and variance of antiambipolar Gaussian characteristics. Through finite-element device simulations, the operating principles of source-gated transistors and dual-gated antiambipolar devices are elucidated, thus providing design rules for additional devices that employ self-aligned geometries. For example, the versatility of this scheme is demonstrated via contact-doped MoS 2 homojunction diodes and mixed-dimensional heterojunctions based on organic semiconductors. The scalability of this approach is also shown by fabricating self-aligned short-channel transistors with subdiffraction channel lengths in the range of 150-800 nm using photolithography on large-area MoS 2 films grown by chemical vapor deposition. Overall, this self-aligned fabrication method represents an important step toward the scalable integration of van der Waals heterojunction devices into more sophisticated circuits and systems.

Demonstration of nanoimprinted hyperlens array for high-throughput sub-diffraction imaging

NASA Astrophysics Data System (ADS)

Byun, Minsueop; Lee, Dasol; Kim, Minkyung; Kim, Yangdoo; Kim, Kwan; Ok, Jong G.; Rho, Junsuk; Lee, Heon

2017-04-01

Overcoming the resolution limit of conventional optics is regarded as the most important issue in optical imaging science and technology. Although hyperlenses, super-resolution imaging devices based on highly anisotropic dispersion relations that allow the access of high-wavevector components, have recently achieved far-field sub-diffraction imaging in real-time, the previously demonstrated devices have suffered from the extreme difficulties of both the fabrication process and the non-artificial objects placement. This results in restrictions on the practical applications of the hyperlens devices. While implementing large-scale hyperlens arrays in conventional microscopy is desirable to solve such issues, it has not been feasible to fabricate such large-scale hyperlens array with the previously used nanofabrication methods. Here, we suggest a scalable and reliable fabrication process of a large-scale hyperlens device based on direct pattern transfer techniques. We fabricate a 5 cm × 5 cm size hyperlenses array and experimentally demonstrate that it can resolve sub-diffraction features down to 160 nm under 410 nm wavelength visible light. The array-based hyperlens device will provide a simple solution for much more practical far-field and real-time super-resolution imaging which can be widely used in optics, biology, medical science, nanotechnology and other closely related interdisciplinary fields.

Design and Fabrication of High-Efficiency CMOS/CCD Imagers

NASA Technical Reports Server (NTRS)

Pain, Bedabrata

2007-01-01

An architecture for back-illuminated complementary metal oxide/semiconductor (CMOS) and charge-coupled-device (CCD) ultraviolet/visible/near infrared- light image sensors, and a method of fabrication to implement the architecture, are undergoing development. The architecture and method are expected to enable realization of the full potential of back-illuminated CMOS/CCD imagers to perform with high efficiency, high sensitivity, excellent angular response, and in-pixel signal processing. The architecture and method are compatible with next-generation CMOS dielectric-forming and metallization techniques, and the process flow of the method is compatible with process flows typical of the manufacture of very-large-scale integrated (VLSI) circuits. The architecture and method overcome all obstacles that have hitherto prevented high-yield, low-cost fabrication of back-illuminated CMOS/CCD imagers by use of standard VLSI fabrication tools and techniques. It is not possible to discuss the obstacles in detail within the space available for this article. Briefly, the obstacles are posed by the problems of generating light-absorbing layers having desired uniform and accurate thicknesses, passivation of surfaces, forming structures for efficient collection of charge carriers, and wafer-scale thinning (in contradistinction to diescale thinning). A basic element of the present architecture and method - the element that, more than any other, makes it possible to overcome the obstacles - is the use of an alternative starting material: Instead of starting with a conventional bulk-CMOS wafer that consists of a p-doped epitaxial silicon layer grown on a heavily-p-doped silicon substrate, one starts with a special silicon-on-insulator (SOI) wafer that consists of a thermal oxide buried between a lightly p- or n-doped, thick silicon layer and a device silicon layer of appropriate thickness and doping. The thick silicon layer is used as a handle: that is, as a mechanical support for the device silicon layer during micro-fabrication.

Unidirectional Fabric Drape Testing Method

PubMed Central

Mei, Zaihuan; Yang, Jingzhi; Zhou, Ting; Zhou, Hua

2015-01-01

In most cases, fabrics such as curtains, skirts, suit pants and so on are draped under their own gravity parallel to fabric plane while the gravity is perpendicular to fabric plane in traditional drape testing method. As a result, it does not conform to actual situation and the test data is not convincing enough. To overcome this problem, this paper presents a novel method which simulates the real mechanical conditions and ensures the gravity is parallel to the fabric plane. This method applied a low-cost Kinect Sensor device to capture the 3-dimensional (3D) drape profile, thus we obtained the drape degree parameters and aesthetic parameters by 3D reconstruction and image processing and analysis techniques. The experiment was conducted on our self-devised drape-testing instrument by choosing different kinds of weave structure fabrics as our testing samples and the results were compared with those of traditional method and subjective evaluation. Through regression and correlation analysis we found that this novel testing method was significantly correlated with the traditional and subjective evaluation method. We achieved a new, non-contact 3D measurement method for drape testing, namely unidirectional fabric drape testing method. This method is more suitable for evaluating drape behavior because it is more in line with actual mechanical conditions of draped fabrics and has a well consistency with the requirements of visual and aesthetic style of fabrics. PMID:26600387

Recent Advancements in Functionalized Paper-Based Electronics.

PubMed

Lin, Yang; Gritsenko, Dmitry; Liu, Qian; Lu, Xiaonan; Xu, Jie

2016-08-17

Building electronic devices on ubiquitous paper substrates has recently drawn extensive attention due to its light weight, low cost, environmental friendliness, and ease of fabrication. Recently, a myriad of advancements have been made to improve the performance of paper electronics for various applications, such as basic electronic components, energy storage devices, generators, antennas, and electronic circuits. This review aims to summarize this progress and discuss different perspectives of paper electronics as well as the remaining challenges yet to be overcome in this field. Other aspects included in this review are the fundamental characteristics of paper, modification of paper with functional materials, and various methods for device fabrication.

Ultra-Thin Solid-State Nanopores: Fabrication and Applications

NASA Astrophysics Data System (ADS)

Kuan, Aaron Tzeyang

Solid-state nanopores are a nanofluidic platform with unique advantages for single-molecule analysis and filtration applications. However, significant improvements in device performance and scalable fabrication methods are needed to make nanopore devices competitive with existing technologies. This dissertation investigates the potential advantages of ultra-thin nanopores in which the thickness of the membrane is significantly smaller than the nanopore diameter. Novel, scalable fabrication methods were first developed and then utilized to examine device performance for water filtration and single molecule sensing applications. Fabrication of nanometer-thin pores in silicon nitride membranes was achieved using a feedback-controlled ion beam method in which ion sputtering is arrested upon detection of the first few ions that drill through the membrane. Performing fabrication at liquid nitrogen temperatures prevents surface atom rearrangements that have previously complicated similar processes. A novel cross-sectional imaging method was also developed to allow careful examination of the full nanopore geometry. Atomically-thin graphene nanopores were fabricated via an electrical pulse method in which sub-microsecond electrical pulses applied across a graphene membrane in electrolyte solution are used to create a defect in the membrane and controllably enlarge it into a nanopore. This method dramatically increases the accuracy and reliability of graphene nanopore production, allowing consistent production of single nanopores down to subnanometer sizes. In filtration applications in which nanopores are used to selectively restrict the passage of dissolved contaminants, ultra-thin nanopores minimize the flow resistance, increasing throughput and energy-efficiency. The ability of graphene nanopores to separate different ions was characterized via ionic conductance and reversal potential measurements. Graphene nanopores were observed to conduct cations preferentially over anions with selectivity ratios of 100 or higher for pores as large as 20 nm in diameter, suggesting that porous graphene membranes can be used to create highly effective cation exchange membranes for electrodialysis filtration. These surprisingly high selectivities cannot be explained by current models of ionic conduction in graphene nanopores, motivating the development of a new model in which elevated concentrations of mobile cations near the graphene surface generate additional ion selectivity.

High Performance MgO-barrier Magnetic Tunnel Junctions for Flexible and Wearable Spintronic Applications

PubMed Central

Chen, Jun-Yang; Lau, Yong-Chang; Coey, J. M. D.; Li, Mo; Wang, Jian-Ping

2017-01-01

The magnetic tunnel junction (MTJ) using MgO barrier is one of most important building blocks for spintronic devices and has been widely utilized as miniaturized magentic sensors. It could play an important role in wearable medical devices if they can be fabricated on flexible substrates. The required stringent fabrication processes to obtain high quality MgO-barrier MTJs, however, limit its integration with flexible electronics devices. In this work, we have developed a method to fabricate high-performance MgO-barrier MTJs directly onto ultrathin flexible silicon membrane with a thickness of 14 μm and then transfer-and-bond to plastic substrates. Remarkably, such flexible MTJs are fully functional, exhibiting a TMR ratio as high as 190% under bending radii as small as 5 mm. The devices‘ robustness is manifested by its retained excellent performance and unaltered TMR ratio after over 1000 bending cycles. The demonstrated flexible MgO-barrier MTJs opens the door to integrating high-performance spintronic devices in flexible and wearable electronics devices for a plethora of biomedical sensing applications. PMID:28150807

Development and fabrication of an augmented power transistor

NASA Technical Reports Server (NTRS)

Geisler, M. J.; Hill, F. E.; Ostop, J. A.

1983-01-01

The development of device design and processing techniques for the fabrication of an augmented power transistor capable of fast switching and high voltage power conversion is discussed. The major device goals sustaining voltages in the range of 800 to 1000 V at 80 A and 50 A, respectively, at a gain of 14. The transistor switching rise and fall times were both to have been less than 0.5 microseconds. The development of a passivating glass technique to shield the device high voltage junction from moisture and ionic contaminants is discussed as well as the development of an isolated package that separates the thermal and electrical interfaces. A new method was found to alloy the transistors to the molybdenum disc at a relatively low temperature. The measured electrical performance compares well with the predicted optimum design specified in the original proposed design. A 40 mm diameter transistor was fabricated with seven times the emitter area of the earlier 23 mm diameter device.

SU-8 microcantilever with an aperture, fluidic channel, and sensing mechanisms for biological and other applications.

PubMed

Gaitas, Angelo; Hower, Robert W

2014-09-15

We describe a method for fabricating an aperture on a fluidic cantilever device using SU-8 as a structural material. The device can ultimately be used for patch clamping, microinjections, fluidic delivery, fluidic deposition, and micromaterial removal. In the first generation of this device, the initial aperture diameter is 10 μ m and is fabricated on a silicon-on-insulator (SOI) wafer that is structurally used to define the aperture. The aperture can be reduced in size through mask design. This self-aligned process allows for patterning on the sharp tip projecting out of the fluidic plane on the cantilever and is batch fabricated, reducing the cost and time for manufacture. The initial mask, SOI device layer thickness, and the width of the base of the tip define the size of the aperture. The SU-8 micromachined cantilever includes an electrode and a force sensing mechanism. The cantilever can be easily integrated with an atomic force microscope or an optical microscope.

3D printing of tissue-simulating phantoms for calibration of biomedical optical devices

NASA Astrophysics Data System (ADS)

Zhao, Zuhua; Zhou, Ximing; Shen, Shuwei; Liu, Guangli; Yuan, Li; Meng, Yuquan; Lv, Xiang; Shao, Pengfei; Dong, Erbao; Xu, Ronald X.

2016-10-01

Clinical utility of many biomedical optical devices is limited by the lack of effective and traceable calibration methods. Optical phantoms that simulate biological tissues used for optical device calibration have been explored. However, these phantoms can hardly simulate both structural and optical properties of multi-layered biological tissue. To address this limitation, we develop a 3D printing production line that integrates spin coating, light-cured 3D printing and Fused Deposition Modeling (FDM) for freeform fabrication of optical phantoms with mechanical and optical heterogeneities. With the gel wax Polydimethylsiloxane (PDMS), and colorless light-curable ink as matrix materials, titanium dioxide (TiO2) powder as the scattering ingredient, graphite powder and black carbon as the absorption ingredient, a multilayer phantom with high-precision is fabricated. The absorption and scattering coefficients of each layer are measured by a double integrating sphere system. The results demonstrate that the system has the potential to fabricate reliable tissue-simulating phantoms to calibrate optical imaging devices.

The development of differential inductors using double air-bridge structure based on integrated passive device technology

NASA Astrophysics Data System (ADS)

Li, Yang; Yao, Zhao; Fu, Xiao-Qian; Li, Zhi-Ming; Shan, Fu-Kai; Wang, Cong

2017-05-01

Recently, integrated passive devices have become increasingly popular; inductor realization, in particular, offers interesting high performance for RF modules and systems. In this paper, a development of differential inductor fabricated by integrated passive devices technology using a double air-bridge structure is presented. A study of the model development of the differential inductor is first demonstrated. In this model section, a segment box analysis method is applied to provide a clear presentation of the differential inductor. Compared with other work that only shows a brief description of the process, the integrated passive devices process used to fabricate the inductor in this study is elaborated on. Finally, a characterization of differential inductors with different physical layout parameters is illustrated based on inductance and quality factors, which provides a valuable reference for realizing high performance. The proposed work provides a good solution for the design, fabrication and practical application of RF modules and systems.

Bottom-up fabrication of paper-based microchips by blade coating of cellulose microfibers on a patterned surface.

PubMed

Gao, Bingbing; Liu, Hong; Gu, Zhongze

2014-12-23

We report a method for the bottom-up fabrication of paper-based capillary microchips by the blade coating of cellulose microfibers on a patterned surface. The fabrication process is similar to the paper-making process in which an aqueous suspension of cellulose microfibers is used as the starting material and is blade-coated onto a polypropylene substrate patterned using an inkjet printer. After water evaporation, the cellulose microfibers form a porous, hydrophilic, paperlike pattern that wicks aqueous solution by capillary action. This method enables simple, fast, inexpensive fabrication of paper-based capillary channels with both width and height down to about 10 μm. When this method is used, the capillary microfluidic chip for the colorimetric detection of glucose and total protein is fabricated, and the assay requires only 0.30 μL of sample, which is 240 times smaller than for paper devices fabricated using photolithography.

An isopropanol-assisted fabrication strategy of pinhole-free perovskite films in air for efficient and stable planar perovskite solar cells

NASA Astrophysics Data System (ADS)

Ren, Ziqiu; Zhu, Menghua; Li, Xin; Dong, Cunku

2017-09-01

As a promising photovoltaic device, perovskite solar cells have attracted numerous attention in recent years, where forming a compact and pinhole-free perovskite film in air is of great importance. Herein, we evaluate highly efficient and air stable planar perovskite solar cells in air (relative humidity over 50%) with the modified two-step sequential deposition method by adjusting the CH3NH3I (MAI) concentrations and regulating the crystallization process of the perovskite film. The optimum MAI concentration is 60 mg mL-1 in isopropanol. With a planar structure of FTO/TiO2/MAPbI3/spiro-OMeTAD/Au, the efficient devices composed of compact and pinhole-free perovskite films are constructed in air, achieving a high efficiency of up to 15.10% and maintaining over 80% after 20 days storing without any encapsulation in air. With a facile fabrication process and high photovoltaic performance, this work represents a promising method for fabricating low-cost, highly efficient and stable photovoltaic device.

On-chip self-assembly of cell embedded microstructures to vascular-like microtubes.

PubMed

Yue, Tao; Nakajima, Masahiro; Takeuchi, Masaru; Hu, Chengzhi; Huang, Qiang; Fukuda, Toshio

2014-03-21

Currently, research on the construction of vascular-like tubular structures is a hot area of tissue engineering, since it has potential applications in the building of artificial blood vessels. In this paper, we report a fluidic self-assembly method using cell embedded microstructures to construct vascular-like microtubes. A novel 4-layer microfluidic device was fabricated using polydimethylsiloxane (PDMS), which contains fabrication, self-assembly and extraction areas inside one channel. Cell embedded microstructures were directly fabricated using poly(ethylene glycol) diacrylate (PEGDA) in the fabrication area, namely on-chip fabrication. Self-assembly of the fabricated microstructures was performed in the assembly area which has a micro well. Assembled tubular structures (microtubes) were extracted outside the channel into culture dishes using a normally closed (NC) micro valve in the extraction area. The self-assembly mechanism was experimentally demonstrated. The performance of the NC micro valve and embedded cell concentration were both evaluated. Fibroblast (NIH/3T3) embedded vascular-like microtubes were constructed inside this reusable microfluidic device.

Stretchable and high-performance supercapacitors with crumpled graphene papers.

PubMed

Zang, Jianfeng; Cao, Changyong; Feng, Yaying; Liu, Jie; Zhao, Xuanhe

2014-10-01

Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretchable and high-performance electrodes for supercapacitors based on new crumpled-graphene papers. Electrolyte-mediated-graphene paper bonded on a compliant substrate can be crumpled into self-organized patterns by harnessing mechanical instabilities in the graphene paper. As the substrate is stretched, the crumpled patterns unfold, maintaining high reliability of the graphene paper under multiple cycles of large deformation. Supercapacitor electrodes based on the crumpled graphene papers exhibit a unique combination of high stretchability (e.g., linear strain ~300%, areal strain ~800%), high electrochemical performance (e.g., specific capacitance ~196 F g(-1)), and high reliability (e.g., over 1000 stretch/relax cycles). An all-solid-state supercapacitor capable of large deformation is further fabricated to demonstrate practical applications of the crumpled-graphene-paper electrodes. Our method and design open a wide range of opportunities for manufacturing future energy-storage devices with desired deformability together with high performance.

Stretchable and High-Performance Supercapacitors with Crumpled Graphene Papers

NASA Astrophysics Data System (ADS)

Zang, Jianfeng; Cao, Changyong; Feng, Yaying; Liu, Jie; Zhao, Xuanhe

2014-10-01

Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretchable and high-performance electrodes for supercapacitors based on new crumpled-graphene papers. Electrolyte-mediated-graphene paper bonded on a compliant substrate can be crumpled into self-organized patterns by harnessing mechanical instabilities in the graphene paper. As the substrate is stretched, the crumpled patterns unfold, maintaining high reliability of the graphene paper under multiple cycles of large deformation. Supercapacitor electrodes based on the crumpled graphene papers exhibit a unique combination of high stretchability (e.g., linear strain ~300%, areal strain ~800%), high electrochemical performance (e.g., specific capacitance ~196 F g-1), and high reliability (e.g., over 1000 stretch/relax cycles). An all-solid-state supercapacitor capable of large deformation is further fabricated to demonstrate practical applications of the crumpled-graphene-paper electrodes. Our method and design open a wide range of opportunities for manufacturing future energy-storage devices with desired deformability together with high performance.

Stretchable and High-Performance Supercapacitors with Crumpled Graphene Papers

PubMed Central

Zang, Jianfeng; Cao, Changyong; Feng, Yaying; Liu, Jie; Zhao, Xuanhe

2014-01-01

Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretchable and high-performance electrodes for supercapacitors based on new crumpled-graphene papers. Electrolyte-mediated-graphene paper bonded on a compliant substrate can be crumpled into self-organized patterns by harnessing mechanical instabilities in the graphene paper. As the substrate is stretched, the crumpled patterns unfold, maintaining high reliability of the graphene paper under multiple cycles of large deformation. Supercapacitor electrodes based on the crumpled graphene papers exhibit a unique combination of high stretchability (e.g., linear strain ~300%, areal strain ~800%), high electrochemical performance (e.g., specific capacitance ~196 F g−1), and high reliability (e.g., over 1000 stretch/relax cycles). An all-solid-state supercapacitor capable of large deformation is further fabricated to demonstrate practical applications of the crumpled-graphene-paper electrodes. Our method and design open a wide range of opportunities for manufacturing future energy-storage devices with desired deformability together with high performance. PMID:25270673

Facile fabrication of a poly(ethylene terephthalate) membrane filter with precise arrangement of through-holes

NASA Astrophysics Data System (ADS)

Kihara, Naoto; Odaka, Hidefumi; Kuboyama, Daiki; Onoshima, Daisuke; Ishikawa, Kenji; Baba, Yoshinobu; Hori, Masaru

2018-03-01

Although membrane filters are indispensable in biochemical analysis fields, most methods for through-hole fabrication are complex and inefficient. We developed a simple method of fabricating poly(ethylene terephthalate) (PET) membrane filters with a precise arrangement of through-holes for the isolation of circulating tumor cells (CTCs) based on their size. By photolithography and dry etching, highly packed 380,000 through-holes with a diameter of 7 µm were able to cover a whole area with a diameter of 13 mm. Device fabrication for the size-based capture of rare cells in blood such as CTCs is realized in this study.

Study of thickness and uniformity of oxide passivation with DI-O3 on silicon substrate for electronic and photonic applications

NASA Astrophysics Data System (ADS)

Sharma, Mamta; Hazra, Purnima; Singh, Satyendra Kumar

2018-05-01

Since the beginning of semiconductor fabrication technology evolution, clean and passivated substrate surface is one of the prime requirements for fabrication of Electronic and optoelectronic device fabrication. However, as the scale of silicon circuits and device architectures are continuously decreased from micrometer to nanometer (from VLSI to ULSI technology), the cleaning methods to achieve better wafer surface qualities has raised research interests. The development of controlled and uniform silicon dioxide is the most effective and reliable way to achieve better wafer surface quality for fabrication of electronic devices. On the other hand, in order to meet the requirement of high environment safety/regulatory standards, the innovation of cleaning technology is also in demand. The controlled silicon dioxide layer formed by oxidant de-ionized ozonated water has better uniformity. As the uniformity of the controlled silicon dioxide layer is improved on the substrate, it enhances the performance of the devices. We can increase the thickness of oxide layer, by increasing the ozone time treatment. We reported first time to measurement of thickness of controlled silicon dioxide layer and obtained the uniform layer for same ozone time.

Fabrication and Characterization of Thermo-Optic Mach-Zehnder Silicon Modulator

NASA Astrophysics Data System (ADS)

Park, Yeongho

This thesis focuses on the modeling, design, and fabrication of the Thermo-Optic Mach-Zehnder Modulator, which is one of the simple active devices in silicon photonics. The Mach-Zehnder interferometer (MZI) was formed as an optical path on a silicon on insulator (SOI) wafer of 2040+/-80 nm thick, and the thermo-optic effect was used to modulate the infrared light of 1553 nm wavelength by controlling the temperature of the one arm of the MZI. To fabricate and understand the Si photonic device, the whole process from theory to the measurement setup is introduced. Additionally, all the fabrication details and some informative experiments which were performed during the fabrication are discussed for students who will study the more developed devices. The width of the designed waveguide is 4 mum, but the width of the fabricated waveguide is 3.0+/-0.2 mum due to the isotropic etching. For the lithography for both patterning waveguides and metal contacts, the AZ 5214 photoresist was used, and the details of the lithography was discussed. Furthermore, the lift-off method was performed and introduced to solve the over-etching problem. The fabricated metal contacts can withstand up to 1.6W, and the electric power 0.3W is required to make Pi phase difference according to the simulation result by the simulation software Lumerical. The optical output of the device was not detected due to the huge losses from the sidewall roughness and the insertion loss, so it is discussed in the experimental measurement chapter.

Fabrication of p(+)-n junction GaAs solar cells by a novel method

NASA Technical Reports Server (NTRS)

Ghandhi, S. K.; Mathur, G.; Rode, H.; Borrego, J. M.

1984-01-01

A novel method for making p(+)-n diffused junction GaAs solar cells, with the formation of a diffusion source, an anti-reflective coating, and a protective cover glass in a single chemical-vapor deposition operation is discussed. Consideration is given to device fabrication and to solar-cell characteristics. The advantages of the technique are that the number of process steps is kept to an absolute minimum, the fabrication procedure is low-cost, and the GaAs surface is protected during the entire operation.

Current progress and technical challenges of flexible liquid crystal displays

NASA Astrophysics Data System (ADS)

Fujikake, Hideo; Sato, Hiroto

2009-02-01

We focused on several technical approaches to flexible liquid crystal (LC) display in this report. We have been developing flexible displays using plastic film substrates based on polymer-dispersed LC technology with molecular alignment control. In our representative devices, molecular-aligned polymer walls keep plastic-substrate gap constant without LC alignment disorder, and aligned polymer networks create monostable switching of fast-response ferroelectric LC (FLC) for grayscale capability. In the fabrication process, a high-viscosity FLC/monomer solution was printed, sandwiched and pressed between plastic substrates. Then the polymer walls and networks were sequentially formed based on photo-polymerization-induced phase separation in the nematic phase by two exposure processes of patterned and uniform ultraviolet light. The two flexible backlight films of direct illumination and light-guide methods using small three-primary-color light-emitting diodes were fabricated to obtain high-visibility display images. The fabricated flexible FLC panels were driven by external transistor arrays, internal organic thin film transistor (TFT) arrays, and poly-Si TFT arrays. We achieved full-color moving-image displays using the flexible FLC panel and the flexible backlight film based on field-sequential-color driving technique. Otherwise, for backlight-free flexible LC displays, flexible reflective devices of twisted guest-host nematic LC and cholesteric LC were discussed with molecular-aligned polymer walls. Singlesubstrate device structure and fabrication method using self-standing polymer-stabilized nematic LC film and polymer ceiling layer were also proposed for obtaining LC devices with excellent flexibility.

Electrical and optical characteristics of heterojunction devices composed of silicon nanowires and mercury selenide nanoparticle films on flexible plastics.

PubMed

Yeo, Minje; Yun, Junggwon; Kim, Sangsig

2013-09-01

A pn heterojunction device based on p-type silicon (Si) nanowires (NWs) prepared by top-down method and n-type mercury selenide (HgSe) nanoparticles (NPs) synthesized by the colloidal method have been fabricated on a flexible plastic substrate. The synthesized HgSe NPs were analyzed through the effective mass approximation. The characteristics of the heterojunction device were examined and studied with the energy band diagram. The device showed typical diode characteristics with a turn-on voltage of 1.5 V and exhibited a high rectification ratio of 10(3) under relatively low forward bias. Under illumination of 633-nm-wavelength light, the device presented photocurrent efficiency of 117.5 and 20.1 nA/W under forward bias and reverse bias conditions, respectively. Moreover, the photocurrent characteristics of the device have been determined by bending of the plastic substrate upward and downward with strain of 0.8%. Even though the photocurrent efficiency has fluctuations during the bending cycles, the values are roughly maintained for 10(4) bending cycles. This result indicates that the fabricated heterojunction device has the potential to be applied as fundamental elements of flexible nanoelectronics.

Electra-optical device including a nitrogen containing electrolyte

DOEpatents

Bates, J.B.; Dudney, N.J.; Gruzalski, G.R.; Luck, C.F.

1995-10-03

Described is a thin-film battery, especially a thin-film microbattery, and a method for making same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode. Configured as a microbattery, the battery can be fabricated directly onto a semiconductor chip, onto the semiconductor die or onto any portion of the chip carrier. The battery can be fabricated to any specified size or shape to meet the requirements of a particular application. The battery is fabricated of solid state materials and is capable of operation between {minus}15 C and 150 C.

0.8 V nanogenerator for mechanical energy harvesting using bismuth titanate-PDMS nanocomposite

NASA Astrophysics Data System (ADS)

Abinnas, N.; Baskaran, P.; Harish, S.; Ganesh, R. Sankar; Navaneethan, M.; Nisha, K. D.; Ponnusamy, S.; Muthamizhchelvan, C.; Ikeda, H.; Hayakawa, Y.

2017-10-01

We present a novel, low-cost approach to fabricate piezoelectric nanogenerators using Bismuth titanate (BiT)/Polydimethylsiloxane (PDMS) nanocomposite. The nanogenerator has the advantage of the simple process of fabrication and is eco-friendly. This simple device was fabricated to harvest the energy released from finger tapping. This device generated an output of 0.8 V. The BiT samples were synthesized by wet chemical method. The structural, dielectric and ferroelectric properties of the samples were analyzed. Phase analysis using X-ray diffraction indicated that the phase structure was orthorhombic. The FESEM images of the sample calcined at 700 °C exhibited sheet-like morphology. Further characterizations like XPS, Raman studies, TEM were done.

Method of fabricating a microelectronic device package with an integral window

DOEpatents

Peterson, Kenneth A.; Watson, Robert D.

2003-01-01

A method of fabricating a microelectronic device package with an integral window for providing optical access through an aperture in the package. The package is made of a multilayered insulating material, e.g., a low-temperature cofired ceramic (LTCC) or high-temperature cofired ceramic (HTCC). The window is inserted in-between personalized layers of ceramic green tape during stackup and registration. Then, during baking and firing, the integral window is simultaneously bonded to the sintered ceramic layers of the densified package. Next, the microelectronic device is flip-chip bonded to cofired thick-film metallized traces on the package, where the light-sensitive side is optically accessible through the window. Finally, a cover lid is attached to the opposite side of the package. The result is a compact, low-profile package, flip-chip bonded, hermetically-sealed package having an integral window.

Geometrical effect characterization of femtosecond-laser manufactured glass microfluidic chips based on optical manipulation of submicroparticles

NASA Astrophysics Data System (ADS)

Kotsifaki, Domna G.; Mackenzie, Mark D.; Polydefki, Georgia; Kar, Ajoy K.; Makropoulou, Mersini; Serafetinides, Alexandros A.

2017-12-01

Microfluidic devices provide a platform with wide ranging applications from environmental monitoring to disease diagnosis. They offer substantive advantages but are often not optimized or designed to be used by nonexpert researchers. Microchannels of a microanalysis platform and their geometrical characterization are of eminent importance when designing such devices. We present a method that is used to optimize each microchannel within a device using high-throughput particle manipulation. For this purpose, glass-based microfluidic devices, with three-dimensional channel networks of several geometrical sizes, were fabricated by employing laser fabrication techniques. The effect of channel geometry was investigated by employing an optical tweezer. The optical trapping force depends on the flow velocity that is associated with the dimensions of the microchannel. We observe a linear dependence of the trapping efficiency and of the fluid flow velocity, with the channel dimensions. We determined that the highest trapping efficiency was achieved for microchannels with aspect ratio equal to one. Numerical simulation validated the impact of the device design dimensions on the trapping efficiency. This investigation indicates that the geometrical characteristics, the flow velocity, and trapping efficiency are crucial and should be considered when fabricating microfluidic devices for cell studies.

Theoretical limits of the multistacked 1D and 2D microstructured inorganic solar cells

NASA Astrophysics Data System (ADS)

Yengel, Emre; Karaagac, Hakan; VJ, Logeeswaran; Islam, M. Saif

2015-09-01

Recent studies in monocrystalline semiconductor solar cells are focused on mechanically stacking multiple cells from different materials to increase the power conversion efficiency. Although, the results show promising increase in the device performance, the cost remains as the main drawback. In this study, we calculated the theoretical limits of multistacked 1D and 2D microstructered inorganic monocrstalline solar cells. This system is studied for Si and Ge material pair. The results show promising improvements in the surface reflection due to enhanced light trapping caused by photon-microstructures interactions. The theoretical results are also supported with surface reflection and angular dependent power conversion efficiency measurements of 2D axial microwall solar cells. We address the challenge of cost reduction by proposing to use our recently reported mass-manufacturable fracture-transfer- printing method which enables the use of a monocrystalline substrate wafer for repeated fabrication of devices by consuming only few microns of materials in each layer of devices. We calculated thickness dependent power conversion efficiencies of multistacked Si/Ge microstructured solar cells and found the power conversion efficiency to saturate at 26% with a combined device thickness of 30 μm. Besides having benefits of fabricating low-cost, light weight, flexible, semi-transparent, and highly efficient devices, the proposed fabrication method is applicable for other III-V materials and compounds to further increase the power conversion efficiency above 35% range.

Radio Frequency Magnetron Sputtering Deposition of TiO2 Thin Films and Their Perovskite Solar Cell Applications

PubMed Central

Chen, Cong; Cheng, Yu; Dai, Qilin; Song, Hongwei

2015-01-01

In this work, we report a physical deposition based, compact (cp) layer synthesis for planar heterojunction perovskite solar cells. Typical solution-based synthesis of cp layer for perovskite solar cells involves low-quality of thin films, high-temperature annealing, non-flexible devices, limitation of large-scale production and that the effects of the cp layer on carrier transport have not been fully understood. In this research, using radio frequency magnetron sputtering (RFMS), TiO2 cp layers were fabricated and the thickness could be controlled by deposition time; CH3NH3PbI3 films were prepared by evaporation & immersion (E & I) method, in which PbI2 films made by thermal evaporation technique were immersed in CH3NH3I solution. The devices exhibit power conversion efficiency (PCE) of 12.1% and the photovoltaic performance can maintain 77% of its initial PCE after 1440 h. The method developed in this study has the capability of fabricating large active area devices (40 × 40 mm2) showing a promising PCE of 4.8%. Low temperature and flexible devices were realized and a PCE of 8.9% was obtained on the PET/ITO substrates. These approaches could be used in thin film based solar cells which require high-quality films leading to reduced fabrication cost and improved device performance. PMID:26631493

Thermoelectric devices and applications for the same

DOEpatents

DeSteese, John G [Kennewick, WA; Olsen, Larry C [Richland, WA; Martin, Peter M [Kennewick, WA

2010-12-14

High performance thin film thermoelectric couples and methods of making the same are disclosed. Such couples allow fabrication of at least microwatt to watt-level power supply devices operating at voltages greater than one volt even when activated by only small temperature differences.

Thermoelectric devices and applications for the same

DOEpatents

Olsen, Larry C.; DeSteese, John G.; Martin, Peter M.; Johnston, John W.; Peters, Timothy J.

2016-03-08

High performance thin film thermoelectric couples and methods of making the same are disclosed. Such couples allow fabrication of at least microwatt to watt-level power supply devices operating at voltages greater than one volt even when activated by only small temperature differences.

Open-source, community-driven microfluidics with Metafluidics.

PubMed

Kong, David S; Thorsen, Todd A; Babb, Jonathan; Wick, Scott T; Gam, Jeremy J; Weiss, Ron; Carr, Peter A

2017-06-07

Microfluidic devices have the potential to automate and miniaturize biological experiments, but open-source sharing of device designs has lagged behind sharing of other resources such as software. Synthetic biologists have used microfluidics for DNA assembly, cell-free expression, and cell culture, but a combination of expense, device complexity, and reliance on custom set-ups hampers their widespread adoption. We present Metafluidics, an open-source, community-driven repository that hosts digital design files, assembly specifications, and open-source software to enable users to build, configure, and operate a microfluidic device. We use Metafluidics to share designs and fabrication instructions for both a microfluidic ring-mixer device and a 32-channel tabletop microfluidic controller. This device and controller are applied to build genetic circuits using standard DNA assembly methods including ligation, Gateway, Gibson, and Golden Gate. Metafluidics is intended to enable a broad community of engineers, DIY enthusiasts, and other nontraditional participants with limited fabrication skills to contribute to microfluidic research.

Design, fabrication and analysis of integrated optical waveguide devices

NASA Astrophysics Data System (ADS)

Sikorski, Yuri

Throughout the present dissertation, the main effort has been to develop the set of design rules for optical integrated circuits (OIC). At the present time, when planar optical integrated circuits seem to be the leading technology, and industry is heading towards much higher levels of integration, such design rules become necessary. It is known that analysis of light propagation in rectangular waveguides can not be carried out exactly. Various approximations become necessary, and their validity is discussed in this text. Various methods are used in the text for calculating the same problems, and results are compared. A few new concepts have been suggested to avoid approximations used elsewhere. The second part of this dissertation is directed to the development of a new technique for the fabrication of optical integrated circuits inside optical glass. This technique is based on the use of ultrafast laser pulses to alter the properties of glasses. Using this method we demonstrated the possibility of changing the refractive index of various passive and active optical glasses as well as ablating the material on the surface in a controlled fashion. A number of optical waveguide devices (e.g. waveguides, directional couplers, diffraction gratings, fiber Bragg gratings, V-grooves in dual-clad optical fibers, optical waveguide amplifiers) were fabricated and tested. Testing included measurements of loss/throughput, near-field mode profiles, efficiency and thermal stability. All of the experimental setup and test results are reported in the dissertation. We also demonstrated the possibility of using this technique to fabricate future bio-optical devices that will incorporate an OIC and a microfluidic circuit on a single substrate. Our results are expected to serve as a guide for the design and fabrication of a new generation of integrated optical and bio-optical devices.

Fabrication system, method and apparatus for microelectromechanical devices

NASA Technical Reports Server (NTRS)

Johnson, A. David (Inventor); Busta, Heinz H. (Inventor); Nowicki, Ronald S. (Inventor)

1999-01-01

A fabrication system and method of fabrication for producing microelectromechanical devices such as field-effect displays using thin-film technology. A spacer is carried at its proximal end on the surface of a substrate having field-effect emitters with the spacer being enabled for tilting movement from a nested position to a deployed position which is orthogonal to the plane of the substrate. An actuator is formed with one end connected with the substrate and another end connected with spacer. The actuator is made of a shape memory alloy material which contracts when heated through the material's phase-change transition temperature. Contraction of the actuator exerts a pulling force on the spacer which is tilted to the deployed position. A plurality of the spacers are distributed over the area of the display. A glass plate having a phosphor-coated surface is fitted over the distal ends of the deployed spacer.

Flexible ITO-free organic solar cells applying aqueous solution-processed V2O5 hole transport layer: An outdoor stability study

NASA Astrophysics Data System (ADS)

Lima, F. Anderson S.; Beliatis, Michail J.; Roth, Bérenger; Andersen, Thomas R.; Bortoti, Andressa; Reyna, Yegraf; Castro, Eryza; Vasconcelos, Igor F.; Gevorgyan, Suren A.; Krebs, Frederik C.; Lira-Cantu, Mónica

2016-02-01

Solution processable semiconductor oxides have opened a new paradigm for the enhancement of the lifetime of thin film solar cells. Their fabrication by low-cost and environmentally friendly solution-processable methods makes them ideal barrier (hole and electron) transport layers. In this work, we fabricate flexible ITO-free organic solar cells (OPV) by printing methods applying an aqueous solution-processed V2O5 as the hole transport layer (HTL) and compared them to devices applying PEDOT:PSS. The transparent conducting electrode was PET/Ag/PEDOT/ZnO, and the OPV configuration was PET/Ag/PEDOT/ZnO/P3HT:PC60BM/HTL/Ag. Outdoor stability analyses carried out for more than 900 h revealed higher stability for devices fabricated with the aqueous solution-processed V2O5.

Limiting factors in the production of deep microstructures

NASA Astrophysics Data System (ADS)

Tolfree, David W. L.; O'Neill, William; Tunna, Leslie; Sutcliffe, Christopher

1999-10-01

Microsystems increasingly require precision deep microstructures that can be cost-effectively designed and manufactured. New products must be able to meet the demands of the rapidly growing markets for microfluidic, micro- optical and micromechanical devices in industrial sectors which include chemicals, pharmaceuticals, biosciences, medicine and food. The realization of such products, first requires an effective process to design and manufacture prototypes. Two process methods used for the fabrication of high aspect-ratio microstructures are based on X-ray beam lithography with electroforming processes and direct micromachining with a frequency multiplied Nd:YAG laser using nanosecond pulse widths. Factors which limit the efficiency and precision obtainable using such processes are important parameters when deciding on the best fabrication method to use. A basic microstructure with narrow channels suitable for a microfluidic mixer have been fabricated using both these techniques and comparisons made of the limitations and suitability of the processes in respect of fast prototyping and manufacture or working devices.

A Simple, Low-Cost Platform for Real-Time Isothermal Nucleic Acid Amplification

PubMed Central

Craw, Pascal; Mackay, Ruth E.; Naveenathayalan, Angel; Hudson, Chris; Branavan, Manoharanehru; Sadiq, S. Tariq; Balachandran, Wamadeva

2015-01-01

Advances in microfluidics and the introduction of isothermal nucleic acid amplification assays have resulted in a range of solutions for nucleic acid amplification tests suited for point of care and field use. However, miniaturisation of instrumentation for such assays has not seen such rapid advances and fluorescence based assays still depend on complex, bulky and expensive optics such as fluorescence microscopes, photomultiplier tubes and sensitive lens assemblies. In this work we demonstrate a robust, low cost platform for isothermal nucleic acid amplification on a microfluidic device. Using easily obtainable materials and commercial off-the-shelf components, we show real time fluorescence detection using a low cost photodiode and operational amplifier without need for lenses. Temperature regulation on the device is achieved using a heater fabricated with standard printed circuit board fabrication methods. These facile construction methods allow fabrications at a cost compatible with widespread deployment to resource poor settings. PMID:26389913

Environmentally-assisted technique for transferring devices onto non-conventional substrates

DOEpatents

Lee, Chi-Hwan; Kim, Dong Rip; Zheng, Xiaolin

2016-05-10

A device fabrication method includes: (1) providing a growth substrate including an oxide layer; (2) forming a metal layer over the oxide layer; (3) forming a stack of device layers over the metal layer; (4) performing fluid-assisted interfacial debonding of the metal layer to separate the stack of device layers and the metal layer from the growth substrate; and (5) affixing the stack of device layers to a target substrate.

Two Photon Polymerization of Microneedles for Transdermal Drug Delivery

PubMed Central

Gittard, Shaun D.; Ovsianikov, Aleksandr; Chichkov, Boris N.; Doraiswamy, Anand; Narayan, Roger J.

2010-01-01

Importance of the field Microneedles are small-scale devices that are finding use for transdermal delivery of protein-based pharmacologic agents and nucleic acid-based pharmacologic agents; however, microneedles prepared using conventional microelectronics-based technologies have several shortcomings, which have limited translation of these devices into widespread clinical use. Areas covered in this review Two photon polymerization is a laser-based rapid prototyping technique that has been recently used for direct fabrication of hollow microneedles with a wide variety of geometries. In addition, an indirect rapid prototyping method that involves two photon polymerization and polydimethyl siloxane micromolding has been used for fabrication of solid microneedles with exceptional mechanical properties. What the reader will gain In this review, the use of two photon polymerization for fabricating in-plane and out-of-plane hollow microneedle arrays is described. The use of two photon polymerization-micromolding for fabrication of solid microneedles is also reviewed. In addition, fabrication of microneedles with antimicrobial properties is discussed; antimicrobial microneedles may reduce the risk of infection associated with formation of channels through the stratum corneum. Take home message It is anticipated that the use of two photon polymerization as well as two photon polymerization-micromolding for fabrication of microneedles and other microstructured drug delivery devices will increase over the coming years. PMID:20205601

Lambertian white top-emitting organic light emitting device with carbon nanotube cathode

NASA Astrophysics Data System (ADS)

Freitag, P.; Zakhidov, Al. A.; Luessem, B.; Zakhidov, A. A.; Leo, K.

2012-12-01

We demonstrate that white organic light emitting devices (OLEDs) with top carbon nanotube (CNT) electrodes show almost no microcavity effect and exhibit essentially Lambertian emission. CNT top electrodes were applied by direct lamination of multiwall CNT sheets onto white small molecule OLED stack. The devices show an external quantum efficiency of 1.5% and high color rendering index of 70. Due to elimination of the cavity effect, the devices show good color stability for different viewing angles. Thus, CNT electrodes are a viable alternative to thin semitransparent metallic films, where the strong cavity effect causes spectral shift and non-Lambertian angular dependence. Our method of the device fabrication is simple yet effective and compatible with virtually any small molecule organic semiconductor stack. It is also compatible with flexible substrates and roll-to-roll fabrication.

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.

Fabrication of robust tooling for mass production of polymeric microfluidic devices

NASA Astrophysics Data System (ADS)

Fu, G.; Tor, S. B.; Loh, N. H.; Hardt, D. E.

2010-08-01

Polymer microfluidic devices are gaining popularity for bio-applications. In both commonly used methods for the fabrication of polymer microfluidic devices, i.e. injection molding and hot-embossing, the quality of a mold insert is of high importance. Micro powder injection molding (μPIM) provides a suitable option for metal mold insert fabrication. In this paper, two mold inserts with micro-features of different patterns and sizes were produced using 316L stainless steel powder and an in-house binder system. The mold inserts were successfully used to produce cyclic olefin copolymer (COC, trade name TOPAS) micromixer plates with micro-channels of widths 100 µm and 50 µm. Compared with CNC-machined hot work steel mold inserts, the quality of the micro-channels is better as far as geometrical quality and dimensional tolerance are concerned. However, surface finish and flatness of the μPIM mold inserts are inferior to those of CNC-machined mold inserts.

Facile Method and Novel Dielectric Material Using a Nanoparticle-Doped Thermoplastic Elastomer Composite Fabric for Triboelectric Nanogenerator Applications.

PubMed

Zhang, Zhi; Chen, Ying; Debeli, Dereje Kebebew; Guo, Jian Sheng

2018-04-18

The trends toward flexible and wearable electronic devices give rise to the attention of triboelectric nanogenerators (TENGs) which can gather tiny energy from human body motions. However, to accommodate the needs, wearable electronics are still facing challenges for choosing a better dielectric material to improve their performance and practicability. As a kind of synthetic rubber, the thermoplastic elastomer (TPE) contains many advantages such as lightweight, good flexibility, high tear strength, and friction resistance, accompanied by good adhesion with fabrics, which is an optimal candidate of dielectric materials. Herein, a novel nanoparticle (NP)-doped TPE composite fabric-based TENG (TF-TENG) has been developed, which operates based on the NP-doped TPE composite fabric using a facile coating method. The performances of the TENG device are systematically investigated under various thicknesses of TPE films, NP kinds, and doping mass. After being composited with a Cu NP-doped TPE film, the TPE composite fabric exhibited superior elastic behavior and good bending property, along with excellent flexibility. Moreover, a maximum output voltage of 470 V, a current of 24 μA, and a power of 12 mW under 3 MΩ can be achieved by applying a force of 60 N on the TF-TENG. More importantly, the TF-TENG can be successfully used to harvest biomechanical energy from human body and provides much more comfort. In general, the TF-TENG has great application prospects in sustainable wearable devices owing to its lightweight, flexibility, and high mechanical properties.

High density pixel array

NASA Technical Reports Server (NTRS)

McFall, James Earl (Inventor); Wiener-Avnear, Eliezer (Inventor)

2004-01-01

A pixel array device is fabricated by a laser micro-milling method under strict process control conditions. The device has an array of pixels bonded together with an adhesive filling the grooves between adjacent pixels. The array is fabricated by moving a substrate relative to a laser beam of predetermined intensity at a controlled, constant velocity along a predetermined path defining a set of grooves between adjacent pixels so that a predetermined laser flux per unit area is applied to the material, and repeating the movement for a plurality of passes of the laser beam until the grooves are ablated to a desired depth. The substrate is of an ultrasonic transducer material in one example for fabrication of a 2D ultrasonic phase array transducer. A substrate of phosphor material is used to fabricate an X-ray focal plane array detector.

Dye based photodiodes for solar energy applications

NASA Astrophysics Data System (ADS)

Mensah-Darkwa, K.; Ocaya, R.; Dere, A.; Al-Sehemi, Abdullah G.; Al-Ghamdi, Ahmed A.; Soylu, M.; Gupta, R. K.; Yakuphanoglu, F.

2017-10-01

Coumarin (CO) doped methylene blue (MB) organic photo-devices were fabricated. The CO-doped MB (0.00, 0.01, 0.03, 0.05, 0.1 wt% CO) were coated onto the surface of a p-type Si substrate by drop casting method. Some electrical parameters of the devices have been examined by current-voltage ( I- V), capacitance-voltage ( C- V), and conductance-voltage ( G- V) measurements. The fabricated devices had excellent rectifying properties. The diode exhibits a non-ideal diode behavior due to the series resistance and interface layer. The ideality factor, the barrier height, and the series resistance values of the diode as a function of doping and light illumination have been estimated using modified Cheung-Cheung and Norde's method. The highest I photo/ I dark photosensitivity of 5606 was observed for the diode having 0.01 CO doping at 100 mW/cm2 under -3 V. Furthermore, change of capacitance and conductance measurements with frequency is related to the existence of interface states. A maximum power conversion efficiency of 2.4% is estimated for the fabricated devices. The results reveal that coumarin-doped methylene blue/ p-Si heterojunction can be used as a photodiode in optoelectronic applications. It is also usable in low-power photovoltaic applications.

Defense Small Business Innovation Research Program (SBIR) FY 1984.

DTIC Science & Technology

1984-01-12

nuclear submarine non-metallic, light weight, high strength piping . Includes the development of adequate fabrication procedures for attaching pipe ...waste heat economizer methods, require development. Improved conventional and hybrid heat pipes and/or two phase transport devices 149 IF are required...DESCRIPTION: A need exists to conceive, design, fabricate and test a method of adjusting the length of the individual legs of nylon or Kevlar rope sling

Soft Lithographic Procedure for Producing Plastic Microfluidic Devices with View-ports Transparent to Visible and Infrared Light.

PubMed

Suryana, Mona; Shanmugarajah, Jegan V; Maniam, Sivakumar M; Grenci, Gianluca

2017-08-17

Infrared (IR) spectro-microscopy of living biological samples is hampered by the absorption of water in the mid-IR range and by the lack of suitable microfluidic devices. Here, a protocol for the fabrication of plastic microfluidic devices is demonstrated, where soft lithographic techniques are used to embed transparent Calcium Fluoride (CaF2) view-ports in connection with observation chamber(s). The method is based on a replica casting approach, where a polydimethylsiloxane (PDMS) mold is produced through standard lithographic procedures and then used as the template to produce a plastic device. The plastic device features ultraviolet/visible/infrared (UV/Vis/IR) -transparent windows made of CaF2 to allow for direct observation with visible and IR light. The advantages of the proposed method include: a reduced need for accessing a clean room micro-fabrication facility, multiple view-ports, an easy and versatile connection to an external pumping system through the plastic body, flexibility of the design, e.g., open/closed channels configuration, and the possibility to add sophisticated features such as nanoporous membranes.

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

Bachman, Daniel; Chen, Zhijiang; Wang, Christopher

Phase errors caused by fabrication variations in silicon photonic integrated circuits are an important problem, which negatively impacts device yield and performance. This study reports our recent progress in the development of a method for permanent, postfabrication phase error correction of silicon photonic circuits based on femtosecond laser irradiation. Using beam shaping technique, we achieve a 14-fold enhancement in the phase tuning resolution of the method with a Gaussian-shaped beam compared to a top-hat beam. The large improvement in the tuning resolution makes the femtosecond laser method potentially useful for very fine phase trimming of silicon photonic circuits. Finally, wemore » also show that femtosecond laser pulses can directly modify silicon photonic devices through a SiO 2 cladding layer, making it the only permanent post-fabrication method that can tune silicon photonic circuits protected by an oxide cladding.« less

Micro knife-edge optical measurement device in a silicon-on-insulator substrate.

PubMed

Chiu, Yi; Pan, Jiun-Hung

2007-05-14

The knife-edge method is a commonly used technique to characterize the optical profiles of laser beams or focused spots. In this paper, we present a micro knife-edge scanner fabricated in a silicon-on-insulator substrate using the micro-electromechanical-system technology. A photo detector can be fabricated in the device to allow further integration with on-chip signal conditioning circuitry. A novel backside deep reactive ion etching process is proposed to solve the residual stress effect due to the buried oxide layer. Focused optical spot profile measurement is demonstrated.

A thermophone on porous polymeric substrate

NASA Astrophysics Data System (ADS)

Chitnis, G.; Kim, A.; Song, S. H.; Jessop, A. M.; Bolton, J. S.; Ziaie, B.

2012-07-01

In this Letter, we present a simple, low-temperature method for fabricating a wide-band (>80 kHz) thermo-acoustic sound generator on a porous polymeric substrate. We were able to achieve up to 80 dB of sound pressure level with an input power of 0.511 W. No significant surface temperature increase was observed in the device even at an input power level of 2.5 W. Wide-band ultrasonic performance, simplicity of structure, and scalability of the fabrication process make this device suitable for many ranging and imaging applications.

Waveguide device and method for making same

DOEpatents

Forman, Michael A [San Francisco, CA

2007-08-14

A monolithic micromachined waveguide device or devices with low-loss, high-power handling, and near-optical frequency ranges is set forth. The waveguide and integrated devices are capable of transmitting near-optical frequencies due to optical-quality sidewall roughness. The device or devices are fabricated in parallel, may be mass produced using a LIGA manufacturing process, and may include a passive component such as a diplexer and/or an active capping layer capable of particularized signal processing of the waveforms propagated by the waveguide.

A practical topological insulator saturable absorber for mode-locked fiber laser

PubMed Central

Yan, Peiguang; Lin, Rongyong; Ruan, Shuangchen; Liu, Aijiang; Chen, Hao; Zheng, Yuequn; Chen, Sifan; Guo, Chunyu; Hu, Juguang

2015-01-01

A novel saturable absorber (SA) was fabricated by coating the topological insulator (TI) film on microfiber using pulsed laser deposition (PLD) method. The TISA device had an insertion loss of ~1.25 dB, a saturable intensity of 26.7 MW/cm2, a modulation depth of ~5.7%, and a nonsaturable loss of 20.5%. Upon employing this SA device, we established a passively mode-locked EDFL and achieved nearly free-chirped soliton pulse with 286 fs of pulse duration and >73 dB of signal to noise ratio (SNR). This result clearly evidences that the PLD is an effective scheme for practical SA device fabrication. PMID:25732598

Digital fabrication of textiles: an analysis of electrical networks in 3D knitted functional fabrics

NASA Astrophysics Data System (ADS)

Vallett, Richard; Knittel, Chelsea; Christe, Daniel; Castaneda, Nestor; Kara, Christina D.; Mazur, Krzysztof; Liu, Dani; Kontsos, Antonios; Kim, Youngmoo; Dion, Genevieve

2017-05-01

Digital fabrication methods are reshaping design and manufacturing processes through the adoption of pre-production visualization and analysis tools, which help minimize waste of materials and time. Despite the increasingly widespread use of digital fabrication techniques, comparatively few of these advances have benefited the design and fabrication of textiles. The development of functional fabrics such as knitted touch sensors, antennas, capacitors, and other electronic textiles could benefit from the same advances in electrical network modeling that revolutionized the design of integrated circuits. In this paper, the efficacy of using current state-of-the-art digital fabrication tools over the more common trialand- error methods currently used in textile design is demonstrated. Gaps are then identified in the current state-of-the-art tools that must be resolved to further develop and streamline the rapidly growing field of smart textiles and devices, bringing textile production into the realm of 21st century manufacturing.

Manufacture of patient-specific vascular replicas for endovascular simulation using fast, low-cost method

NASA Astrophysics Data System (ADS)

Kaneko, Naoki; Mashiko, Toshihiro; Ohnishi, Taihei; Ohta, Makoto; Namba, Katsunari; Watanabe, Eiju; Kawai, Kensuke

2016-12-01

Patient-specific vascular replicas are essential to the simulation of endovascular treatment or for vascular research. The inside of silicone replica is required to be smooth for manipulating interventional devices without resistance. In this report, we demonstrate the fabrication of patient-specific silicone vessels with a low-cost desktop 3D printer. We show that the surface of an acrylonitrile butadiene styrene (ABS) model printed by the 3D printer can be smoothed by a single dipping in ABS solvent in a time-dependent manner, where a short dip has less effect on the shape of the model. The vascular mold is coated with transparent silicone and then the ABS mold is dissolved after the silicone is cured. Interventional devices can pass through the inside of the smoothed silicone vessel with lower pushing force compared to the vessel without smoothing. The material cost and time required to fabricate the silicone vessel is about USD $2 and 24 h, which is much lower than the current fabrication methods. This fast and low-cost method offers the possibility of testing strategies before attempting particularly difficult cases, while improving the training of endovascular therapy, enabling the trialing of new devices, and broadening the scope of vascular research.

All-dielectric perforated metamaterials with toroidal dipolar response (Conference Presentation)

NASA Astrophysics Data System (ADS)

Stenishchev, Ivan; Basharin, Alexey A.

2017-05-01

We present metamaterials based on dielectric slab with perforated identical cylindrical clusters with perforated holes, which allow to support the toroidal dipolar response due to Mie-resonances in each hole. Note that proposed metamaterial is technologically simple for fabrication in optical frequency range. Metamaterial can be fabricated by several methods. For instance, we may apply the molecular beam epitaxy method for deposition of Si or GaAs layers, which have permittivity close to 16. Next step, nanometer/micrometer holes are perforated by focused ion beam method or laser cutting method. Fundamental difference of proposed metamaterial is technological fabrication process. Classically all- dielectric optical metamaterials consist of nano-spheres or nano-discs, which are complicated for fabrication, while our idea and suggested metamaterials are promising prototype of various optical/THz all-dielectic devices as sensor, nano-antennas elements for nanophotonics.

Environmentally-assisted technique for transferring devices onto non-conventional substrates

DOEpatents

Lee, Chi-Hwan; Kim, Dong Rip; Zheng, Xiaolin

2014-08-26

A device fabrication method includes: (1) providing a growth substrate including a base and an oxide layer disposed over the base; (2) forming a metal layer over the oxide layer; (3) forming a stack of device layers over the metal layer; (4) performing interfacial debonding of the metal layer to separate the stack of device layers and the metal layer from the growth substrate; and (5) affixing the stack of device layers to a target substrate.

3D printed microfluidics for biological applications.

PubMed

Ho, Chee Meng Benjamin; Ng, Sum Huan; Li, King Ho Holden; Yoon, Yong-Jin

2015-01-01

The term "Lab-on-a-Chip," is synonymous with describing microfluidic devices with biomedical applications. Even though microfluidics have been developing rapidly over the past decade, the uptake rate in biological research has been slow. This could be due to the tedious process of fabricating a chip and the absence of a "killer application" that would outperform existing traditional methods. In recent years, three dimensional (3D) printing has been drawing much interest from the research community. It has the ability to make complex structures with high resolution. Moreover, the fast building time and ease of learning has simplified the fabrication process of microfluidic devices to a single step. This could possibly aid the field of microfluidics in finding its "killer application" that will lead to its acceptance by researchers, especially in the biomedical field. In this paper, a review is carried out of how 3D printing helps to improve the fabrication of microfluidic devices, the 3D printing technologies currently used for fabrication and the future of 3D printing in the field of microfluidics.

Aluminium alloyed iron-silicide/silicon solar cells: A simple approach for low cost environmental-friendly photovoltaic technology.

PubMed

Kumar Dalapati, Goutam; Masudy-Panah, Saeid; Kumar, Avishek; Cheh Tan, Cheng; Ru Tan, Hui; Chi, Dongzhi

2015-12-03

This work demonstrates the fabrication of silicide/silicon based solar cell towards the development of low cost and environmental friendly photovoltaic technology. A heterostructure solar cells using metallic alpha phase (α-phase) aluminum alloyed iron silicide (FeSi(Al)) on n-type silicon is fabricated with an efficiency of 0.8%. The fabricated device has an open circuit voltage and fill-factor of 240 mV and 60%, respectively. Performance of the device was improved by about 7 fold to 5.1% through the interface engineering. The α-phase FeSi(Al)/silicon solar cell devices have promising photovoltaic characteristic with an open circuit voltage, short-circuit current and a fill factor (FF) of 425 mV, 18.5 mA/cm(2), and 64%, respectively. The significant improvement of α-phase FeSi(Al)/n-Si solar cells is due to the formation p(+-)n homojunction through the formation of re-grown crystalline silicon layer (~5-10 nm) at the silicide/silicon interface. Thickness of the regrown silicon layer is crucial for the silicide/silicon based photovoltaic devices. Performance of the α-FeSi(Al)/n-Si solar cells significantly depends on the thickness of α-FeSi(Al) layer and process temperature during the device fabrication. This study will open up new opportunities for the Si based photovoltaic technology using a simple, sustainable, and los cost method.

Cost Effective Paper-Based Colorimetric Microfluidic Devices and Mobile Phone Camera Readers for the Classroom

ERIC Educational Resources Information Center

Koesdjojo, Myra T.; Pengpumkiat, Sumate; Wu, Yuanyuan; Boonloed, Anukul; Huynh, Daniel; Remcho, Thomas P.; Remcho, Vincent T.

2015-01-01

We have developed a simple and direct method to fabricate paper-based microfluidic devices that can be used for a wide range of colorimetric assay applications. With these devices, assays can be performed within minutes to allow for quantitative colorimetric analysis by use of a widely accessible iPhone camera and an RGB color reader application…

Micro-opto-mechanical devices and systems using epitaxial lift off

NASA Technical Reports Server (NTRS)

Camperi-Ginestet, C.; Kim, Young W.; Wilkinson, S.; Allen, M.; Jokerst, N. M.

1993-01-01

The integration of high quality, single crystal thin film gallium arsenide (GaAs) and indium phosphide (InP) based photonic and electronic materials and devices with host microstructures fabricated from materials such as silicon (Si), glass, and polymers will enable the fabrication of the next generation of micro-opto-mechanical systems (MOMS) and optoelectronic integrated circuits. Thin film semiconductor devices deposited onto arbitrary host substrates and structures create hybrid (more than one material) near-monolithic integrated systems which can be interconnected electrically using standard inexpensive microfabrication techniques such as vacuum metallization and photolithography. These integrated systems take advantage of the optical and electronic properties of compound semiconductor devices while still using host substrate materials such as silicon, polysilicon, glass and polymers in the microstructures. This type of materials optimization for specific tasks creates higher performance systems than those systems which must use trade-offs in device performance to integrate all of the function in a single material system. The low weight of these thin film devices also makes them attractive for integration with micromechanical devices which may have difficulty supporting and translating the full weight of a standard device. These thin film devices and integrated systems will be attractive for applications, however, only when the development of low cost, high yield fabrication and integration techniques makes their use economically feasible. In this paper, we discuss methods for alignment, selective deposition, and interconnection of thin film epitaxial GaAs and InP based devices onto host substrates and host microstructures.

Homogeneous-oxide stack in IGZO thin-film transistors for multi-level-cell NAND memory application

NASA Astrophysics Data System (ADS)

Ji, Hao; Wei, Yehui; Zhang, Xinlei; Jiang, Ran

2017-11-01

A nonvolatile charge-trap-flash memory that is based on amorphous indium-gallium-zinc-oxide thin film transistors was fabricated with a homogeneous-oxide structure for a multi-level-cell application. All oxide layers, i.e., tunneling layer, charge trapping layer, and blocking layer, were fabricated with Al2O3 films. The fabrication condition (including temperature and deposition method) of the charge trapping layer was different from those of the other oxide layers. This device demonstrated a considerable large memory window of 4 V between the states fully erased and programmed with the operation voltage less than 14 V. This kind of device shows a good prospect for multi-level-cell memory applications.

Electra-optical device including a nitrogen containing electrolyte

DOEpatents

Bates, John B.; Dudney, Nancy J.; Gruzalski, Greg R.; Luck, Christopher F.

1995-01-01

Described is a thin-film battery, especially a thin-film microbattery, and a method for making same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode Configured as a microbattery, the battery can be fabricated directly onto a semiconductor chip, onto the semiconductor die or onto any portion of the chip carrier. The battery can be fabricated to any specified size or shape to meet the requirements of a particular application. The battery is fabricated of solid state materials and is capable of operation between -15.degree. C. and 150.degree. C.

Coupling of carboxylic groups onto the surface of polystyrene parts during fused filament fabrication

NASA Astrophysics Data System (ADS)

Nagel, Jürgen; Zimmermann, Philipp; Schubert, Oliver; Simon, Frank; Schlenstedt, Kornelia

2017-11-01

A method for the fabrication of polystyrene parts, modified with carboxylic groups during Fused Filament Fabrication (FFF), is being introduced. This method is based on the application of a thin layer of a reactive polymer carrying carboxylic groups on a substrate surface. A polystyrene film is printed on top of this layer. During contact between the hot melt and the reactive layer, a Friedel-Crafts type acylation using a green catalyst takes place, which attaches the reactive polymer to the polystyrene surface. The modified surface is homogeneous, hydrophilic and able to bind copper ions. The method could be used to fabricate unique parts of polystyrene with tailored surface functionalisation. It could be applied for laboratory use, e.g. for the manufacture of lab-on-a-chip devices.

Fabrication of sub-12 nm thick silicon nanowires by processing scanning probe lithography masks

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

Kyoung Ryu, Yu; Garcia, Ricardo, E-mail: r.garcia@csic.es; Aitor Postigo, Pablo

2014-06-02

Silicon nanowires are key elements to fabricate very sensitive mechanical and electronic devices. We provide a method to fabricate sub-12 nm silicon nanowires in thickness by combining oxidation scanning probe lithography and anisotropic dry etching. Extremely thin oxide masks (0.3–1.1 nm) are transferred into nanowires of 2–12 nm in thickness. The width ratio between the mask and the silicon nanowire is close to one which implies that the nanowire width is controlled by the feature size of the nanolithography. This method enables the fabrication of very small single silicon nanowires with cross-sections below 100 nm{sup 2}. Those values are the smallest obtained withmore » a top-down lithography method.« less

Evaluation of a low-cost commercially available extraction device for assessing lead bioaccessibility in contaminated soils.

PubMed

Nelson, Clay M; Gilmore, Thomas M; Harrington, M; Scheckel, Kirk G; Miller, Bradley W; Bradham, Karen D

2013-03-01

The U.S. EPA's in vitro bioaccessibility (IVBA) method 9200.1-86 defines a validated analytical procedure for the determination of lead bioaccessibility in contaminated soils. The method requires the use of a custom-fabricated extraction device that uses a heated water bath for sample incubation. In an effort to improve ease of use, increase sample throughput, and reduce equipment acquisition and maintenance costs, an alternative low-cost, commercially available extraction device capable of sample incubation via heated air and end-over-end rotation was evaluated. An intra-laboratory study was conducted to compare lead bioaccessibility values derived using the two extraction devices. IVBA values were not statistically different (α = 0.05) between the two extraction devices for any of the soils (n = 6) evaluated in this study, with an average difference in mean lead IVBA of 0.8% (s.d. = 0.5%). The commercially available extraction device was able to generate accurate lead IVBA data as compared to the U.S. EPA's expected value for a National Institute of Standards and Technology standard reference material soil. The relative percent differences between high and low IVBA values for each soil, a measure of instrument precision, were also not statistically different (α = 0.05) between the two extraction devices. The statistical agreement of lead IVBA values observed using the two extraction devices supports the use of a low-cost, commercially available extraction device as a reliable alternative to a custom-fabricated device as required by EPA method 9200.1-86.

Device-packaging method and apparatus for optoelectronic circuits

DOEpatents

Zortman, William A.; Henry, Michael David; Jarecki, Jr., Robert L.

2017-04-25

An optoelectronic device package and a method for its fabrication are provided. The device package includes a lid die and an active die that is sealed or sealable to the lid die and in which one or more optical waveguides are integrally defined. The active die includes one or more active device regions, i.e. integral optoelectronic devices or etched cavities for placement of discrete optoelectronic devices. Optical waveguides terminate at active device regions so that they can be coupled to them. Slots are defined in peripheral parts of the active dies. At least some of the slots are aligned with the ends of integral optical waveguides so that optical fibers or optoelectronic devices inserted in the slots can optically couple to the waveguides.

Fabrication and RF characterization of a single nickel silicide nanowire for an interconnect.

PubMed

Lee, Dongjin; Kang, Myunggil; Hong, Suheon; Hwang, Donghoon; Heo, Keun; Joo, Won-Jae; Kim, Sangsig; Whang, Dongmok; Hwang, Sung Woo

2013-09-01

We fabricated a nickel silicide nanowire (NiSi NW) device with a low thermal budget and characterized it by measuring the S-parameters in the radio-frequency (RF) regime. A single silicon nanowire (Si NW) was assembled on a substrate with a two-port coplanar waveguide structure using the dielectrophoresis method. Then, the Si NW on the device was perfectly transformed into a NiSi NW. The NiSi NW device was characterized by performing measurements in the DC and RF regimes. The transformation into the NiSi NW resulted in reducing about three-order more the resistance than before the transformation. Hence, the transmission of the NiSi NW device was 25 dB higher than that of the Si NW device up to gigahertz. We also discussed extracting the intrinsic properties of the NiSi NW by using de-embedding, circuit modeling, and simulation.

Paper-based ion concentration polarization device for selective preconcentration of muc1 and lamp-2 genes

NASA Astrophysics Data System (ADS)

Son, Seok Young; Lee, Hyomin; Kim, Sung Jae

2017-12-01

Recently, novel biomolecules separation and detection methods based on ion concentration polarization (ICP) phenomena have been extensively researched due to its high amplification ratio and high-speed accumulation. Despite of these bright advances, the fabrication of conventional ICP devices still have complicated and times-consuming tasks. As an alternative platform, a paper have been recently used for the identical ICP operations. In this work, we demonstrated the selective preconcentration of a muc1 gene fragment as human breast cancer marker and a lamp-2 gene fragment as the cause of Danon disease in paper-based ICP devices. As a result, these two DNA fragments were successfully concentrated up to 60 fold at different location in a single paper-channel. The device would be a promising platform for point-of-care device due to an economic fabrication, the easy extraction of concentrated sample and an easy disposability.

Flexible bottom-gate graphene transistors on Parylene C substrate and the effect of current annealing

PubMed Central

Kim, Hyungsoo; Bong, Jihye; Mikael, Solomon; Kim, Tong June; Williams, Justin C.; Ma, Zhenqiang

2016-01-01

Flexible graphene transistors built on a biocompatible Parylene C substrate would enable active circuitry to be integrated into flexible implantable biomedical devices. An annealing method to improve the performance of a flexible transistor without damaging the flexible substrate is also desirable. Here, we present a fabrication method of a flexible graphene transistor with a bottom-gate coplanar structure on a Parylene C substrate. Also, a current annealing method and its effect on the device performance have been studied. The localized heat generated by the current annealing method improves the drain current, which is attributed to the decreased contact resistance between graphene and S/D electrodes. A maximum current annealing power in the Parylene C-based graphene transistor has been extracted to provide a guideline for an appropriate current annealing. The fabricated flexible graphene transistor shows a field-effect mobility, maximum transconductance, and a Ion/Ioff ratio of 533.5 cm2/V s, 58.1 μS, and 1.76, respectively. The low temperature process and the current annealing method presented here would be useful to fabricate two-dimensional materials-based flexible electronics. PMID:27795570

Organic crystalline films for optical applications and related methods of fabrication

NASA Technical Reports Server (NTRS)

Leyderman, Alexander (Inventor); Cui, Yunlong (Inventor)

2003-01-01

The present invention provides organic single crystal films of less than 20 .mu.m, and devices and methods of making such films. The crystal films are useful in electro-optical applications and can be provided as part of an electro-optical device which provides strength, durability, and relative ease of manipulation of the mono-crystalline films during and after crystal growth.

Post polymerization cure shape memory polymers

DOEpatents

Wilson, Thomas S.; Hearon, II, Michael Keith; Bearinger, Jane P.

2017-01-10

This invention relates to chemical polymer compositions, methods of synthesis, and fabrication methods for devices regarding polymers capable of displaying shape memory behavior (SMPs) and which can first be polymerized to a linear or branched polymeric structure, having thermoplastic properties, subsequently processed into a device through processes typical of polymer melts, solutions, and dispersions and then crossed linked to a shape memory thermoset polymer retaining the processed shape.

Post polymerization cure shape memory polymers

DOEpatents

Wilson, Thomas S; Hearon, Michael Keith; Bearinger, Jane P

2014-11-11

This invention relates to chemical polymer compositions, methods of synthesis, and fabrication methods for devices regarding polymers capable of displaying shape memory behavior (SMPs) and which can first be polymerized to a linear or branched polymeric structure, having thermoplastic properties, subsequently processed into a device through processes typical of polymer melts, solutions, and dispersions and then crossed linked to a shape memory thermoset polymer retaining the processed shape.

Biological implications of lab-on-a-chip devices fabricated using multi-jet modelling and stereolithography processes

NASA Astrophysics Data System (ADS)

Zhu, Feng; Macdonald, Niall; Skommer, Joanna; Wlodkowic, Donald

2015-06-01

Current microfabrication methods are often restricted to two-dimensional (2D) or two and a half dimensional (2.5D) structures. Those fabrication issues can be potentially addressed by emerging additive manufacturing technologies. Despite rapid growth of additive manufacturing technologies in tissue engineering, microfluidics has seen relatively little developments with regards to adopting 3D printing for rapid fabrication of complex chip-based devices. This has been due to two major factors: lack of sufficient resolution of current rapid-prototyping methods (usually >100 μm ) and optical transparency of polymers to allow in vitro imaging of specimens. We postulate that adopting innovative fabrication processes can provide effective solutions for prototyping and manufacturing of chip-based devices with high-aspect ratios (i.e. above ration of 20:1). This work provides a comprehensive investigation of commercially available additive manufacturing technologies as an alternative for rapid prototyping of complex monolithic Lab-on-a-Chip devices for biological applications. We explored both multi-jet modelling (MJM) and several stereolithography (SLA) processes with five different 3D printing resins. Compared with other rapid prototyping technologies such as PDMS soft lithography and infrared laser micromachining, we demonstrated that selected SLA technologies had superior resolution and feature quality. We also for the first time optimised the post-processing protocols and demonstrated polymer features under scanning electronic microscope (SEM). Finally we demonstrate that selected SLA polymers have optical properties enabling high-resolution biological imaging. A caution should be, however, exercised as more work is needed to develop fully bio-compatible and non-toxic polymer chemistries.

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

PubMed Central

Jung, Han Sae; Tsai, Hsin-Zon; Wong, Dillon; Germany, Chad; Kahn, Salman; Kim, Youngkyou; Aikawa, Andrew S.; Desai, Dhruv K.; Rodgers, Griffin F.; Bradley, Aaron J.; Velasco, Jairo; Watanabe, Kenji; Taniguchi, Takashi; Wang, Feng; Zettl, Alex; Crommie, Michael F.

2015-01-01

Owing to its relativistic low-energy charge carriers, the interaction between graphene and various impurities leads to a wealth of new physics and degrees of freedom to control electronic devices. In particular, the behavior of graphene’s charge carriers in response to potentials from charged Coulomb impurities is predicted to differ significantly from that of most materials. Scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) can provide detailed information on both the spatial and energy dependence of graphene's electronic structure in the presence of a charged impurity. The design of a hybrid impurity-graphene device, fabricated using controlled deposition of impurities onto a back-gated graphene surface, has enabled several novel methods for controllably tuning graphene’s electronic properties.1-8 Electrostatic gating enables control of the charge carrier density in graphene and the ability to reversibly tune the charge2 and/or molecular5 states of an impurity. This paper outlines the process of fabricating a gate-tunable graphene device decorated with individual Coulomb impurities for combined STM/STS studies.2-5 These studies provide valuable insights into the underlying physics, as well as signposts for designing hybrid graphene devices. PMID:26273961

Material-Independent Nanotransfer onto a Flexible Substrate Using Mechanical-Interlocking Structure.

PubMed

Seo, Min-Ho; Choi, Seon-Jin; Park, Sang Hyun; Yoo, Jae-Young; Lim, Sung Kyu; Lee, Jae-Shin; Choi, Kwang-Wook; Jo, Min-Seung; Kim, Il-Doo; Yoon, Jun-Bo

2018-05-22

Nanowire-transfer technology has received much attention thanks to its capability to fabricate high-performance flexible nanodevices with high simplicity and throughput. However, it is still challenging to extend the conventional nanowire-transfer method to the fabrication of a wide range of devices since a chemical-adhesion-based nanowire-transfer mechanism is complex and time-consuming, hindering successful transfer of diverse nanowires made of various materials. Here, we introduce a material-independent mechanical-interlocking-based nanowire-transfer (MINT) method, fabricating ultralong and fully aligned nanowires on a large flexible substrate (2.5 × 2 cm 2 ) in a highly robust manner. For the material-independent nanotransfer, we developed a mechanics-based nanotransfer method, which employs a dry-removable amorphous carbon (a-C) sacrificial layer between a vacuum-deposited nanowire and the underlying master mold. The controlled etching of the sacrificial layer enables the formation of a mechanical-interlocking structure under the nanowire, facilitating peeling off of the nanowire from the master mold robustly and reliably. Using the developed MINT method, we successfully fabricated various metallic and semiconductor nanowire arrays on flexible substrates. We further demonstrated that the developed method is well suited to the reliable fabrication of highly flexible and high-performance nanoelectronic devices. As examples, a fully aligned gold (Au) microheater array exhibited high bending stability (10 6 cycling) and ultrafast (∼220 ms) heating operation up to ∼100 °C. An ultralong Au heater-embedded cuprous-oxide (Cu 2 O) nanowire chemical gas sensor showed significantly improved reversible reaction kinetics toward NO 2 with 10-fold enhancement in sensitivity at 100 °C.

Thermal ink-jet device using single-chip silicon microchannels

NASA Astrophysics Data System (ADS)

Wuu, DongSing; Cheng, Chen-Yue; Horng, RayHua; Chan, G. C.; Chiu, Sao-Ling; Wu, Yi-Yung

1998-06-01

We present a new method to fabricate silicon microfluidic channels by through-hole etching with subsequent planarization. The method is based on etching out the deep grooves through a perforated silicon carbide membrane, followed by sealing the membrane with plasma-enhanced chemical vapor deposition (PECVD). Low-pressure-chemical-vapor- deposited (LPCVD) polysilicon was used as a sacrificial layer to define the channel structure and only one etching step is required. This permits the realization of planarization after a very deep etching step in silicon and offers the possibility for film deposition, resist spinning and film patterning across deep grooves. The process technology was demonstrated on the fabrication of a monolithic silicon microchannel structure for thermal inkjet printing. The Ta-Al heater arrays are integrated on the top of each microchannel, which connect to a common on-chip front-end ink reservoir. The fabrication of this device requires six masks and no active nozzle-to-chip alignment. Moreover, the present micromachining process is compatible with the addition of on-chip circuitry for multiplexing the heater control signals. Heat transfer efficiency to the ink is enhanced by the high thermal conductivity of the silicon carbide in the channel ceiling, while the bulk silicon maintains high interchannel isolation. The fabricated inkjet devices show the droplet sizes of 20 - 50 micrometer in diameter with various channel dimensions and stable ejection of ink droplets more than 1 million.

Complaint liquid metal electrodes for dielectric elastomer actuators

NASA Astrophysics Data System (ADS)

Finkenauer, Lauren R.; Majidi, Carmel

2014-03-01

This work presents a liquid-phase metal electrode to be used with poly(dimethylsiloxane) (PDMS) for a dielectric elastomer actuator (DEA). DEAs are favorable for soft-matter applications where high efficiency and response times are desirable. A consistent challenge faced during the fabrication of these devices is the selection and deposition of electrode material. While numerous designs have been demonstrated with a variety of conductive elastomers and greases, these materials have significant and often intrinsic shortcomings, e.g. low conductivity, hysteresis, incapability of large deformations, and complex fabrication requirements. The liquid metal alloy eutectic Gallium-Indium (EGaIn) is a promising alternative to existing compliant electrodes, having both high conductivity and complete soft-matter functionality. The liquid electrode shares almost the same electrical conductivity as conventional metal wiring and provides no mechanical resistance to bending or stretching of the DEA. This research establishes a straightforward and effective method for quickly depositing EGaIn electrodes, which can be adapted for batch fabrication, and demonstrates the successful actuation of sample curved cantilever elastomer actuators using these electrodes. As with the vast majority of electrostatically actuated elastomer devices, the voltage requirements for these curved DEAs are still quite significant, though modifications to the fabrication process show some improved electrical properties. The ease and speed with which this method can be implemented suggests that the development of a more electronically efficient device is realistic and worthwhile.

ZnO nanodisk based UV detectors with printed electrodes.

PubMed

Alenezi, Mohammad R; Alshammari, Abdullah S; Alzanki, Talal H; Jarowski, Peter; Henley, Simon John; Silva, S Ravi P

2014-04-08

The fabrication of highly functional materials for practical devices requires a deep understanding of the association between morphological and structural properties and applications. A controlled hydrothermal method to produce single crystal ZnO hexagonal nanodisks, nanorings, and nanoroses using a mixed solution of zinc sulfate (ZnSO4) and hexamethylenetetramine (HMTA) without the need of catalysts, substrates, or templates at low temperature (75 °C) is introduced. Metal-semiconductor-metal (MSM) ultraviolet (UV) detectors were fabricated based on individual and multiple single-crystal zinc oxide (ZnO) hexagonal nanodisks. High quality single crystal individual nanodisk devices were fabricated with inkjet-printed silver electrodes. The detectors fabricated show record photoresponsivity (3300 A/W) and external quantum efficiency (1.2 × 10(4)), which we attribute to the absence of grain boundaries in the single crystal ZnO nanodisk and the polarity of its exposed surface.

P and n-type microcrystalline semiconductor alloy material including band gap widening elements, devices utilizing same

DOEpatents

Guha, Subhendu; Ovshinsky, Stanford R.

1988-10-04

An n-type microcrystalline semiconductor alloy material including a band gap widening element; a method of fabricating p-type microcrystalline semiconductor alloy material including a band gap widening element; and electronic and photovoltaic devices incorporating said n-type and p-type materials.

GaN Nanowire Devices: Fabrication and Characterization

NASA Astrophysics Data System (ADS)

Scott, Reum

The development of microelectronics in the last 25 years has been characterized by an exponential increase of the bit density in integrated circuits (ICs) with time. Scaling solid-state devices improves cost, performance, and power; as such, it is of particular interest for companies, who gain a market advantage with the latest technology. As a result, the microelectronics industry has driven transistor feature size scaling from 10 μm to ~30 nm during the past 40 years. This trend has persisted for 40 years due to optimization, new processing techniques, device structures, and materials. But when noting processor speeds from the 1970's to 2009 and then again in 2010, the implication would be that the trend has ceased. To address the challenge of shrinking the integrated circuit (IC), current research is centered on identifying new materials and devices that can supplement and/or potentially supplant it. Bottom-up methods tailor nanoscale building blocks---atoms, molecules, quantum dots, and nanowires (NWs)---to be used to overcome these limitations. The Group IIIA nitrides (InN, AlN, and GaN) possess appealing properties such as a direct band gap spanning the whole solar spectrum, high saturation velocity, and high breakdown electric field. As a result nanostructures and nanodevices made from GaN and related nitrides are suitable candidates for efficient nanoscale UV/ visible light emitters, detectors, and gas sensors. To produce devices with such small structures new fabrication methods must be implemented. Devices composed of GaN nanowires were fabricated using photolithography and electron beam lithography. The IV characteristics of these devices were noted under different illuminations and the current tripled from 4.8*10-7 A to 1.59*10 -6 A under UV light which persisted for at least 5hrs.

Printable Fabrication of Nanocoral-Structured Electrodes for High-Performance Flexible and Planar Supercapacitor with Artistic Design.

PubMed

Lin, Yuanjing; Gao, Yuan; Fan, Zhiyong

2017-11-01

Planar supercapacitors with high flexibility, desirable operation safety, and high performance are considered as attractive candidates to serve as energy-storage devices for portable and wearable electronics. Here, a scalable and printable technique is adopted to construct novel and unique hierarchical nanocoral structures as the interdigitated electrodes on flexible substrates. The as-fabricated flexible all-solid-state planar supercapacitors with nanocoral structures achieve areal capacitance up to 52.9 mF cm -2 , which is 2.5 times that of devices without nanocoral structures, and this figure-of-merit is among the highest in the literature for the same category of devices. More interestingly, due to utilization of the inkjet-printing technique, excellent versatility on electrode-pattern artistic design is achieved. Particularly, working supercapacitors with artistically designed patterns are demonstrated. Meanwhile, the high scalability of such a printable method is also demonstrated by fabrication of large-sized artistic supercapacitors serving as energy-storage devices in a wearable self-powered system as a proof of concept. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structurally Engineered Nanoporous Ta2O5-x Selector-Less Memristor for High Uniformity and Low Power Consumption.

PubMed

Kwon, Soonbang; Kim, Tae-Wook; Jang, Seonghoon; Lee, Jae-Hwang; Kim, Nam Dong; Ji, Yongsung; Lee, Chul-Ho; Tour, James M; Wang, Gunuk

2017-10-04

A memristor architecture based on metal-oxide materials would have great promise in achieving exceptional energy efficiency and higher scalability in next-generation electronic memory systems. Here, we propose a facile method for fabricating selector-less memristor arrays using an engineered nanoporous Ta 2 O 5-x architecture. The device was fabricated in the form of crossbar arrays, and it functions as a switchable rectifier with a self-embedded nonlinear switching behavior and ultralow power consumption (∼2.7 × 10 -6 W), which results in effective suppression of crosstalk interference. In addition, we determined that the essential switching elements, such as the programming power, the sneak current, the nonlinearity value, and the device-to-device uniformity, could be enhanced by in-depth structural engineering of the pores in the Ta 2 O 5-x layer. Our results, on the basis of the structural engineering of metal-oxide materials, could provide an attractive approach for fabricating simple and cost-efficient memristor arrays with acceptable device uniformity and low power consumption without the need for additional addressing selectors.

Designing of Hybrid Structured Glass Laminated Transparent Nano Composites through Vacuum infusion Technique

NASA Astrophysics Data System (ADS)

Mukherji, A.; Tarapure, N. D.; Wakure, G. N.

2017-05-01

Glass is the most commonly used transparent material. However, glass is not suitable in applications where low weight, high strength is required. The present invention comprises a method of making a Transparent Glass Laminated Nano composite product. The product contains a Bidirectionally oriented E-Glass Fabric an essentially bidirectional yarn woven fabrics is stretched Bidirectionally by specially fabricated steel frame associated with both co and counter rotating device. These fibers include glass fibrics/cloths or mixtures of any of these. The synthetic fiber may be any synthetic silica based oven waived bi-directional or Uni-directional fabrics. Engaged gear provided in the device develops uniform tension on fabric, in both direction. Nano particle dispersed resin to be used is formulated with their respective curing agents and extenders. The formulated resin contains 0.1-0.5% of Nano additives and the product composed from 5-10 % of Glass fabric, between 10 to 20 % of ordinary glass, and between 60-80 % of the product is the Nano particles dispersed formulated resin, all measured by volume.

3D direct writing fabrication of electrodes for electrochemical storage devices

NASA Astrophysics Data System (ADS)

Wei, Min; Zhang, Feng; Wang, Wei; Alexandridis, Paschalis; Zhou, Chi; Wu, Gang

2017-06-01

Among different printing techniques, direct ink writing is commonly used to fabricate 3D battery and supercapacitor electrodes. The major advantages of using the direct ink writing include effectively building 3D structure for energy storage devices and providing higher power density and higher energy density than traditional techniques due to the increased surface area of electrode. Nevertheless, direct ink writing has high standards for the printing inks, which requires high viscosity, high yield stress under shear and compression, and well-controlled viscoelasticity. Recently, a number of 3D-printed energy storage devices have been reported, and it is very important to understand the printing process and the ink preparation process for further material design and technology development. We discussed current progress of direct ink writing technologies by using various electrode materials including carbon nanotube-based material, graphene-based material, LTO (Li4Ti5O12), LFP (LiFePO4), LiMn1-xFexPO4, and Zn-based metallic oxide. Based on achieve electrochemical performance, these 3D-printed devices deliver performance comparable to the energy storage device fabricated using traditional methods still leaving large room for further improvement. Finally, perspectives are provided on the potential future direction of 3D printing for all solid-state electrochemical energy storage devices.

Vapor Grown Perovskite Solar Cells

NASA Astrophysics Data System (ADS)

Abdussamad Abbas, Hisham

Perovskite solar cells has been the fastest growing solar cell material till date with verified efficiencies of over 22%. Most groups in the world focuses their research on solution based devices that has residual solvent in the material bulk. This work focuses extensively on the fabrication and properties of vapor based perovskite devices that is devoid of solvents. The initial part of my work focuses on the detailed fabrication of high efficiency consistent sequential vapor NIP devices made using P3HT as P-type Type II heterojunction. The sequential vapor devices experiences device anomalies like voltage evolution and IV hysteresis owing to charge trapping in TiO2. Hence, sequential PIN devices were fabricated using doped Type-II heterojunctions that had no device anomalies. The sequential PIN devices has processing restriction, as organic Type-II heterojunction materials cannot withstand high processing temperature, hence limiting device efficiency. Thereby bringing the need of co-evaporation for fabricating high efficiency consistent PIN devices, the approach has no-restriction on substrates and offers stoichiometric control. A comprehensive description of the fabrication, Co-evaporator setup and how to build it is described. The results of Co-evaporated devices clearly show that grain size, stoichiometry and doped transport layers are all critical for eliminating device anomalies and in fabricating high efficiency devices. Finally, Formamidinium based perovskite were fabricated using sequential approach. A thermal degradation study was conducted on Methyl Ammonium Vs. Formamidinium based perovskite films, Formamidinium based perovskites were found to be more stable. Lastly, inorganic films such as CdS and Nickel oxide were developed in this work.

21 CFR 884.6140 - Assisted reproduction micropipette fabrication instruments.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Assisted reproduction micropipette fabrication... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6140 Assisted reproduction micropipette fabrication instruments. (a) Identification...

21 CFR 884.6140 - Assisted reproduction micropipette fabrication instruments.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction micropipette fabrication... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6140 Assisted reproduction micropipette fabrication instruments. (a) Identification...

Fabrication of a microfluidic chip by UV bonding at room temperature for integration of temperature-sensitive layers

NASA Astrophysics Data System (ADS)

Schlautmann, S.; Besselink, G. A. J.; Radhakrishna Prabhu, G.; Schasfoort, R. B. M.

2003-07-01

A method for the bonding of a microfluidic device at room temperature is presented. The wafer with the fluidic structures was bonded to a sensor wafer with gold pads by means of adhesive bonding, utilizing an UV-curable glue layer. To avoid filling the fluidic channels with the glue, a stamping process was developed which allows the selective application of a thin glue layer. In this way a microfluidic glass chip was fabricated that could be used for performing surface plasmon resonance measurements without signs of leakage. The advantage of this method is the possibility of integration of organic layers as well as other temperature-sensitive layers into a microfluidic glass device.

Methods for freeform fabrication of structures

DOEpatents

Kaufman, Stephen G.; Spletzer, Barry L.

2000-01-01

Rapid prototyping methods and apparatuses that produce structures made of continuous-fiber polymer-matrix composites without the use of molds. Instead of using molds, the composite structure is fabricated patch by patch in layers or wraps, using a two- or three-axis stage connected to a rapidly-reconfigurable forming surface, and a robot arm to position the evolving composite structure, which are both programmable devices. Because programmable devices are included, i.e., a robot and a two- or three-axis stage connected to the reconfigurable forming surface, the control program needed to produce a desired shape can be easily modified to automatically generate the desired shape from an electronic model (e.g., using a CAD/CAM system) of the desired (predetermined) shape.

Sub-diffraction Laser Synthesis of Silicon Nanowires

PubMed Central

Mitchell, James I.; Zhou, Nan; Nam, Woongsik; Traverso, Luis M.; Xu, Xianfan

2014-01-01

We demonstrate synthesis of silicon nanowires of tens of nanometers via laser induced chemical vapor deposition. These nanowires with diameters as small as 60 nm are produced by the interference between incident laser radiation and surface scattered radiation within a diffraction limited spot, which causes spatially confined, periodic heating needed for high resolution chemical vapor deposition. By controlling the intensity and polarization direction of the incident radiation, multiple parallel nanowires can be simultaneously synthesized. The nanowires are produced on a dielectric substrate with controlled diameter, length, orientation, and the possibility of in-situ doping, and therefore are ready for device fabrication. Our method offers rapid one-step fabrication of nano-materials and devices unobtainable with previous CVD methods. PMID:24469704

Postfabrication Phase Error Correction of Silicon Photonic Circuits by Single Femtosecond Laser Pulses

DOE PAGES

Bachman, Daniel; Chen, Zhijiang; Wang, Christopher; ...

2016-11-29

Phase errors caused by fabrication variations in silicon photonic integrated circuits are an important problem, which negatively impacts device yield and performance. This study reports our recent progress in the development of a method for permanent, postfabrication phase error correction of silicon photonic circuits based on femtosecond laser irradiation. Using beam shaping technique, we achieve a 14-fold enhancement in the phase tuning resolution of the method with a Gaussian-shaped beam compared to a top-hat beam. The large improvement in the tuning resolution makes the femtosecond laser method potentially useful for very fine phase trimming of silicon photonic circuits. Finally, wemore » also show that femtosecond laser pulses can directly modify silicon photonic devices through a SiO 2 cladding layer, making it the only permanent post-fabrication method that can tune silicon photonic circuits protected by an oxide cladding.« less

Fabrication of Microfluidic Valves Using a Hydrogel Molding Method

NASA Astrophysics Data System (ADS)

Sugiura, Yusuke; Hirama, Hirotada; Torii, Toru

2015-08-01

In this paper, a method for fabricating a microfluidic valve made of polydimethylsiloxane (PDMS) using a rapid prototyping method for microchannels through hydrogel cast molding is discussed. Currently, the valves in microchannels play an important role in various microfluidic devices. The technology to prototype microfluidic valves rapidly is actively being developed. For the rapid prototyping of PDMS microchannels, a method that uses a hydrogel as the casting mold has been recently developed. This technique can be used to prepare a three-dimensional structure through simple and uncomplicated methods. In this study, we were able to fabricate microfluidic valves easily using this rapid prototyping method that utilizes hydrogel cast molding. In addition, we confirmed that the valve displacement could be predicted within a range of constant pressures. Moreover, because microfluidic valves fabricated using this method can be directly observed from a cross-sectional direction, we anticipate that this technology will significantly contribute to clarifying fluid behavior and other phenomena in microchannels and microfluidic valves with complex structures.

Fabrication of Microfluidic Valves Using a Hydrogel Molding Method.

PubMed

Sugiura, Yusuke; Hirama, Hirotada; Torii, Toru

2015-08-24

In this paper, a method for fabricating a microfluidic valve made of polydimethylsiloxane (PDMS) using a rapid prototyping method for microchannels through hydrogel cast molding is discussed. Currently, the valves in microchannels play an important role in various microfluidic devices. The technology to prototype microfluidic valves rapidly is actively being developed. For the rapid prototyping of PDMS microchannels, a method that uses a hydrogel as the casting mold has been recently developed. This technique can be used to prepare a three-dimensional structure through simple and uncomplicated methods. In this study, we were able to fabricate microfluidic valves easily using this rapid prototyping method that utilizes hydrogel cast molding. In addition, we confirmed that the valve displacement could be predicted within a range of constant pressures. Moreover, because microfluidic valves fabricated using this method can be directly observed from a cross-sectional direction, we anticipate that this technology will significantly contribute to clarifying fluid behavior and other phenomena in microchannels and microfluidic valves with complex structures.

Fabrication of polymeric nano-batteries array using anodic aluminum oxide templates.

PubMed

Zhao, Qiang; Cui, Xiaoli; Chen, Ling; Liu, Ling; Sun, Zhenkun; Jiang, Zhiyu

2009-02-01

Rechargeable nano-batteries were fabricated in the array pores of anodic aluminum oxide (AAO) template, combining template method and electrochemical method. The battery consisted of electropolymerized PPy electrode, porous TiO2 separator, and chemically polymerized PAn electrode was fabricated in the array pores of two-step anodizing aluminum oxide (AAO) membrane, based on three-step assembling method. It performs typical electrochemical battery behavior with good charge-discharge ability, and presents a capacity of 25 nAs. AFM results show the hexagonal array of nano-batteries' top side. The nano-battery may be a promising device for the development of Micro-Electro-Mechanical Systems (MEMS), and Nano-Electro-Mechanical Systems (NEMS).

Nanofabrication

DOEpatents

Tuominen, Mark; Bal, Mustafa; Russell, Thomas P.; Ursache, Andrei

2007-03-13

Pathways to rapid and reliable fabrication of three-dimensional nanostructures are provided. Simple methods are described for the production of well-ordered, multilevel nanostructures. This is accomplished by patterning block copolymer templates with selective exposure to a radiation source. The resulting multi-scale lithographic template can be treated with post-fabrication steps to produce multilevel, three-dimensional, integrated nanoscale media, devices, and systems.

Design, fabrication, and operation of hybrid bionanodevices for biomedical applications

NASA Astrophysics Data System (ADS)

Tucker, Robert Matthew

Cells are the fundamental building blocks of life. Despite their simplicity, cells are extremely versatile, performing a variety of functions including detection, signaling, and repair. While current biomedical devices operate at the organ level, the next generation will operate at the cellular level, combining the nanoscale machinery of cells with the mechanical robustness of synthetic materials in the form of new hybrid devices. This thesis presents advances in four topics concerning the development of nanomedical devices: fabrication, stabilization, control, and operation. First, as feature sizes decrease from the milli- and microscale towards the nanoscale, new fabrication methods must be developed. A new rapid prototyping technique using confocal microscopy was used to produce freely-programmable high-resolution protein patterns of functional motor proteins on thermo-responsive polymer surfaces. Second, hybrid device operation should be temperature-independent, but most biological components have strong responses to temperature fluctuations. To counter operational fluctuations, the temperature-dependent enzymatic activity was characterized for two types of molecular motors with the goal of developing a bionanosystem which is stabilized against temperature fluctuations. Third, replacing electromechanical systems consisting of pumps and batteries with proteins that directly convert chemical potential into mechanical energy increases the efficiency and decreases the size of the bionanodevice, but requires new control methods. An enzymatic network was developed in which fuel was photolytically released to activate molecular shuttles, excess fuel was sequestered using an enzyme, and spatial and temporal control of the system was achieved. Finally, chemically powered bionanodevices will require high-precision nano- and microscale actuators. A two-part hybrid actuator was designed, which consists of a molecular motor-coated synthetic macroscale forcer and a microtubule-based stator. Methods to create and characterize the stator were developed, which can be used to optimize the force generation of the device.

Tetrakis(1-imidazolyl) borate (BIM4) based zwitterionic and related molecules used as electron injection layers

DOEpatents

Li, Huaping; Xu, Yunhua; Bazan, Guillermo C

2013-02-05

Tetrakis(1-imidazolyl)borate (BIm4) based zwitterionic and/or related molecules for the fabrication of PLEDs is provided. Device performances with these materials approaches that of devices with Ba/Al cathodes for which the cathode contact is ohmic. Methods of producing such materials, and electron injection layers and devices containing these materials are also provided.

Scalable electro-photonic integration concept based on polymer waveguides

NASA Astrophysics Data System (ADS)

Bosman, E.; Van Steenberge, G.; Boersma, A.; Wiegersma, S.; Harmsma, P.; Karppinen, M.; Korhonen, T.; Offrein, B. J.; Dangel, R.; Daly, A.; Ortsiefer, M.; Justice, J.; Corbett, B.; Dorrestein, S.; Duis, J.

2016-03-01

A novel method for fabricating a single mode optical interconnection platform is presented. The method comprises the miniaturized assembly of optoelectronic single dies, the scalable fabrication of polymer single mode waveguides and the coupling to glass fiber arrays providing the I/O's. The low cost approach for the polymer waveguide fabrication is based on the nano-imprinting of a spin-coated waveguide core layer. The assembly of VCSELs and photodiodes is performed before waveguide layers are applied. By embedding these components in deep reactive ion etched pockets in the silicon substrate, the planarity of the substrate for subsequent layer processing is guaranteed and the thermal path of chip-to-substrate is minimized. Optical coupling of the embedded devices to the nano-imprinted waveguides is performed by laser ablating 45 degree trenches which act as optical mirror for 90 degree deviation of the light from VCSEL to waveguide. Laser ablation is also implemented for removing parts of the polymer stack in order to mount a custom fabricated connector containing glass fiber arrays. A demonstration device was built to show the proof of principle of the novel fabrication, packaging and optical coupling principles as described above, combined with a set of sub-demonstrators showing the functionality of the different techniques separately. The paper represents a significant part of the electro-photonic integration accomplishments in the European 7th Framework project "Firefly" and not only discusses the development of the different assembly processes described above, but the efforts on the complete integration of all process approaches into the single device demonstrator.

Aperiodic Volume Optics

NASA Astrophysics Data System (ADS)

Gerke, Tim D.

Presented in this thesis is an investigation into aperiodic volume optical devices. The three main topics of research and discussion are the aperiodic volume optical devices that we call computer-generated volume holograms (CGVH), defects within periodic 3D photonic crystals, and non-periodic, but ordered 3D quasicrystals. The first of these devices, CGVHs, are designed and investigated numerically and experimentally. We study the performance of multi-layered amplitude computer-generated volume holograms in terms of efficiency and angular/frequency selectivity. Simulation results show that such aperiodic devices can increase diffraction efficiency relative to periodic amplitude volume holograms while maintaining angular and wavelength selectivity. CGVHs are also designed as voxelated volumes using a new projection optimization algorithm. They are investigated using a volumetric diffraction simulation and a standard 3D beam propagation technique as well as experimentally. Both simulation and experiment verify that the structures function according to their design. These represent the first diffractive structures that have the capacity for generating arbitrary transmission and reflection wave fronts and that provide the ability for multiplexing arbitrary functionality given different illumination conditions. Also investigated and discussed in this thesis are 3D photonic crystals and quasicrystals. We demonstrate that these devices can be fabricated using a femtosecond laser direct writing system that is particularly appropriate for fabrication of such arbitrary 3D structures. We also show that these devices can provide 3D partial bandgaps which could become complete bandgaps if fabricated using high index materials or by coating lower index materials with high index metals. Our fabrication method is particularly suited to the fabrication of engineered defects within the periodic or quasi-periodic systems. We demonstrate the potential for fabricating defects within periodic and quasi-periodic systems for the manipulation of light in the IR regime. The general thesis of this document is that aperiodic three-dimensional structures provide additional degrees of freedom that can be utilized to improve on the performance of periodic volume devices. The results we will discuss suggest that, under certain circumstances, a departure from the Bragg paradigm provides enhanced volume diffraction properties.

Facile and Scalable Fabrication of Highly Efficient Lead Iodide Perovskite Thin-Film Solar Cells in Air Using Gas Pump Method.

PubMed

Ding, Bin; Gao, Lili; Liang, Lusheng; Chu, Qianqian; Song, Xiaoxuan; Li, Yan; Yang, Guanjun; Fan, Bin; Wang, Mingkui; Li, Chengxin; Li, Changjiu

2016-08-10

Control of the perovskite film formation process to produce high-quality organic-inorganic metal halide perovskite thin films with uniform morphology, high surface coverage, and minimum pinholes is of great importance to highly efficient solar cells. Herein, we report on large-area light-absorbing perovskite films fabrication with a new facile and scalable gas pump method. By decreasing the total pressure in the evaporation environment, the gas pump method can significantly enhance the solvent evaporation rate by 8 times faster and thereby produce an extremely dense, uniform, and full-coverage perovskite thin film. The resulting planar perovskite solar cells can achieve an impressive power conversion efficiency up to 19.00% with an average efficiency of 17.38 ± 0.70% for 32 devices with an area of 5 × 2 mm, 13.91% for devices with a large area up to 1.13 cm(2). The perovskite films can be easily fabricated in air conditions with a relative humidity of 45-55%, which definitely has a promising prospect in industrial application of large-area perovskite solar panels.

Fabrication of robust hydrogel coatings on polydimethylsiloxane substrates using micropillar anchor structures with chemical surface modification.

PubMed

Zhang, Hongbin; Bian, Chao; Jackson, John K; Khademolhosseini, Farzad; Burt, Helen M; Chiao, Mu

2014-06-25

A durable hydrophilic and protein-resistant surface of polydimethylsiloxane (PDMS) based devices is desirable in many biomedical applications such as implantable and microfluidic devices. This paper describes a stable antifouling hydrogel coating on PDMS surfaces. The coating method combines chemical modification and surface microstructure fabrication of PDMS substrates. Three-(trimethoxysilyl)propyl methacrylates containing C═C groups were used to modify PDMS surfaces with micropillar array structures fabricated by a replica molding method. The micropillar structures increase the surface area of PDMS surfaces, which facilitates secure bonding with a hydrogel coating compared to flat PMDS surfaces. The adhesion properties of the hydrogel coating on PDMS substrates were characterized using bending, stretching and water immersion tests. Long-term hydrophilic stability (maintaining a contact angle of 55° for a month) and a low protein adsorption property (35 ng/cm(2) of adsorbed BSA-FITC) of the hydrogel coated PDMS were demonstrated. This coating method is suitable for PDMS modification with most crosslinkable polymers containing C═C groups, which can be useful for improving the anti-biofouling performance of PDMS-based biomedical microdevices.

Improved performance of mesostructured perovskite solar cells via an anti-solvent method

NASA Astrophysics Data System (ADS)

Hao, Jiabin; Hao, Huiying; Cheng, Feiyu; Li, Jianfeng; Zhang, Haiyu; Dong, Jingjing; Xing, Jie; Liu, Hao; Wu, Jian

2018-06-01

One-step solution process is a facile and widely used procedure to prepare organic-inorganic perovskite materials. However, the poor surface morphology of the films attributed to the uncontrollable nucleation and crystal growth in the process is unfavorable to solar cells. In this study, an anti-solvent treatment during the one-step solution process, in which ethyl acetate (EA) was dropped on the sample during spinning the precursor solution containing CH3NH3Cl, was adopted to fabricate perovskite materials and solar cells. It was found that the morphology of the perovskite film was significantly improved due to the rapid nucleation and slow crystal growth process. The modified process enabled us to fabricate the mesoporous solar cell with power conversion efficiency of 14%, showing an improvement of 40% over the efficiency of 9.7% of the device prepared by conventional one-step method. The controlling effect of annealing time on the morphology, crystal structure and transport properties of perovskite layer as well as the performance of device fabricated by the anti-solvent method were investigated and the possible mechanism was discussed.

Microfabrication of microchannels for fuel cell plates.

PubMed

Jang, Ho Su; Park, Dong Sam

2010-01-01

Portable electronic devices such as notebook computers, PDAs, cellular phones, etc., are being widely used, and they increasingly need cheap, efficient, and lightweight power sources. Fuel cells have been proposed as possible power sources to address issues that involve energy production and the environment. In particular, a small type of fuel-cell system is known to be suitable for portable electronic devices. The development of micro fuel cell systems can be achieved by the application of microchannel technology. In this study, the conventional method of chemical etching and the mechanical machining method of micro end milling were used for the microfabrication of microchannel for fuel cell separators. The two methods were compared in terms of their performance in the fabrication with regards to dimensional errors, flatness, straightness, and surface roughness. Following microchannel fabrication, the powder blasting technique is introduced to improve the coating performance of the catalyst on the surface of the microchannel. Experimental results show that end milling can remarkably increase the fabrication performance and that surface treatment by powder blasting can improve the performance of catalyst coating.

Microfabrication of Microchannels for Fuel Cell Plates

PubMed Central

Jang, Ho Su; Park, Dong Sam

2010-01-01

Portable electronic devices such as notebook computers, PDAs, cellular phones, etc., are being widely used, and they increasingly need cheap, efficient, and lightweight power sources. Fuel cells have been proposed as possible power sources to address issues that involve energy production and the environment. In particular, a small type of fuel-cell system is known to be suitable for portable electronic devices. The development of micro fuel cell systems can be achieved by the application of microchannel technology. In this study, the conventional method of chemical etching and the mechanical machining method of micro end milling were used for the microfabrication of microchannel for fuel cell separators. The two methods were compared in terms of their performance in the fabrication with regards to dimensional errors, flatness, straightness, and surface roughness. Following microchannel fabrication, the powder blasting technique is introduced to improve the coating performance of the catalyst on the surface of the microchannel. Experimental results show that end milling can remarkably increase the fabrication performance and that surface treatment by powder blasting can improve the performance of catalyst coating. PMID:22315533

Preparation of Janus Particles and Alternating Current Electrokinetic Measurements with a Rapidly Fabricated Indium Tin Oxide Electrode Array.

PubMed

Chen, Yu-Liang; Jiang, Hong-Ren

2017-06-23

This article provides a simple method to prepare partially or fully coated metallic particles and to perform the rapid fabrication of electrode arrays, which can facilitate electrical experiments in microfluidic devices. Janus particles are asymmetric particles that contain two different surface properties on their two sides. To prepare Janus particles, a monolayer of silica particles is prepared by a drying process. Gold (Au) is deposited on one side of each particle using a sputtering device. The fully coated metallic particles are completed after the second coating process. To analyze the electrical surface properties of Janus particles, alternating current (AC) electrokinetic measurements, such as dielectrophoresis (DEP) and electrorotation (EROT)- which require specifically designed electrode arrays in the experimental device- are performed. However, traditional methods to fabricate electrode arrays, such as the photolithographic technique, require a series of complicated procedures. Here, we introduce a flexible method to fabricate a designed electrode array. An indium tin oxide (ITO) glass is patterned by a fiber laser marking machine (1,064 nm, 20 W, 90 to 120 ns pulse-width, and 20 to 80 kHz pulse repetition frequency) to create a four-phase electrode array. To generate the four-phase electric field, the electrodes are connected to a 2-channel function generator and to two invertors. The phase shift between the adjacent electrodes is set at either 90° (for EROT) or 180° (for DEP). Representative results of AC electrokinetic measurements with a four-phase ITO electrode array are presented.

Luminous fabric devices for wearable low-level light therapy

PubMed Central

Shen, Jing; Chui, Chunghin; Tao, Xiaoming

2013-01-01

In this paper, a flexible luminous fabric device was developed and investigated for wearable three-dimensionally fitted low-level light therapy. The fabric device exhibited excellent optical and thermal properties. Its optical power density and operating temperature were stable during usage for 10 hours. In vitro experiments demonstrated a significant increase in collagen production in human fibroblast irradiated by the fabric device, compared with the fibroblast without light irradiation. A series of tests were conducted for the safety of the fabric for human skin contact according to ISO standard ISO 10993-1:2003. The results showed that there was no potential hazard when the luminous fabrics were in direct contact with human skin. PMID:24409391

Methods for forming particles from single source precursors

DOEpatents

Fox, Robert V [Idaho Falls, ID; Rodriguez, Rene G [Pocatello, ID; Pak, Joshua [Pocatello, ID

2011-08-23

Single source precursors are subjected to carbon dioxide to form particles of material. The carbon dioxide may be in a supercritical state. Single source precursors also may be subjected to supercritical fluids other than supercritical carbon dioxide to form particles of material. The methods may be used to form nanoparticles. In some embodiments, the methods are used to form chalcopyrite materials. Devices such as, for example, semiconductor devices may be fabricated that include such particles. Methods of forming semiconductor devices include subjecting single source precursors to carbon dioxide to form particles of semiconductor material, and establishing electrical contact between the particles and an electrode.

Surface-Embedded Stretchable Electrodes by Direct Printing and their Uses to Fabricate Ultrathin Vibration Sensors and Circuits for 3D Structures.

PubMed

Song, Jun Hyuk; Kim, Young-Tae; Cho, Sunghwan; Song, Woo-Jin; Moon, Sungmin; Park, Chan-Gyung; Park, Soojin; Myoung, Jae Min; Jeong, Unyong

2017-11-01

Printing is one of the easy and quick ways to make a stretchable wearable electronics. Conventional printing methods deposit conductive materials "on" or "inside" a rubber substrate. The conductors made by such printing methods cannot be used as device electrodes because of the large surface topology, poor stretchability, or weak adhesion between the substrate and the conducting material. Here, a method is presented by which conductive materials are printed in the way of being surface-embedded in the rubber substrate; hence, the conductors can be widely used as device electrodes and circuits. The printing process involves a direct printing of a metal precursor solution in a block-copolymer rubber substrate and chemical reduction of the precursor into metal nanoparticles. The electrical conductivity and sensitivity to the mechanical deformation can be controlled by adjusting the number of printing operations. The fabrication of highly sensitive vibration sensors is thus presented, which can detect weak pulses and sound waves. In addition, this work takes advantage of the viscoelasticity of the composite conductor to fabricate highly conductive stretchable circuits for complicated 3D structures. The printed electrodes are also used to fabricate a stretchable electrochemiluminescence display. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phase Conjugated and Transparent Wavelength Conversions of Nyquist 16-QAM Signals Employing a Single-Layer Graphene Coated Fiber Device

PubMed Central

Hu, Xiao; Zeng, Mengqi; Long, Yun; Liu, Jun; Zhu, Yixiao; Zou, Kaiheng; Zhang, Fan; Fu, Lei; Wang, Jian

2016-01-01

We fabricate a nonlinear optical device based on a fiber pigtail cross-section coated with a single-layer graphene grown by chemical vapor deposition (CVD) method. Using the fabricated graphene-assisted nonlinear optical device and employing Nyquist 16-ary quadrature amplitude modulation (16-QAM) signal, we experimentally demonstrate phase conjugated wavelength conversion by degenerate four-wave mixing (FWM) and transparent wavelength conversion by non-degenerate FWM in graphene. We study the conversion efficiency as functions of the pump power and pump wavelength and evaluate the bit-error rate (BER) performance. We also compare the time-varying symbol sequence for graphene-assisted phase conjugated and transparent wavelength conversions of Nyquist 16-QAM signal. PMID:26932470

Resistive switching based on filaments in metal/PMMA/metal thin film devices

NASA Astrophysics Data System (ADS)

Wolf, Christoph; Nau, Sebastian; Sax, Stefan; Busby, Yan; Pireaux, Jean-Jacques; List-Kratochvil, Emil J. W.

2015-12-01

The working mechanism of unipolar organic resistive switching thin-film devices is investigated. On the basis of a metal/poly(methyl methacrylate)/metal model system, direct spectroscopic evidence for filament formation is obtained by three-dimensional (3D) imaging with time-of-flight secondary ion mass spectrometry. By means of alternative fabrication methods the claimed influence of metal implantation in the organic layer during fabrication is ruled out. Further, the stability of the resistive switches under oxygen and humidity is investigated leading to a deeper understanding of the processes governing the formation and rupture of filaments.

Micro- and nanofabrication methods in nanotechnological medical and pharmaceutical devices

PubMed Central

Betancourt, Tania; Brannon-Peppas, Lisa

2006-01-01

Micro- and nanofabrication techniques have revolutionized the pharmaceutical and medical fields as they offer the possibility for highly reproducible mass-fabrication of systems with complex geometries and functionalities, including novel drug delivery systems and bionsensors. The principal micro- and nanofabrication techniques are described, including photolithography, soft lithography, film deposition, etching, bonding, molecular self assembly, electrically induced nanopatterning, rapid prototyping, and electron, X-ray, colloidal monolayer, and focused ion beam lithography. Application of these techniques for the fabrication of drug delivery and biosensing systems including injectable, implantable, transdermal, and mucoadhesive devices is described. PMID:17722281

Fabrication of Glass Microchannel via Glass Imprinting using a Vitreous Carbon Stamp for Flow Focusing Droplet Generator

PubMed Central

Refatul Haq, Muhammad; Kim, Youngkyu; Kim, Jun; Oh, Pyoung-hwa; Ju, Jonghyun; Kim, Seok-Min; Lim, Jiseok

2017-01-01

This study reports a cost-effective method of replicating glass microfluidic chips using a vitreous carbon (VC) stamp. A glass replica with the required microfluidic microstructures was synthesized without etching. The replication method uses a VC stamp fabricated by combining thermal replication using a furan-based, thermally-curable polymer with carbonization. To test the feasibility of this method, a flow focusing droplet generator with flow-focusing and channel widths of 50 µm and 100 µm, respectively, was successfully fabricated in a soda-lime glass substrate. Deviation between the geometries of the initial shape and the vitreous carbon mold occurred because of shrinkage during the carbonization process, however this effect could be predicted and compensated for. Finally, the monodispersity of the droplets generated by the fabricated microfluidic device was evaluated. PMID:29286341

Three-dimensional illusion thermal device for location camouflage.

PubMed

Wang, Jing; Bi, Yanqiang; Hou, Quanwen

2017-08-08

Thermal metamaterials, proposed in recent years, provide a new method to manipulate the energy flux in heat transfer, and result in many novel thermal devices. In this paper, an illusion thermal device for location camouflage in 3-dimensional heat conduction regime is proposed based on the transformation thermodynamics. The heat source covered by the device produces a fake signal outside the device, which makes the source look like appearing at another position away from its real position. The parameters required by the device are deduced and the method is validated by simulations. The possible scheme to obtain the thermal conductivities required in the device by composing natural materials is supplied, and the influence of some problems in practical fabrication process of the device on the effect of the camouflage is also discussed.

Fabrication of Three-dimensional Paper-based Microfluidic Devices for Immunoassays.

PubMed

Fernandes, Syrena C; Wilson, Daniel J; Mace, Charles R

2017-03-09

Paper wicks fluids autonomously due to capillary action. By patterning paper with hydrophobic barriers, the transport of fluids can be controlled and directed within a layer of paper. Moreover, stacking multiple layers of patterned paper creates sophisticated three-dimensional microfluidic networks that can support the development of analytical and bioanalytical assays. Paper-based microfluidic devices are inexpensive, portable, easy to use, and require no external equipment to operate. As a result, they hold great promise as a platform for point-of-care diagnostics. In order to properly evaluate the utility and analytical performance of paper-based devices, suitable methods must be developed to ensure their manufacture is reproducible and at a scale that is appropriate for laboratory settings. In this manuscript, a method to fabricate a general device architecture that can be used for paper-based immunoassays is described. We use a form of additive manufacturing (multi-layer lamination) to prepare devices that comprise multiple layers of patterned paper and patterned adhesive. In addition to demonstrating the proper use of these three-dimensional paper-based microfluidic devices with an immunoassay for human chorionic gonadotropin (hCG), errors in the manufacturing process that may result in device failures are discussed. We expect this approach to manufacturing paper-based devices will find broad utility in the development of analytical applications designed specifically for limited-resource settings.

Graphene interfaced perovskite solar cells: Role of graphene flake size

NASA Astrophysics Data System (ADS)

Sakorikar, Tushar; Kavitha, M. K.; Tong, Shi Wun; Vayalamkuzhi, Pramitha; Loh, Kian Ping; Jaiswal, Manu

2018-04-01

Graphene interfaced inverted planar heterojunction perovskite solar cells are fabricated by facile solution method and studied its potential as hole conducting layer. Reduced graphene oxide (rGO) with small and large flake size and Polyethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS) are utilized as hole conducting layers in different devices. For the solar cell employing PEDOT:PSS as hole conducting layer, 3.8 % photoconversion efficiency is achieved. In case of solar cells fabricated with rGO as hole conducting layer, the efficiency of the device is strongly dependent on flake size. With all other fabrication conditions kept constant, the efficiency of graphene-interfaced solar cell improves by a factor of 6, by changing the flake size of graphene oxide. We attribute this effect to uniform coverage of graphene layer and improved electrical percolation network.

A comprehensive review of select smart polymeric and gel actuators for soft mechatronics and robotics applications: fundamentals, freeform fabrication, and motion control

NASA Astrophysics Data System (ADS)

Carrico, James D.; Tyler, Tom; Leang, Kam K.

2017-10-01

Smart polymeric and gel actuators change shape or size in response to stimuli like electricity, heat, or light. These smart polymeric- and gel-based actuators are compliant and well suited for development of soft mechatronic and robotic devices. This paper provides a thorough review of select smart polymeric and gel actuator materials where an automated and freeform fabrication process, like 3D printing, is exploited to create custom shaped monolithic devices. In particular, the advantages and limitations, examples of applications, manufacturing and fabrication techniques, and methods for actuator control are discussed. Finally, a rigorous comparison and analysis of some of the advantages and limitations, as well as manufacturing processes, for these materials, are presented.

Water-based and biocompatible 2D crystal inks for all-inkjet-printed heterostructures

NASA Astrophysics Data System (ADS)

McManus, Daryl; Vranic, Sandra; Withers, Freddie; Sanchez-Romaguera, Veronica; Macucci, Massimo; Yang, Huafeng; Sorrentino, Roberto; Parvez, Khaled; Son, Seok-Kyun; Iannaccone, Giuseppe; Kostarelos, Kostas; Fiori, Gianluca; Casiraghi, Cinzia

2017-05-01

Exploiting the properties of two-dimensional crystals requires a mass production method able to produce heterostructures of arbitrary complexity on any substrate. Solution processing of graphene allows simple and low-cost techniques such as inkjet printing to be used for device fabrication. However, the available printable formulations are still far from ideal as they are either based on toxic solvents, have low concentration, or require time-consuming and expensive processing. In addition, none is suitable for thin-film heterostructure fabrication due to the re-mixing of different two-dimensional crystals leading to uncontrolled interfaces and poor device performance. Here, we show a general approach to achieve inkjet-printable, water-based, two-dimensional crystal formulations, which also provide optimal film formation for multi-stack fabrication. We show examples of all-inkjet-printed heterostructures, such as large-area arrays of photosensors on plastic and paper and programmable logic memory devices. Finally, in vitro dose-escalation cytotoxicity assays confirm the biocompatibility of the inks, extending their possible use to biomedical applications.

Fabrication of p-type CuO thin films using chemical bath deposition technique and their solar cell applications with Si nanowires

NASA Astrophysics Data System (ADS)

Akgul, Funda Aksoy; Akgul, Guvenc

2017-02-01

Recently, CuO has attracted much interest owing to its suitable material properties, inexpensive fabrication cost and potential applications for optoelectronic devices. In this study, CuO thin films were deposited on glass substrates using chemical bath deposition technique and post-deposition annealing effect on the properties of the prepared samples were investigated. p-n heterojunction solar cells were then constructed by coating of p-type CuO films onto the vertically well-aligned n-type Si nanowires synthesized through MACE method. Photovoltaic performance of the fabricated devices were determined with current-voltage (I-V) measurements under AM 1.5 G illumination. The optimal short-circuit current density, open-circuit voltage, fill factor and power conversion efficiency were found to be 3.2 mA/cm-2, 337 mV, 37.9 and 0.45%, respectively. The observed performance clearly indicates that the investigated device structure could be a promising candidate for high-performance low-cost new-generation photovoltaic diodes.

A Combined Fabrication and Instrumentation Platform for Sample Preparation.

PubMed

Guckenberger, David J; Thomas, Peter C; Rothbauer, Jacob; LaVanway, Alex J; Anderson, Meghan; Gilson, Dan; Fawcett, Kevin; Berto, Tristan; Barrett, Kevin; Beebe, David J; Berry, Scott M

2014-06-01

While potentially powerful, access to molecular diagnostics is substantially limited in the developing world. Here we present an approach to reduced cost molecular diagnostic instrumentation that has the potential to empower developing world communities by reducing costs through streamlining the sample preparation process. In addition, this instrument is capable of producing its own consumable devices on demand, reducing reliance on assay suppliers. Furthermore, this instrument is designed with an "open" architecture, allowing users to visually observe the assay process and make modifications as necessary (as opposed to traditional "black box" systems). This open environment enables integration of microfluidic fabrication and viral RNA purification onto an easy-to-use modular system via the use of interchangeable trays. Here we employ this system to develop a protocol to fabricate microfluidic devices and then use these devices to isolate viral RNA from serum for the measurement of human immunodeficiency virus (HIV) viral load. Results obtained from this method show significantly reduced error compared with similar nonautomated sample preparation processes. © 2014 Society for Laboratory Automation and Screening.

Evolving MEMS Resonator Designs for Fabrication

NASA Technical Reports Server (NTRS)

Hornby, Gregory S.; Kraus, William F.; Lohn, Jason D.

2008-01-01

Because of their small size and high reliability, microelectromechanical (MEMS) devices have the potential to revolution many areas of engineering. As with conventionally-sized engineering design, there is likely to be a demand for the automated design of MEMS devices. This paper describes our current status as we progress toward our ultimate goal of using an evolutionary algorithm and a generative representation to produce designs of a MEMS device and successfully demonstrate its transfer to an actual chip. To produce designs that are likely to transfer to reality, we present two ways to modify evaluation of designs. The first is to add location noise, differences between the actual dimensions of the design and the design blueprint, which is a technique we have used for our work in evolving antennas and robots. The second method is to add prestress to model the warping that occurs during the extreme heat of fabrication. In future we expect to fabricate and test some MEMS resonators that are evolved in this way.

A self-assembled microbonded germanium/silicon heterojunction photodiode for 25 Gb/s high-speed optical interconnects

PubMed Central

Tseng, Chih-Kuo; Chen, Wei-Ting; Chen, Ku-Hung; Liu, Han-Din; Kang, Yimin; Na, Neil; Lee, Ming-Chang M.

2013-01-01

A novel technique using surface tension to locally bond germanium (Ge) on silicon (Si) is presented for fabricating high performance Ge/Si photodiodes. Surface tension is a cohesive force among liquid molecules that tends to bring contiguous objects in contact to maintain a minimum surface energy. We take advantage of this phenomenon to fabricate a heterojunction optoelectronic device where the lattice constants of joined semiconductors are different. A high-speed Ge/Si heterojunction waveguide photodiode is presented by microbonding a beam-shaped Ge, first grown by rapid-melt-growth (RMG) method, on top of a Si waveguide via surface tension. Excellent device performances such as an operating bandwidth of 17 GHz and a responsivity of 0.66 and 0.70 A/W at the reverse bias of −4 and −6 V, respectively, are demonstrated. This technique can be simply implemented via modern complementary metal-oxide-semiconductor (CMOS) fabrication technologies for integrating Ge on Si devices. PMID:24232956

Development of paper-based microfluidic analytical device for iron assay using photomask printed with 3D printer for fabrication of hydrophilic and hydrophobic zones on paper by photolithography.

PubMed

Asano, Hitoshi; Shiraishi, Yukihide

2015-07-09

This paper describes a paper-based microfluidic analytical device for iron assay using a photomask printed with a 3D printer for fabrication of hydrophilic and hydrophobic zones on the paper by photolithography. Several designed photomasks for patterning paper-based microfluidic analytical devices can be printed with a 3D printer easily, rapidly and inexpensively. A chromatography paper was impregnated with the octadecyltrichlorosilane n-hexane solution and hydrophobized. After the hydrophobic zone of the paper was exposed to the UV light through the photomask, the hydrophilic zone was generated. The smallest functional hydrophilic channel and hydrophobic barrier were ca. 500 μm and ca. 100 μm in width, respectively. The fabrication method has high stability, resolution and precision for hydrophilic channel and hydrophobic barrier. This test paper was applied to the analysis of iron in water samples using a colorimetry with phenanthroline. Copyright © 2015 Elsevier B.V. All rights reserved.

Fused Deposition Modeling 3D Printing for (Bio)analytical Device Fabrication: Procedures, Materials, and Applications

PubMed Central

2017-01-01

In this work, the use of fused deposition modeling (FDM) in a (bio)analytical/lab-on-a-chip research laboratory is described. First, the specifications of this 3D printing method that are important for the fabrication of (micro)devices were characterized for a benchtop FDM 3D printer. These include resolution, surface roughness, leakage, transparency, material deformation, and the possibilities for integration of other materials. Next, the autofluorescence, solvent compatibility, and biocompatibility of 12 representative FDM materials were tested and evaluated. Finally, we demonstrate the feasibility of FDM in a number of important applications. In particular, we consider the fabrication of fluidic channels, masters for polymer replication, and tools for the production of paper microfluidic devices. This work thus provides a guideline for (i) the use of FDM technology by addressing its possibilities and current limitations, (ii) material selection for FDM, based on solvent compatibility and biocompatibility, and (iii) application of FDM technology to (bio)analytical research by demonstrating a broad range of illustrative examples. PMID:28628294

Aluminium alloyed iron-silicide/silicon solar cells: A simple approach for low cost environmental-friendly photovoltaic technology

PubMed Central

Kumar Dalapati, Goutam; Masudy-Panah, Saeid; Kumar, Avishek; Cheh Tan, Cheng; Ru Tan, Hui; Chi, Dongzhi

2015-01-01

This work demonstrates the fabrication of silicide/silicon based solar cell towards the development of low cost and environmental friendly photovoltaic technology. A heterostructure solar cells using metallic alpha phase (α-phase) aluminum alloyed iron silicide (FeSi(Al)) on n-type silicon is fabricated with an efficiency of 0.8%. The fabricated device has an open circuit voltage and fill-factor of 240 mV and 60%, respectively. Performance of the device was improved by about 7 fold to 5.1% through the interface engineering. The α-phase FeSi(Al)/silicon solar cell devices have promising photovoltaic characteristic with an open circuit voltage, short-circuit current and a fill factor (FF) of 425 mV, 18.5 mA/cm2, and 64%, respectively. The significant improvement of α-phase FeSi(Al)/n-Si solar cells is due to the formation p+−n homojunction through the formation of re-grown crystalline silicon layer (~5–10 nm) at the silicide/silicon interface. Thickness of the regrown silicon layer is crucial for the silicide/silicon based photovoltaic devices. Performance of the α-FeSi(Al)/n-Si solar cells significantly depends on the thickness of α-FeSi(Al) layer and process temperature during the device fabrication. This study will open up new opportunities for the Si based photovoltaic technology using a simple, sustainable, and los cost method. PMID:26632759

Solid electrolyte-electrode system for an electrochemical cell

DOEpatents

Tuller, Harry L.; Kramer, Steve A.; Spears, Marlene A.

1995-01-01

An electrochemical device including a solid electrolyte and solid electrode composed of materials having different chemical compositions and characterized by different electrical properties but having the same crystalline phase is provided. A method for fabricating an electrochemical device having a solid electrode and solid electrolyte characterized by the same crystalline phase is also provided.

Characterization of Bonding Between Poly(dimethylsiloxane) and Cyclic Olefin Coplymer Using Corona Discharge Induced Grafting Polymerization

PubMed Central

Liu, Ke; Gu, Pan; Hamaker, Kiri; Fan, Z. Hugh

2011-01-01

Thermoplastics have been increasingly used for fabricating microfluidic devices because of their low cost, mechanical/biocompatible attributes, and well-established manufacturing processes. However, there is sometimes a need to integrate such a device with components made from other materials such as polydimethylsiloxane (PDMS). Bonding thermoplastics with PDMS to produce hybrid devices is not straightforward. We have reported our method to modify the surface property of a cyclic olefin copolymer (COC) substrate by using corona discharge and grafting polymerization of 3-(trimethoxysilyl)propyl methacrylate; the modified surface enabled strong bonding of COC with PDMS. In this paper, we report our studies on the surface modification mechanism using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and contact angle measurement. Using this bonding method, we fabricated a three-layer (COC/PDMS/COC) hybrid device consisting of elastomer-based valve arrays. The microvalve operation was confirmed through the displacement of a dye solution in a fluidic channel when the elastomer membrane was pneumatically actuated. Valve-enabled microfluidic handling was demonstrated. PMID:21962541

Fabrication of two-layer poly(dimethyl siloxane) devices for hydrodynamic cell trapping and exocytosis measurement with integrated indium tin oxide microelectrodes arrays

PubMed Central

Gao, Changlu; Sun, Xiuhua; Gillis, Kevin D.

2016-01-01

The design, fabrication and test of a microfluidic cell trapping device to measure single cell exocytosis were reported. Research on the patterning of double layer template based on repetitive standard photolithography of AZ photoresist was investigated. The replicated poly(dimethyl siloxane) devices with 2.5 μm deep channels were proved to be efficient for stopping cells. Quantal exocytosis measurement can be achieved by targeting single or small clumps of chromaffin cells on top of the 10 μm ×10 μm indium tin oxide microelectrodes arrays with the developed microdevice. And about 72% of the trapping sites can be occupied by cells with hydrodynamic trapping method and the recorded amperometric signals are comparable to the results with traditional carbon fiber microelectrodes. The method of manufacturing the microdevices is simple, low-cost and easy to perform. The manufactured device offers a platform for the high throughput detection of quantal catecholamine exocytosis from chromaffin cells with sufficient sensitivity and broad application. PMID:23329291

III-V nanowire synthesis by use of electrodeposited gold particles.

PubMed

Jafari Jam, Reza; Heurlin, Magnus; Jain, Vishal; Kvennefors, Anders; Graczyk, Mariusz; Maximov, Ivan; Borgström, Magnus T; Pettersson, Håkan; Samuelson, Lars

2015-01-14

Semiconductor nanowires are great candidates for building novel electronic devices. Considering the cost of fabricating such devices, substrate reuse and gold consumption are the main concerns. Here we report on implementation of high throughput gold electrodeposition for selective deposition of metal seed particles in arrays defined by lithography for nanowire synthesis. By use of this method, a reduction in gold consumption by a factor of at least 300 was achieved, as compared to conventional thermal evaporation for the same pattern. Because this method also facilitates substrate reuse, a significantly reduced cost of the final device is expected. We investigate the morphology, crystallography, and optical properties of InP and GaAs nanowires grown from electrodeposited gold seed particles and compare them with the properties of nanowires grown from seed particles defined by thermal evaporation of gold. We find that nanowire synthesis, as well as the material properties of the grown nanowires are comparable and quite independent of the gold deposition technique. On the basis of these results, electrodeposition is proposed as a key technology for large-scale fabrication of nanowire-based devices.

Nanoscale Reactive Ion Etching of Silicon Nitride Thin Films for Embedded Nanomagnetic Device Fabrication

NASA Astrophysics Data System (ADS)

Hibbard-Lubow, David Luke

The demands of digital memory have increased exponentially in recent history, requiring faster, smaller and more accurate storage methods. Two promising solutions to this ever-present problem are Bit Patterned Media (BPM) and Spin-Transfer Torque Magnetic Random Access Memory (STT-MRAM). Producing these technologies requires difficult and expensive fabrication techniques. Thus, the production processes must be optimized to allow these storage methods to compete commercially while continuing to increase their information storage density and reliability. I developed a process for the production of nanomagnetic devices (which can take the form of several types of digital memory) embedded in thin silicon nitride films. My focus was on optimizing the reactive ion etching recipe required to embed the device in the film. Ultimately, I found that recipe 37 (Power: 250W, CF4 nominal/actual flow rate: 25/25.4 sccm, O2 nominal/actual flow rate: 3.1/5.2 sccm, which gave a maximum pressure around 400 mTorr) gave the most repeatable and anisotropic results. I successfully used processes described in this thesis to make embedded nanomagnets, which could be used as bit patterned media. Another promising application of this work is to make embedded magnetic tunneling junctions, which are the storage medium used in MRAM. Doing so will require still some tweaks to the fabrication methods. Techniques for making these changes and their potential effects are discussed.

Oriented thin films of mixture of a low-bandgap polymer and a fullerene derivative prepared by friction-transfer method

NASA Astrophysics Data System (ADS)

Tanigaki, Nobutaka; Mizokuro, Toshiko; Miyadera, Tetsuhiko; Shibata, Yousei; Koganezawa, Tomoyuki

2018-02-01

We have been studying oriented thin films of polymers fabricated by the friction-transfer method, which allows the alignment of a variety of conjugated polymers into highly oriented films. In this study, we prepared oriented blend films of a mixture of a low-bandgap polymer, poly{4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b‧]dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophene-4,6-diyl} (PTB7), and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM), which is a promising combination for application in organic solar cells. We obtained oriented blend films of PTB7 and PC71BM by the friction-transfer method from a solid block. Polarized UV-visible spectra show that the PTB7 chains were aligned parallel to the friction direction in the blend films. Grazing-incidence X-ray diffraction (GIXD) studies with synchrotron radiation suggested that the preferred orientation of PTB7 crystallites was face-on in the blend films. The GIXD results also showed the high uniaxial orientation of PTB7 chains in blend films. Photovoltaic devices were fabricated using the friction-transferred blend films of the PTB7 and PC71BM. These bulk heterojunction devices showed better performance than planar heterojunction devices fabricated using pure friction-transferred PTB7 films.

Fabrication and characterization of the organic rectifying junctions by electrolysis

NASA Astrophysics Data System (ADS)

Karimov, Khasan; Ahmad, Zubair; Ali, Rashid; Noor, Adnan; Akmal, M.; Najeeb, M. A.; Shakoor, R. A.

2017-08-01

Unlike the conventional solution processable deposition techniques, in this study, we propose a novel and economical method for the fabrication of organic rectifying junctions. The solutions of the orange dye, copper phthalocyanine and NaCl were deposited on the surface-type interdigitated silver electrodes using electrolysis technique. Using the current-voltage (I-V) characteristics, the presence of rectifying behavior in the samples has been confirmed. This phenomenon, in principle, can be used for fabrication of the diodes, transistors and memory devices.

NbN superconducting nanonetwork fabricated using porous silicon templates and high-resolution electron beam lithography

NASA Astrophysics Data System (ADS)

Salvato, M.; Baghdadi, R.; Cirillo, C.; Prischepa, S. L.; Dolgiy, A. L.; Bondarenko, V. P.; Lombardi, F.; Attanasio, C.

2017-11-01

Superconducting NbN nanonetworks with a very small number of interconnected nanowires, with diameter of the order of 4 nm, are fabricated combining a bottom-up (use of porous silicon nanotemplates) with a top-down technique (high-resolution electron beam lithography). The method is easy to control and allows the fabrication of devices, on a robust support, with electrical properties close to a one-dimensional superconductor that can be used fruitfully for novel applications.

Fabrication of all-carbon nanotube electronic devices on flexible substrates through CVD and transfer methods.

PubMed

Zou, Yuan; Li, Qunqing; Liu, Junku; Jin, Yuanhao; Qian, Qingkai; Jiang, Kaili; Fan, Shoushan

2013-11-13

SWNT thin films with different nanotube densities are fabricated by CVD while controlling the concentration of catalyst and growth time. Three layers of SWNT films are transferred to flexible substrates serving as electrodes and channel materials, respectively. All-carbon nanotube TFTs with an on/off ratio as high as 10(5) are obtained. Inverters are fabricated on top of the flexible substrates with symmetric input/output behavior. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High Efficiency Coupling of Optical Fibres with SU8 Micro-droplet Using Laser Welding Process

NASA Astrophysics Data System (ADS)

Yardi, Seema; Gupta, Ankur; Sundriyal, Poonam; Bhatt, Geeta; Kant, Rishi; Boolchandani, D.; Bhattacharya, Shantanu

2016-09-01

Apart from micro- structure fabrication, ablation, lithography etc., lasers find a lot of utility in various areas like precision joining, device fabrication, local heat delivery for surface texturing and local change of microstructure fabrication of standalone optical micro-devices (like microspheres, micro-prisms, micro-scale ring resonators, optical switches etc). There is a wide utility of such systems in chemical/ biochemical diagnostics and also communications where the standalone optical devices exist at a commercial scale but chip based devices with printed optics are necessary due to coupling issues between printed structures and external optics. This paper demonstrates a novel fabrication strategy used to join standalone optical fibres to microchip based printed optics using a simple SU8 drop. The fabrication process is deployed for fiber to fiber optical coupling and coupling between fiber and printed SU-8 waveguides. A CO2 laser is used to locally heat the coupling made up of SU8 material. Optimization of various dimensional parameters using design of experiments (DOE) on the bonded assembly has been performed as a function of laser power, speed, cycle control, spot size so on so forth. Exclusive optical [RF] modelling has been performed to estimate the transmissibility of the optical fibers bonded to each other on a surface with SU8. Our studies indicate the formation of a Whispering gallery mode (WGM) across the micro-droplet leading to high transmissibility of the signal. Through this work we have thus been able to develop a method of fabrication for optical coupling of standalone fibers or coupling of on-chip optics with off-chip illumination/detection.

Cermet insert high voltage holdoff improvement for ceramic/metal vacuum devices

DOEpatents

Ierna, W.F.

1986-03-11

An improved metal-to-ceramic seal is provided wherein the ceramic body of the seal contains an integral region of cermet material in electrical contact with the metallic member, e.g., an electrode, of the seal. The seal is useful in high voltage vacuum devices, e.g., vacuum switches, and increases the high-voltage holdoff capabilities of such devices. A method of fabricating such seals is also provided.

Cermet insert high voltage holdoff for ceramic/metal vacuum devices

DOEpatents

Ierna, William F.

1987-01-01

An improved metal-to-ceramic seal is provided wherein the ceramic body of the seal contains an integral region of cermet material in electrical contact with the metallic member, e.g., an electrode, of the seal. The seal is useful in high voltage vacuum devices, e.g., vacuum switches, and increases the high-voltage holdoff capabilities of such devices. A method of fabricating such seals is also provided.

A Strategy to Design High-Density Nanoscale Devices utilizing Vapor Deposition of Metal Halide Perovskite Materials.

PubMed

Hwang, Bohee; Lee, Jang-Sik

2017-08-01

The demand for high memory density has increased due to increasing needs of information storage, such as big data processing and the Internet of Things. Organic-inorganic perovskite materials that show nonvolatile resistive switching memory properties have potential applications as the resistive switching layer for next-generation memory devices, but, for practical applications, these materials should be utilized in high-density data-storage devices. Here, nanoscale memory devices are fabricated by sequential vapor deposition of organolead halide perovskite (OHP) CH 3 NH 3 PbI 3 layers on wafers perforated with 250 nm via-holes. These devices have bipolar resistive switching properties, and show low-voltage operation, fast switching speed (200 ns), good endurance, and data-retention time >10 5 s. Moreover, the use of sequential vapor deposition is extended to deposit CH 3 NH 3 PbI 3 as the memory element in a cross-point array structure. This method to fabricate high-density memory devices could be used for memory cells that occupy large areas, and to overcome the scaling limit of existing methods; it also presents a way to use OHPs to increase memory storage capacity. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improving Mechanical Properties of Molded Silicone Rubber for Soft Robotics Through Fabric Compositing.

PubMed

Wang, Yue; Gregory, Cherry; Minor, Mark A

2018-06-01

Molded silicone rubbers are common in manufacturing of soft robotic parts, but they are often prone to tears, punctures, and tensile failures when strained. In this article, we present a fabric compositing method for improving the mechanical properties of soft robotic parts by creating a fabric/rubber composite that increases the strength and durability of the molded rubber. Comprehensive ASTM material tests evaluating the strength, tear resistance, and puncture resistance are conducted on multiple composites embedded with different fabrics, including polyester, nylon, silk, cotton, rayon, and several blended fabrics. Results show that strong fabrics increase the strength and durability of the composite, valuable in pneumatic soft robotic applications, while elastic fabrics maintain elasticity and enhance tear strength, suitable for robotic skins or soft strain sensors. Two case studies then validate the proposed benefits of the fabric compositing for soft robotic pressure vessel applications and soft strain sensor applications. Evaluations of the fabric/rubber composite samples and devices indicate that such methods are effective for improving mechanical properties of soft robotic parts, resulting in parts that can have customized stiffness, strength, and vastly improved durability.

Amorphous Silicon Based Neutron Detector

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

Xu, Liwei

2004-12-12

Various large-scale neutron sources already build or to be constructed, are important for materials research and life science research. For all these neutron sources, neutron detectors are very important aspect. However, there is a lack of a high-performance and low-cost neutron beam monitor that provides time and temporal resolution. The objective of this SBIR Phase I research, collaboratively performed by Midwest Optoelectronics, LLC (MWOE), the University of Toledo (UT) and Oak Ridge National Laboratory (ORNL), is to demonstrate the feasibility for amorphous silicon based neutron beam monitors that are pixilated, reliable, durable, fully packaged, and fabricated with high yield usingmore » low-cost method. During the Phase I effort, work as been focused in the following areas: 1) Deposition of high quality, low-defect-density, low-stress a-Si films using very high frequency plasma enhanced chemical vapor deposition (VHF PECVD) at high deposition rate and with low device shunting; 2) Fabrication of Si/SiO2/metal/p/i/n/metal/n/i/p/metal/SiO2/ device for the detection of alpha particles which are daughter particles of neutrons through appropriate nuclear reactions; and 3) Testing of various devices fabricated for alpha and neutron detection; As the main results: · High quality, low-defect-density, low-stress a-Si films have been successfully deposited using VHF PECVD on various low-cost substrates; · Various single-junction and double junction detector devices have been fabricated; · The detector devices fabricated have been systematically tested and analyzed. · Some of the fabricated devices are found to successfully detect alpha particles. Further research is required to bring this Phase I work beyond the feasibility demonstration toward the final prototype devices. The success of this project will lead to a high-performance, low-cost, X-Y pixilated neutron beam monitor that could be used in all of the neutron facilities worldwide. In addition, the technologies developed here could be used to develop X-ray and neutron monitors that could be used in the future for security checks at the airports and other critical facilities. The project would lead to devices that could significantly enhance the performance of multi-billion dollar neutron source facilities in the US and bring our nation to the forefront of neutron beam sciences and technologies which have enormous impact to materials, life science and military research and applications.« less

Bench-Top Fabrication of an All-PDMS Microfluidic Electrochemical Cell Sensor Integrating Micro/Nanostructured Electrodes.

PubMed

Saem, Sokunthearath; Zhu, Yujie; Luu, Helen; Moran-Mirabal, Jose

2017-03-31

In recent years, efforts in the development of lab-on-a-chip (LoC) devices for point-of-care (PoC) applications have increased to bring affordable, portable, and sensitive diagnostics to the patients' bedside. To reach this goal, research has shifted from using traditional microfabrication methods to more versatile, rapid, and low-cost options. This work focuses on the benchtop fabrication of a highly sensitive, fully transparent, and flexible poly (dimethylsiloxane) (PDMS) microfluidic (μF) electrochemical cell sensor. The μF device encapsulates 3D structured gold and platinum electrodes, fabricated using a shape-memory polymer shrinking method, which are used to set up an on-chip electrochemical cell. The PDMS to PDMS-structured electrode bonding protocol to fabricate the μF chip was optimized and found to have sufficient bond strength to withstand up to 100 mL/min flow rates. The sensing capabilities of the on-chip electrochemical cell were demonstrated by using cyclic voltammetry to monitor the adhesion of murine 3T3 fibroblasts in the presence of a redox reporter. The charge transfer across the working electrode was reduced upon cell adhesion, which was used as the detection mechanism, and allowed the detection of as few as 24 cells. The effective utilization of simple and low cost bench-top fabrication methods could accelerate the prototyping and development of LoC technologies and bring PoC diagnostics and personalized medicine to the patients' bedside.

Bench-Top Fabrication of an All-PDMS Microfluidic Electrochemical Cell Sensor Integrating Micro/Nanostructured Electrodes

PubMed Central

Saem, Sokunthearath; Zhu, Yujie; Luu, Helen; Moran-Mirabal, Jose

2017-01-01

In recent years, efforts in the development of lab-on-a-chip (LoC) devices for point-of-care (PoC) applications have increased to bring affordable, portable, and sensitive diagnostics to the patients’ bedside. To reach this goal, research has shifted from using traditional microfabrication methods to more versatile, rapid, and low-cost options. This work focuses on the benchtop fabrication of a highly sensitive, fully transparent, and flexible poly (dimethylsiloxane) (PDMS) microfluidic (μF) electrochemical cell sensor. The μF device encapsulates 3D structured gold and platinum electrodes, fabricated using a shape-memory polymer shrinking method, which are used to set up an on-chip electrochemical cell. The PDMS to PDMS-structured electrode bonding protocol to fabricate the μF chip was optimized and found to have sufficient bond strength to withstand up to 100 mL/min flow rates. The sensing capabilities of the on-chip electrochemical cell were demonstrated by using cyclic voltammetry to monitor the adhesion of murine 3T3 fibroblasts in the presence of a redox reporter. The charge transfer across the working electrode was reduced upon cell adhesion, which was used as the detection mechanism, and allowed the detection of as few as 24 cells. The effective utilization of simple and low cost bench-top fabrication methods could accelerate the prototyping and development of LoC technologies and bring PoC diagnostics and personalized medicine to the patients’ bedside. PMID:28362329

High performance printed oxide field-effect transistors processed using photonic curing.

PubMed

Garlapati, Suresh Kumar; Marques, Gabriel Cadilha; Gebauer, Julia Susanne; Dehm, Simone; Bruns, Michael; Winterer, Markus; Tahoori, Mehdi Baradaran; Aghassi-Hagmann, Jasmin; Hahn, Horst; Dasgupta, Subho

2018-06-08

Oxide semiconductors are highly promising candidates for the most awaited, next-generation electronics, namely, printed electronics. As a fabrication route for the solution-processed/printed oxide semiconductors, photonic curing is becoming increasingly popular, as compared to the conventional thermal curing method; the former offers numerous advantages over the latter, such as low process temperatures and short exposure time and thereby, high throughput compatibility. Here, using dissimilar photonic curing concepts (UV-visible light and UV-laser), we demonstrate facile fabrication of high performance In 2 O 3 field-effect transistors (FETs). Beside the processing related issues (temperature, time etc.), the other known limitation of oxide electronics is the lack of high performance p-type semiconductors, which can be bypassed using unipolar logics from high mobility n-type semiconductors alone. Interestingly, here we have found that our chosen distinct photonic curing methods can offer a large variation in threshold voltage, when they are fabricated from the same precursor ink. Consequently, both depletion and enhancement-mode devices have been achieved which can be used as the pull-up and pull-down transistors in unipolar inverters. The present device fabrication recipe demonstrates fast processing of low operation voltage, high performance FETs with large threshold voltage tunability.

Overcoming Short-Circuit in Lead-Free CH3NH3SnI3 Perovskite Solar Cells via Kinetically Controlled Gas-Solid Reaction Film Fabrication Process.

PubMed

Yokoyama, Takamichi; Cao, Duyen H; Stoumpos, Constantinos C; Song, Tze-Bin; Sato, Yoshiharu; Aramaki, Shinji; Kanatzidis, Mercouri G

2016-03-03

The development of Sn-based perovskite solar cells has been challenging because devices often show short-circuit behavior due to poor morphologies and undesired electrical properties of the thin films. A low-temperature vapor-assisted solution process (LT-VASP) has been employed as a novel kinetically controlled gas-solid reaction film fabrication method to prepare lead-free CH3NH3SnI3 thin films. We show that the solid SnI2 substrate temperature is the key parameter in achieving perovskite films with high surface coverage and excellent uniformity. The resulting high-quality CH3NH3SnI3 films allow the successful fabrication of solar cells with drastically improved reproducibility, reaching an efficiency of 1.86%. Furthermore, our Kelvin probe studies show the VASP films have a doping level lower than that of films prepared from the conventional one-step method, effectively lowering the film conductivity. Above all, with (LT)-VASP, the short-circuit behavior often obtained from the conventional one-step-fabricated Sn-based perovskite devices has been overcome. This study facilitates the path to more successful Sn-perovskite photovoltaic research.

High performance printed oxide field-effect transistors processed using photonic curing

NASA Astrophysics Data System (ADS)

Garlapati, Suresh Kumar; Cadilha Marques, Gabriel; Gebauer, Julia Susanne; Dehm, Simone; Bruns, Michael; Winterer, Markus; Baradaran Tahoori, Mehdi; Aghassi-Hagmann, Jasmin; Hahn, Horst; Dasgupta, Subho

2018-06-01

Oxide semiconductors are highly promising candidates for the most awaited, next-generation electronics, namely, printed electronics. As a fabrication route for the solution-processed/printed oxide semiconductors, photonic curing is becoming increasingly popular, as compared to the conventional thermal curing method; the former offers numerous advantages over the latter, such as low process temperatures and short exposure time and thereby, high throughput compatibility. Here, using dissimilar photonic curing concepts (UV–visible light and UV-laser), we demonstrate facile fabrication of high performance In2O3 field-effect transistors (FETs). Beside the processing related issues (temperature, time etc.), the other known limitation of oxide electronics is the lack of high performance p-type semiconductors, which can be bypassed using unipolar logics from high mobility n-type semiconductors alone. Interestingly, here we have found that our chosen distinct photonic curing methods can offer a large variation in threshold voltage, when they are fabricated from the same precursor ink. Consequently, both depletion and enhancement-mode devices have been achieved which can be used as the pull-up and pull-down transistors in unipolar inverters. The present device fabrication recipe demonstrates fast processing of low operation voltage, high performance FETs with large threshold voltage tunability.

Methods for growth of relatively large step-free SiC crystal surfaces

NASA Technical Reports Server (NTRS)

Neudeck, Philip G. (Inventor); Powell, J. Anthony (Inventor)

2002-01-01

A method for growing arrays of large-area device-size films of step-free (i.e., atomically flat) SiC surfaces for semiconductor electronic device applications is disclosed. This method utilizes a lateral growth process that better overcomes the effect of extended defects in the seed crystal substrate that limited the obtainable step-free area achievable by prior art processes. The step-free SiC surface is particularly suited for the heteroepitaxial growth of 3C (cubic) SiC, AlN, and GaN films used for the fabrication of both surface-sensitive devices (i.e., surface channel field effect transistors such as HEMT's and MOSFET's) as well as high-electric field devices (pn diodes and other solid-state power switching devices) that are sensitive to extended crystal defects.

Developing a protocol for creating microfluidic devices with a 3D printer, PDMS, and glass

NASA Astrophysics Data System (ADS)

Collette, Robyn; Novak, Eric; Shirk, Kathryn

2015-03-01

Microfluidics research requires the design and fabrication of devices that have the ability to manipulate small volumes of fluid, typically ranging from microliters to picoliters. These devices are used for a wide range of applications including the assembly of materials and testing of biological samples. Many methods have been previously developed to create microfluidic devices, including traditional nanolithography techniques. However, these traditional techniques are cost-prohibitive for many small-scale laboratories. This research explores a relatively low-cost technique using a 3D printed master, which is used as a template for the fabrication of polydimethylsiloxane (PDMS) microfluidic devices. The masters are designed using computer aided design (CAD) software and can be printed and modified relatively quickly. We have developed a protocol for creating simple microfluidic devices using a 3D printer and PDMS adhered to glass. This relatively simple and lower-cost technique can now be scaled to more complicated device designs and applications. Funding provided by the Undergraduate Research Grant Program at Shippensburg University and the Student/Faculty Research Engagement Grants from the College of Arts and Sciences at Shippensburg University.

Flow-through polymerase chain reaction inside a seamless 3D helical microreactor fabricated utilizing a silicone tube and a paraffin mold.

PubMed

Wu, Wenming; Trinh, Kieu The Loan; Lee, Nae Yoon

2015-03-07

We introduce a new strategy for fabricating a seamless three-dimensional (3D) helical microreactor utilizing a silicone tube and a paraffin mold. With this method, various shapes and sizes of 3D helical microreactors were fabricated, and a complicated and laborious photolithographic process, or 3D printing, was eliminated. With dramatically enhanced portability at a significantly reduced fabrication cost, such a device can be considered to be the simplest microreactor, developed to date, for performing the flow-through polymerase chain reaction (PCR).

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

NONE

Work under DOE Grant No. DE-FG47-93R701314, to investigate a Novel Process for Fabricating MOSFET Devices, has progressed to a point where feasibility of producing MOSFETS using Chromium Disilicide Schottky barrier junctions at Source and Drain has been shown. Devices fabricated, however, show inconsistent operating characteristics from device to device, and further work is required to overcome the defects. Some fabrication procedures have produced a relatively high, (e.g., ninety-five (95%) percent), yield of devices on a substrate which show at least some transistor action, while others have resulted in very low yield, (e.g., five (5%) percent). Consistency of results from devicemore » to device is less than desired. However, considering that the University of Nebraska at Lincoln (UNL) Electrical Engineering Fabrication Lab is not what industry can provide, it is reasonable to project that essentially one-hundred (99.99+%) percent yield should be achievable in an industrial setting because of the simplicity in the fabrication procedure.« less

Device and method for luminescence enhancement by resonant energy transfer from an absorptive thin film

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

Akselrod, Gleb M.; Bawendi, Moungi G.; Bulovic, Vladimir

Disclosed are a device and a method for the design and fabrication of the device for enhancing the brightness of luminescent molecules, nanostructures, and thin films. The device includes a mirror, a dielectric medium or spacer, an absorptive layer, and a luminescent layer. The absorptive layer is a continuous thin film of a strongly absorbing organic or inorganic material. The luminescent layer may be a continuous luminescent thin film or an arrangement of isolated luminescent species, e.g., organic or metal-organic dye molecules, semiconductor quantum dots, or other semiconductor nanostructures, supported on top of the absorptive layer.

Thiol-modified MoS2 nanosheets as a functional layer for electrical bistable devices

NASA Astrophysics Data System (ADS)

Li, Guan; Tan, Fenxue; Lv, Bokun; Wu, Mengying; Wang, Ruiqi; Lu, Yue; Li, Xu; Li, Zhiqiang; Teng, Feng

2018-01-01

Molybdenum disulfide nanosheets have been synthesized by one-pot method using 1-ODT as sulfur source and surfactant. The structure, morphology and optical properties of samples were investigated by XRD, FTIR, Abs spectrum and TEM patterns. The XRD pattern indicated that the as-obtained MoS2 belong to hexagonal system. The as-obtained MoS2 nanosheets blending with PVK could be used to fabricate an electrically bistable devices through a simple spin-coating method and the device exhibited an obvious electrical bistability properties. The charge transport mechanism of the device was discussed based on the filamentary switching models.

Method for extracting relevant electrical parameters from graphene field-effect transistors using a physical model

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

Boscá, A., E-mail: alberto.bosca@upm.es; Dpto. de Ingeniería Electrónica, E.T.S.I. de Telecomunicación, Universidad Politécnica de Madrid, Madrid 28040; Pedrós, J.

2015-01-28

Due to its intrinsic high mobility, graphene has proved to be a suitable material for high-speed electronics, where graphene field-effect transistor (GFET) has shown excellent properties. In this work, we present a method for extracting relevant electrical parameters from GFET devices using a simple electrical characterization and a model fitting. With experimental data from the device output characteristics, the method allows to calculate parameters such as the mobility, the contact resistance, and the fixed charge. Differentiated electron and hole mobilities and direct connection with intrinsic material properties are some of the key aspects of this method. Moreover, the method outputmore » values can be correlated with several issues during key fabrication steps such as the graphene growth and transfer, the lithographic steps, or the metalization processes, providing a flexible tool for quality control in GFET fabrication, as well as a valuable feedback for improving the material-growth process.« less

Light emitting ceramic device and method for fabricating the same

DOEpatents

Valentine, Paul; Edwards, Doreen D.; Walker Jr., William John; Slack, Lyle H.; Brown, Wayne Douglas; Osborne, Cathy; Norton, Michael; Begley, Richard

2004-11-30

A light-emitting ceramic based panel, hereafter termed "electroceramescent" panel, and alternative methods of fabrication for the same are claimed. The electroceramescent panel is formed on a substrate providing mechanical support as well as serving as the base electrode for the device. One or more semiconductive ceramic layers directly overlay the substrate, and electrical conductivity and ionic diffusion are controlled. Light emitting regions overlay the semiconductive ceramic layers, and said regions consist sequentially of a layer of a ceramic insulation layer and an electroluminescent layer, comprised of doped phosphors or the equivalent. One or more conductive top electrode layers having optically transmissive areas overlay the light emitting regions, and a multi-layered top barrier cover comprising one or more optically transmissive non-combustible insulation layers overlay said top electrode regions.

On-chip supercapacitors with ultrahigh volumetric performance based on electrochemically co-deposited CuO/polypyrrole nanosheet arrays

NASA Astrophysics Data System (ADS)

Qian, Tao; Zhou, Jinqiu; Xu, Na; Yang, Tingzhou; Shen, Xiaowei; Liu, Xuejun; Wu, Shishan; Yan, Chenglin

2015-10-01

We introduce a new method for fabricating unique on-chip supercapacitors based on CuO/polypyrrole core/shell nanosheet arrays by means of direct electrochemical co-deposition on interdigital-like electrodes. The prepared all-solid-state device demonstrates exceptionally high specific capacitance of 1275.5 F cm-3 (˜40 times larger than that of CuO-only supercapacitors) and high-energy-density of 28.35 mWh cm-3, which are both significantly greater than other solid-state supercapacitors. More importantly, the device maintains approximately 100% capacity retention at 2.5 A cm-3 after 3000 cycles. The in situ co-deposition of CuO/polypyrrole nanosheets on interdigital substrate enables effective charge transport, electrode fabrication integrity, and device integration. Because of their high energy, power density, and stable cycling stability, these newly developed on-chip supercapacitors permit fast, reliable applications in portable and miniaturized electronic devices.

Method of making an integral window hermetic fiber optic component

DOEpatents

Dalton, R.D.; Kramer, D.P.; Massey, R.T.; Waker, D.A.

1996-11-12

In the fabrication of igniters, actuators, detonators, and other pyrotechnic devices to be activated by a laser beam, an integral optical glass window is formed by placing a preform in the structural member of the device and then melting the glass and sealing it in place by heating at a temperature between the ceramming temperature of the glass and the melting point of the metal, followed by rapid furnace cooling to avoid devitrification. No other sealing material is needed to achieve hermeticity. A preferred embodiment of this type of device is fabricated by allowing the molten glass to flow further and form a plano-convex lens integral with and at the bottom of the window. The lens functions to decrease the beam divergence caused by refraction of the laser light passing through the window when the device is fired by means of a laser beam. 9 figs.

Method of making an integral window hermetic fiber optic component

DOEpatents

Dalton, Rick D.; Kramer, Daniel P.; Massey, Richard T.; Waker, Damon A.

1996-11-12

In the fabrication of igniters, actuators, detonators, and other pyrotechnic devices to be activated by a laser beam, an integral optical glass window is formed by placing a preform in the structural member of the device and then melting the glass and sealing it in place by heating at a temperature between the ceramming temperature of the glass and the melting point of the metal, followed by rapid furnace cooling to avoid devitrification. No other sealing material is needed to achieve hermeticity. A preferred embodiment of this type of device is fabricated by allowing the molten glass to flow further and form a plano-convex lens integral with and at the bottom of the window. The lens functions to decrease the beam divergence caused by refraction of the laser light passing through the window when the device is fired by means of a laser beam.

On-chip supercapacitors with ultrahigh volumetric performance based on electrochemically co-deposited CuO/polypyrrole nanosheet arrays.

PubMed

Qian, Tao; Zhou, Jinqiu; Xu, Na; Yang, Tingzhou; Shen, Xiaowei; Liu, Xuejun; Wu, Shishan; Yan, Chenglin

2015-10-23

We introduce a new method for fabricating unique on-chip supercapacitors based on CuO/polypyrrole core/shell nanosheet arrays by means of direct electrochemical co-deposition on interdigital-like electrodes. The prepared all-solid-state device demonstrates exceptionally high specific capacitance of 1275.5 F cm(-3) (∼40 times larger than that of CuO-only supercapacitors) and high-energy-density of 28.35 mWh cm(-3), which are both significantly greater than other solid-state supercapacitors. More importantly, the device maintains approximately 100% capacity retention at 2.5 A cm(-3) after 3000 cycles. The in situ co-deposition of CuO/polypyrrole nanosheets on interdigital substrate enables effective charge transport, electrode fabrication integrity, and device integration. Because of their high energy, power density, and stable cycling stability, these newly developed on-chip supercapacitors permit fast, reliable applications in portable and miniaturized electronic devices.

Robust and stretchable indium gallium zinc oxide-based electronic textiles formed by cilia-assisted transfer printing

PubMed Central

Yoon, Jongwon; Jeong, Yunkyung; Kim, Heeje; Yoo, Seonggwang; Jung, Hoon Sun; Kim, Yonghun; Hwang, Youngkyu; Hyun, Yujun; Hong, Woong-Ki; Lee, Byoung Hun; Choa, Sung-Hoon; Ko, Heung Cho

2016-01-01

Electronic textile (e-textile) allows for high-end wearable electronic devices that provide easy access for carrying, handling and using. However, the related technology does not seem to be mature because the woven fabric hampers not only the device fabrication process directly on the complex surface but also the transfer printing of ultrathin planar electronic devices. Here we report an indirect method that enables conformal wrapping of surface with arbitrary yet complex shapes. Artificial cilia are introduced in the periphery of electronic devices as adhesive elements. The cilia also play an important role in confining a small amount of glue and damping mechanical stress to maintain robust electronic performance under mechanical deformation. The example of electronic applications depicts the feasibility of cilia for ‘stick-&-play' systems, which provide electronic functions by transfer printing on unconventional complex surfaces. PMID:27248982

Single-Step Reagentless Laser Scribing Fabrication of Electrochemical Paper-Based Analytical Devices.

PubMed

de Araujo, William R; Frasson, Carolina M R; Ameku, Wilson A; Silva, José R; Angnes, Lúcio; Paixão, Thiago R L C

2017-11-20

A single-step laser scribing process is used to pattern nanostructured electrodes on paper-based devices. The facile and low-cost technique eliminates the need for chemical reagents or controlled conditions. This process involves the use of a CO 2 laser to pyrolyze the surface of the paperboard, producing a conductive porous non-graphitizing carbon material composed of graphene sheets and composites with aluminosilicate nanoparticles. The new electrode material was extensively characterized, and it exhibits high conductivity and an enhanced active/geometric area ratio; it is thus well-suited for electrochemical purposes. As a proof-of-concept, the devices were successfully employed for different analytical applications in the clinical, pharmaceutical, food, and forensic fields. The scalable and green fabrication method associated with the features of the new material is highly promising for the development of portable electrochemical devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electromyographic evaluation in children orthodontically treated for skeletal Class II malocclusion: Comparison of two treatment techniques.

PubMed

Ortu, Eleonora; Pietropaoli, Davide; Adib, Fray; Masci, Chiara; Giannoni, Mario; Monaco, Annalisa

2017-11-16

Objective To compare the clinical efficacy of two techniques for fabricating a Bimler device by assessing the patient's surface electromyography (sEMG) activity at rest before treatment and six months after treatment. Methods Twenty-four patients undergoing orthodontic treatment were enrolled in the study; 12 formed the test group and wore a Bimler device fabricated with a Myoprint impression using neuromuscular orthodontic technique and 12 formed the control group and were treated by traditional orthodontic technique with a wax bite in protrusion. The "rest" sEMG of each patient was recorded prior to treatment and six months after treatment. Results The neuromuscular-designed Bimler device was more comfortable and provided better treatment results than the traditional Bimler device. Conclusion This study suggests that the patient group subjected to neuromuscular orthodontic treatment had a treatment outcome with more relaxed masticatory muscles and better function versus the traditional orthodontic treatment.

Micro Electromechanical Systems (MEMS) Based Microfluidic Devices for Biomedical Applications

PubMed Central

Ashraf, Muhammad Waseem; Tayyaba, Shahzadi; Afzulpurkar, Nitin

2011-01-01

Micro Electromechanical Systems (MEMS) based microfluidic devices have gained popularity in biomedicine field over the last few years. In this paper, a comprehensive overview of microfluidic devices such as micropumps and microneedles has been presented for biomedical applications. The aim of this paper is to present the major features and issues related to micropumps and microneedles, e.g., working principles, actuation methods, fabrication techniques, construction, performance parameters, failure analysis, testing, safety issues, applications, commercialization issues and future prospects. Based on the actuation mechanisms, the micropumps are classified into two main types, i.e., mechanical and non-mechanical micropumps. Microneedles can be categorized according to their structure, fabrication process, material, overall shape, tip shape, size, array density and application. The presented literature review on micropumps and microneedles will provide comprehensive information for researchers working on design and development of microfluidic devices for biomedical applications. PMID:21747700

Optoelectronic semiconductor device and method of fabrication

DOEpatents

Cui, Yi; Zhu, Jia; Hsu, Ching-Mei; Fan, Shanhui; Yu, Zongfu

2014-11-25

An optoelectronic device comprising an optically active layer that includes a plurality of domes is presented. The plurality of domes is arrayed in two dimensions having a periodicity in each dimension that is less than or comparable with the shortest wavelength in a spectral range of interest. By virtue of the plurality of domes, the optoelectronic device achieves high performance. A solar cell having high energy-conversion efficiency, improved absorption over the spectral range of interest, and an improved acceptance angle is presented as an exemplary device.

Spin Dependent Transport Properties of Metallic and Semiconducting Nanostructures

NASA Astrophysics Data System (ADS)

Sapkota, Keshab R.

Present computing and communication devices rely on two different classes of technologies; information processing devices are based on electrical charge transport in semiconducting materials while information storage devices are based on orientation of electron spins in magnetic materials. A realization of a hybrid-type device that is based on charge as well as spin properties of electrons would perform both of these actions thereby enhancing computation power to many folds and reducing power consumptions. This dissertation focuses on the fabrication of such spin-devices based on metallic and semiconducting nanostructures which can utilize spin as well as charge properties of electrons. A simplified design of the spin-device consists of a spin injector, a semiconducting or metallic channel, and a spin detector. The channel is the carrier of the spin signal from the injector to the detector and therefore plays a crucial role in the manipulation of spin properties in the device. In this work, nanostructures like nanowires and nanostripes are used to function the channel in the spin-device. Methods like electrospinning, hydrothermal, and wet chemical were used to synthesize nanowires while physical vapor deposition followed by heat treatment in controlled environment was used to synthesis nanostripes. Spin-devices fabrication of the synthesized nanostructures were carried out by electron beam lithography process. The details of synthesis of nanostructures, device fabrication procedures and measurement techniques will be discussed in the thesis. We have successfully fabricated the spin-devices of tellurium nanowire, indium nanostripe, and indium oxide nanostripe and studied their spin transport properties for the first time. These spin-devices show large spin relaxation length compared to normal metals like copper and offer potentials for the future technologies. Further, Heusler alloys nanowires like nanowires of Co 2FeAl were synthesized and studied for electrical transport properties since such systems are halfmetallic in nature and promise the possibilities of spin injection and detection. The study was extended to dilute magnetic semiconducting nanowire system of Cd1-xMnxTe which possess both magnetic and semiconducting properties. In summary, the studies made in this thesis will offer a new understanding of spin transport behavior for future technology.

3D printing of nano- and micro-structures

NASA Astrophysics Data System (ADS)

Ramasamy, Mouli; Varadan, Vijay K.

2016-04-01

Additive manufacturing or 3D printing techniques are being vigorously investigated as a replacement to the traditional and conventional methods in fabrication to bring forth cost and time effective approaches. Introduction of 3D printing has led to printing micro and nanoscale structures including tissues and organelles, bioelectric sensors and devices, artificial bones and transplants, microfluidic devices, batteries and various other biomaterials. Various microfabrication processes have been developed to fabricate micro components and assemblies at lab scale. 3D Fabrication processes that can accommodate the functional and geometrical requirements to realize complicated structures are becoming feasible through advances in additive manufacturing. This advancement could lead to simpler development mechanisms of novel components and devices exhibiting complex features. For instance, development of microstructure electrodes that can penetrate the epidermis of the skin to collect the bio potential signal may prove very effective than the electrodes that measure signal from the skin's surface. The micro and nanostructures will have to possess extraordinary material and mechanical properties for its dexterity in the applications. A substantial amount of research being pursued on stretchable and flexible devices based on PDMA, textiles, and organic electronics. Despite the numerous advantages these substrates and techniques could solely offer, 3D printing enables a multi-dimensional approach towards finer and complex applications. This review emphasizes the use of 3D printing to fabricate micro and nanostructures for that can be applied for human healthcare.

[Fabrications of a poly (methyl methacrylate) (PMMA) microfluidic chip-based DNA analysis device].

PubMed

Du, Xiao-Guang

2009-12-01

A DNA analysis device based on poly(methyl methacrylate) (PMMA) microfluidic chips was developed. A PMMA chip with cross microchannels was fabricated by a simple hot embossing. Microchannels were modified with a static adsorptive coating method using 2% hydroxyethyl cellulose. A high-voltage power unit, variable in the range 0-1 800 V, was used for on-chip DNA sample injection and gel electrophoretic separation. High speed, high resolution DNA analysis was obtained with the home-built PMMA chip in a sieving matrix containing 2% hydroxyethyl cellulose with a blue intercalating dye, TO-PRO-3 (TP3), by using diode laser induced fluorescence detection based on optical fibers with a 670 nm long-pass filter. The DNA analysis device was applied for the separation of phiX-174/HaeIII DNA digest sample with 11 fragments ranging from 72 to 1 353 bp. A separation efficiency of 1.14 x 10(6) plates/m was obtained for the 603 bp fragments, while the R of 271/281 bp fragments was 1.2. The device was characterized by simple design, low cost for fabrication and operation, reusable PMMA chips, and good reproducibility. A portable microfluidic device for DNA analysis can be developed for clinical diagnosis and disease screening.

RFID and Memory Devices Fabricated Integrally on Substrates

NASA Technical Reports Server (NTRS)

Schramm, Harry F.

2004-01-01

Electronic identification devices containing radio-frequency identification (RFID) circuits and antennas would be fabricated integrally with the objects to be identified, according to a proposal. That is to say, the objects to be identified would serve as substrates for the deposition and patterning of the materials of the devices used to identify them, and each identification device would be bonded to the identified object at the molecular level. Vacuum arc vapor deposition (VAVD) is the NASA derived process for depositing layers of material on the substrate. This proposal stands in contrast to the current practice of fabricating RFID and/or memory devices as wafer-based, self-contained integrated-circuit chips that are subsequently embedded in or attached to plastic cards to make smart account-information cards and identification badges. If one relies on such a chip to store data on the history of an object to be tracked and the chip falls off or out of the object, then one loses both the historical data and the means to track the object and verify its identity electronically. Also, in contrast is the manufacturing philosophy in use today to make many memory devices. Today s methods involve many subtractive processes such as etching. This proposal only uses additive methods, building RFID and memory devices from the substrate up in thin layers. VAVD is capable of spraying silicon, copper, and other materials commonly used in electronic devices. The VAVD process sprays most metals and some ceramics. The material being sprayed has a very strong bond with the substrate, whether that substrate is metal, ceramic, or even wood, rock, glass, PVC, or paper. An object to be tagged with an identification device according to the proposal must be compatible with a vacuum deposition process. Temperature is seldom an issue as the substrate rarely reaches 150 F (66 C) during the deposition process. A portion of the surface of the object would be designated as a substrate for the deposition of the device. By use of a vacuum arc vapor deposition apparatus, a thin electrically insulating film would first be deposited on the substrate. Subsequent layers of materials would then be deposited and patterned by use of known integrated-circuit fabrication techniques. The total thickness of the deposited layers could be much less than the 100- m thickness of the thinnest state-of-the-art self-contained microchips. Such a thin deposit could be readily concealed by simply painting over it. Both large vacuum chambers for production runs and portable hand-held devices for in situ applications are available.

Development of thermoelectric fibers for miniature thermoelectric devices

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

Ren, Fei; Menchhofer, Paul A.; Kiggans, Jr., James O.

Miniature thermoelectric (TE) devices may be used in a variety of applications such as power sources of small sensors, temperature regulation of precision electronics, etc. Reducing the size of TE elements may also enable design of novel devices with unique form factor and higher device efficiency. Current industrial practice of fabricating TE devices usually involves mechanical removal processes that not only lead to material loss but also limit the geometry of the TE elements. In this project, we explored a powder-processing method for the fabrication of TE fibers with large length-to-area ratio, which could be potentially used for miniature TEmore » devices. Powders were milled from Bi2Te3-based bulk materials and then mixed with a thermoplastic resin dissolved in an organic solvent. Through an extrusion process, flexible, continuous fibers with sub-millimeter diameters were formed. The polymer phase was then removed by sintering. Sintered fibers exhibited similar Seebeck coefficients to the bulk materials. Moreover, their electrical resistivity was much higher, which might be related to the residual porosity and grain boundary contamination. Prototype miniature uni-couples fabricated from these fibers showed a linear I-V behavior and could generate millivolt voltages and output power in the nano-watt range. Further development of these TE fibers requires improvement in their electrical conductivities, which needs a better understanding of the causes that lead to the low conductivity in the sintered fibers.« less

All-inkjet-printed flexible ZnO micro photodetector for a wearable UV monitoring device.

PubMed

Tran, Van-Thai; Wei, Yuefan; Yang, Hongyi; Zhan, Zhaoyao; Du, Hejun

2017-03-03

Fabrication of small-sized patterns of inorganic semiconductor onto flexible substrates is a major concern when manufacturing wearable devices for measuring either biometric or environmental parameters. In this study, micro-sized flexible ZnO UV photodetectors have been thoroughly prepared by a facile inkjet printing technology and followed with heat treatments. A simple ink recipe of zinc acetate precursor solution was investigated. It is found that the substrate temperature during zinc precursor ink depositing has significant effects on ZnO pattern shape, film morphology, and crystallization. The device fabricated from the additive manufacturing approach has good bendability, Ohmic contact, short response time as low as 0.3 s, and high on/off ratio of 3525. We observed the sensor's dependence of response/decay time by the illuminating UV light intensity. The whole process is based on additive manufacturing which has many benefits such as rapid prototyping, saving material, being environmentally friendly, and being capable of creating high-resolution patterns. In addition, this method can be applied to flexible substrates, which makes the device more applicable for applications requiring flexibility such as wearable devices. The proposed all-inkjet-printing approach for a micro-sized ZnO UV photodetector would significantly simplify the fabrication process of micro-sized inorganic semiconductor-based devices. A potential application is real-time monitoring of UV light exposure to warn users about unsafe direct sunlight to implement suitable avoidance solutions.

Development of thermoelectric fibers for miniature thermoelectric devices

DOE PAGES

Ren, Fei; Menchhofer, Paul A.; Kiggans, Jr., James O.; ...

2016-09-23

Miniature thermoelectric (TE) devices may be used in a variety of applications such as power sources of small sensors, temperature regulation of precision electronics, etc. Reducing the size of TE elements may also enable design of novel devices with unique form factor and higher device efficiency. Current industrial practice of fabricating TE devices usually involves mechanical removal processes that not only lead to material loss but also limit the geometry of the TE elements. In this project, we explored a powder-processing method for the fabrication of TE fibers with large length-to-area ratio, which could be potentially used for miniature TEmore » devices. Powders were milled from Bi2Te3-based bulk materials and then mixed with a thermoplastic resin dissolved in an organic solvent. Through an extrusion process, flexible, continuous fibers with sub-millimeter diameters were formed. The polymer phase was then removed by sintering. Sintered fibers exhibited similar Seebeck coefficients to the bulk materials. Moreover, their electrical resistivity was much higher, which might be related to the residual porosity and grain boundary contamination. Prototype miniature uni-couples fabricated from these fibers showed a linear I-V behavior and could generate millivolt voltages and output power in the nano-watt range. Further development of these TE fibers requires improvement in their electrical conductivities, which needs a better understanding of the causes that lead to the low conductivity in the sintered fibers.« less

Two- and three-dimensional folding of thin film single-crystalline silicon for photovoltaic power applications

PubMed Central

Guo, Xiaoying; Li, Huan; Yeop Ahn, Bok; Duoss, Eric B.; Hsia, K. Jimmy; Lewis, Jennifer A.; Nuzzo, Ralph G.

2009-01-01

Fabrication of 3D electronic structures in the micrometer-to-millimeter range is extremely challenging due to the inherently 2D nature of most conventional wafer-based fabrication methods. Self-assembly, and the related method of self-folding of planar patterned membranes, provide a promising means to solve this problem. Here, we investigate self-assembly processes driven by wetting interactions to shape the contour of a functional, nonplanar photovoltaic (PV) device. A mechanics model based on the theory of thin plates is developed to identify the critical conditions for self-folding of different 2D geometrical shapes. This strategy is demonstrated for specifically designed millimeter-scale silicon objects, which are self-assembled into spherical, and other 3D shapes and integrated into fully functional light-trapping PV devices. The resulting 3D devices offer a promising way to efficiently harvest solar energy in thin cells using concentrator microarrays that function without active light tracking systems. PMID:19934059

Atomic switch networks—nanoarchitectonic design of a complex system for natural computing

NASA Astrophysics Data System (ADS)

Demis, E. C.; Aguilera, R.; Sillin, H. O.; Scharnhorst, K.; Sandouk, E. J.; Aono, M.; Stieg, A. Z.; Gimzewski, J. K.

2015-05-01

Self-organized complex systems are ubiquitous in nature, and the structural complexity of these natural systems can be used as a model to design new classes of functional nanotechnology based on highly interconnected networks of interacting units. Conventional fabrication methods for electronic computing devices are subject to known scaling limits, confining the diversity of possible architectures. This work explores methods of fabricating a self-organized complex device known as an atomic switch network and discusses its potential utility in computing. Through a merger of top-down and bottom-up techniques guided by mathematical and nanoarchitectonic design principles, we have produced functional devices comprising nanoscale elements whose intrinsic nonlinear dynamics and memorization capabilities produce robust patterns of distributed activity and a capacity for nonlinear transformation of input signals when configured in the appropriate network architecture. Their operational characteristics represent a unique potential for hardware implementation of natural computation, specifically in the area of reservoir computing—a burgeoning field that investigates the computational aptitude of complex biologically inspired systems.

Atomic switch networks-nanoarchitectonic design of a complex system for natural computing.

PubMed

Demis, E C; Aguilera, R; Sillin, H O; Scharnhorst, K; Sandouk, E J; Aono, M; Stieg, A Z; Gimzewski, J K

2015-05-22

Self-organized complex systems are ubiquitous in nature, and the structural complexity of these natural systems can be used as a model to design new classes of functional nanotechnology based on highly interconnected networks of interacting units. Conventional fabrication methods for electronic computing devices are subject to known scaling limits, confining the diversity of possible architectures. This work explores methods of fabricating a self-organized complex device known as an atomic switch network and discusses its potential utility in computing. Through a merger of top-down and bottom-up techniques guided by mathematical and nanoarchitectonic design principles, we have produced functional devices comprising nanoscale elements whose intrinsic nonlinear dynamics and memorization capabilities produce robust patterns of distributed activity and a capacity for nonlinear transformation of input signals when configured in the appropriate network architecture. Their operational characteristics represent a unique potential for hardware implementation of natural computation, specifically in the area of reservoir computing-a burgeoning field that investigates the computational aptitude of complex biologically inspired systems.

Two- and three-dimensional folding of thin film single-crystalline silicon for photovoltaic power applications.

PubMed

Guo, Xiaoying; Li, Huan; Ahn, Bok Yeop; Duoss, Eric B; Hsia, K Jimmy; Lewis, Jennifer A; Nuzzo, Ralph G

2009-12-01

Fabrication of 3D electronic structures in the micrometer-to-millimeter range is extremely challenging due to the inherently 2D nature of most conventional wafer-based fabrication methods. Self-assembly, and the related method of self-folding of planar patterned membranes, provide a promising means to solve this problem. Here, we investigate self-assembly processes driven by wetting interactions to shape the contour of a functional, nonplanar photovoltaic (PV) device. A mechanics model based on the theory of thin plates is developed to identify the critical conditions for self-folding of different 2D geometrical shapes. This strategy is demonstrated for specifically designed millimeter-scale silicon objects, which are self-assembled into spherical, and other 3D shapes and integrated into fully functional light-trapping PV devices. The resulting 3D devices offer a promising way to efficiently harvest solar energy in thin cells using concentrator microarrays that function without active light tracking systems.

Nanotube Film Electrode and an Electroactive Device Fabricated with the Nanotube Film Electrode and Methods for Making Same

NASA Technical Reports Server (NTRS)

Kang, Jin Ho (Inventor); Harrison, Joycelyn S. (Inventor); Park, Cheol (Inventor)

2017-01-01

Disclosed is a single wall carbon nanotube (SWCNT) film electrode (FE), all-organic electroactive device systems fabricated with the SWNT-FE, and methods for making same. The SWCNT can be replaced by other types of nanotubes. The SWCNT film can be obtained by filtering SWCNT solution onto the surface of an anodized alumina membrane. A freestanding flexible SWCNT film can be collected by breaking up this brittle membrane. The conductivity of this SWCNT film can advantageously be higher than 280 S/cm. An electroactive polymer (EAP) actuator layered with the SWNT-FE shows a higher electric field-induced strain than an EAP layered with metal electrodes because the flexible SWNT-FE relieves the restraint of the displacement of the polymeric active layer as compared to the metal electrode. In addition, if thin enough, the SWNT-FE is transparent in the visible light range, thus making it suitable for use in actuators used in optical devices.

Fabrication of π-type flexible thermoelectric generators using an electrochemical deposition method for thermal energy harvesting applications at room temperature

NASA Astrophysics Data System (ADS)

Trung, Nguyen Huu; Van Toan, Nguyen; Ono, Takahito

2017-12-01

Although the electrochemical deposition of thermoelectric materials is a potential method for applications such as flexible thermoelectric power generators (FTEGs), to date the use of this technique is limited. This paper demonstrates a new fabrication of self-supported π-type FTEGs using electrochemical deposition of thermoelectric materials. Two types of the devices based on Bi2Te3-Cu and Bi2Te3-Sb2Te3 have been fully completed and characterized. The Bi2Te3-Cu and Bi2Te3-Sb2Te3 devices consist of 24 pairs of thermocouples that can harvest thermal energy with output power densities of 1-4 µW cm-2 from temperature differences of approximately 2 °C-4 °C from the human body. The highly scalable and new devices demonstrated in this work open up opportunities for the applications of electrochemically deposited thermoelectric materials.

Application of electrochemical method to microfabricated region in single-crystal device of FeSe1- x Te x superconductors

NASA Astrophysics Data System (ADS)

Okada, Kazuhiro; Takagi, Tomohiro; Kobayashi, Masahiro; Ohnuma, Haruka; Noji, Takashi; Koike, Yoji; Ayukawa, Shin-ya; Kitano, Haruhisa

2018-04-01

The application of an electrochemical method to the iron-based chalcogenide superconductors has great potentials in enhancing their properties such as the superconducting transition temperature. Unfortunately, this method has been limited to polycrystalline powders or thin film samples with a large surface area. Here, we demonstrate that the electrochemical method can be usefully applied to single-crystal devices of FeSe1- x Te x superconductors by combining it with the focused ion beam (FIB) microfabrication techniques. Our results open a new route to developing the high-quality superconducting devices fabricated using layered iron-based chalcogenides, whose properties are electrochemically controlled.

A paper-based device for double-stranded DNA detection with Zif268

NASA Astrophysics Data System (ADS)

Zhang, Daohong

2017-05-01

Here, a small analytical device was fabricated on both nitrocellulose membrane and filter paper, for the detection of biotinylated double-stranded DNA (dsDNA) from 1 nM. Zif268 was utilized for capturing the target DNA, which was a zinc finger protein that recognized only a dsDNA with specific sequence. Therefore, this detection platform could be utilized for PCR result detection, with the well-designed primers (interpolate both biotin and Zif268 binding sequence). The result of the assay could be recorded by a camera-phone, and analyzed with software. The whole assay finished within 1 hour. Due to the easy fabrication, operation and disposal of this device, this method can be employed in point-of-care detection or on-site monitoring.

Development and fabrication of improved power transistor switches

NASA Technical Reports Server (NTRS)

Hower, P. L.; Chu, C. K.

1979-01-01

A new class of high-voltage power transistors was achieved by adapting present interdigitated thyristor processing techniques to the fabrication of npn Si transistors. Present devices are 2.3 cm in diameter and have V sub CEO (sus) in the range of 400 to 600V. V sub CEO (sus) = 450V devices were made with an (h sub FE)(I sub C) product of 900A at V sub CE = 2.5V. The electrical performance obtained was consistent with the predictions of an optimum design theory specifically developed for power switching transistors. The device design, wafer processing, and assembly techniques are described. Experimental measurements of the dc characteristics, forward SOA, and switching times are included. A new method of characterizing the switching performance of power transistors is proposed.

LiCoO2 and SnO2 Thin Film Electrodes for Lithium-Ion Battery Applications

NASA Technical Reports Server (NTRS)

Maranchi, Jeffrey P.; Hepp, Aloysius F.; Kumta, Prashant N.

2004-01-01

There is an increasing need for small dimension, ultra-lightweight, portable power supplies due to the miniaturization of consumer electronic devices. Rechargeable thin film lithium-ion batteries have the potential to fulfill the growing demands for micro-energy storage devices. However, rechargeable battery technology and fabrication processes have not kept paced with the advances made in device technology. Economical fabrication methods lending excellent microstructural and compositional control in the thin film battery electrodes have yet to be fully developed. In this study, spin coating has been used to demonstrate the flexibility of the approach to produce both anode (SnO2) and cathode (LiCoO2) thin films. Results on the microstructure crystal structure and electrochemical properties of the thin film electrodes are described and discussed.

Energy conversion device with support member having pore channels

DOEpatents

Routkevitch, Dmitri [Longmont, CO; Wind, Rikard A [Johnstown, CO

2014-01-07

Energy devices such as energy conversion devices and energy storage devices and methods for the manufacture of such devices. The devices include a support member having an array of pore channels having a small average pore channel diameter and having a pore channel length. Material layers that may include energy conversion materials and conductive materials are coaxially disposed within the pore channels to form material rods having a relatively small cross-section and a relatively long length. By varying the structure of the materials in the pore channels, various energy devices can be fabricated, such as photovoltaic (PV) devices, radiation detectors, capacitors, batteries and the like.

3D Printed Stretchable Tactile Sensors.

PubMed

Guo, Shuang-Zhuang; Qiu, Kaiyan; Meng, Fanben; Park, Sung Hyun; McAlpine, Michael C

2017-07-01

The development of methods for the 3D printing of multifunctional devices could impact areas ranging from wearable electronics and energy harvesting devices to smart prosthetics and human-machine interfaces. Recently, the development of stretchable electronic devices has accelerated, concomitant with advances in functional materials and fabrication processes. In particular, novel strategies have been developed to enable the intimate biointegration of wearable electronic devices with human skin in ways that bypass the mechanical and thermal restrictions of traditional microfabrication technologies. Here, a multimaterial, multiscale, and multifunctional 3D printing approach is employed to fabricate 3D tactile sensors under ambient conditions conformally onto freeform surfaces. The customized sensor is demonstrated with the capabilities of detecting and differentiating human movements, including pulse monitoring and finger motions. The custom 3D printing of functional materials and devices opens new routes for the biointegration of various sensors in wearable electronics systems, and toward advanced bionic skin applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel shock and heat tolerant gyrosensor utilizing a one-port surface acoustic wave reflective delay line

NASA Astrophysics Data System (ADS)

Oh, Haekwan; Fu, Chen; Yang, Sang Sik; Wang, Wen; Lee, Keekeun

2012-04-01

A surface acoustic wave (SAW)-based gyroscope with an 80 MHz central frequency was fabricated on a 128° YX LiNbO3 piezoelectric substrate. The fabricated gyroscope is composed of a SAW resonator, metallic dots and a SAW reflective delay line. The SAW resonator, which is activated by a voltage-controlled oscillator, generates a stable standing wave with a large amplitude at an 80 MHz resonant frequency, and the metallic dots induce a Coriolis force and generate a secondary SAW in the direction orthogonal to the propagating standing wave. The SAW reflective delay line is employed to measure the Coriolis effect by analyzing the deviations in the resonant frequency of the SAW reflective delay line. A combined finite element method/boundary element method was utilized to extract the optimal device parameters prior to fabrication. The device was fabricated according to the modeling results and then measured on a rate table. When the device was subjected to an angular rotation, a secondary SAW from the vibrating metallic dots was generated owing to the Coriolis force, resulting in a perturbation of the propagating SAW in the SAW reflective delay line. Depending on the angular velocity, the reflection peak of SAW reflective delay line was changed linearly, and this change was measured by the network analyzer. The measured results matched the modeling results well. The obtained sensitivity was approximately 1.23 deg/(deg/s) in an angular rate range of 0-2000 deg s-1. Good thermal and shock stabilities were observed during the evaluation process proving the shock and heat robustness of the fabricated SAW gyroscope.

Wafer bonded virtual substrate and method for forming the same

DOEpatents

Atwater, Jr., Harry A.; Zahler, James M [Pasadena, CA; Morral, Anna Fontcuberta i [Paris, FR

2007-07-03

A method of forming a virtual substrate comprised of an optoelectronic device substrate and handle substrate comprises the steps of initiating bonding of the device substrate to the handle substrate, improving or increasing the mechanical strength of the device and handle substrates, and thinning the device substrate to leave a single-crystal film on the virtual substrate such as by exfoliation of a device film from the device substrate. The handle substrate is typically Si or other inexpensive common substrate material, while the optoelectronic device substrate is formed of more expensive and specialized electro-optic material. Using the methodology of the invention a wide variety of thin film electro-optic materials of high quality can be bonded to inexpensive substrates which serve as the mechanical support for an optoelectronic device layer fabricated in the thin film electro-optic material.

Wafer bonded virtual substrate and method for forming the same

NASA Technical Reports Server (NTRS)

Atwater, Jr., Harry A. (Inventor); Zahler, James M. (Inventor); Morral, Anna Fontcuberta i (Inventor)

2007-01-01

A method of forming a virtual substrate comprised of an optoelectronic device substrate and handle substrate comprises the steps of initiating bonding of the device substrate to the handle substrate, improving or increasing the mechanical strength of the device and handle substrates, and thinning the device substrate to leave a single-crystal film on the virtual substrate such as by exfoliation of a device film from the device substrate. The handle substrate is typically Si or other inexpensive common substrate material, while the optoelectronic device substrate is formed of more expensive and specialized electro-optic material. Using the methodology of the invention a wide variety of thin film electro-optic materials of high quality can be bonded to inexpensive substrates which serve as the mechanical support for an optoelectronic device layer fabricated in the thin film electro-optic material.

Novel optical interconnect devices applying mask-transfer self-written method

NASA Astrophysics Data System (ADS)

Ishizawa, Nobuhiko; Matsuzawa, Yusuke; Tokiwa, Yu; Nakama, Kenichi; Mikami, Osamu

2012-01-01

The introduction of optical interconnect technology is expected to solve problems of conventional electric wiring. One of the promising technologies realizing optical interconnect is the self-written waveguide (SWW) technology with lightcurable resin. We have developed a new technology of the "Mask-Transfer Self-Written (MTSW)" method. This new method enables fabrication of arrayed M x N optical channels at one shot of UV-light. Using this technology, several new optical interconnect devices and connection technologies have been proposed and investigated. In this paper, first, we introduce MTSW method briefly. Next, we show plug-in alignment approach using optical waveguide plugs (OWP) and a micro-hole array (MHA) which are made of the light-curable resin. Easy and high efficiency plug-in alignment between fibers and an optoelectronic-printed wiring board (OE-PWB), between a fiber and a VCSEL, so on will be feasible. Then, we propose a new three-dimensional (3D) branch waveguide. By controlling the irradiating angle through the photomask aperture, it will be possible to fabricate 2-branch and 4-branch waveguides with a certain branch angle. The 3D branch waveguide will be very promising in the future optical interconnects and coupler devices of the multicore optical fiber.

Toward mass producible ordered bulk heterojunction organic photovoltaic devices.

PubMed

Kim, Taeyong; Yoon, Hyunsik; Song, Hyung-Jun; Haberkorn, Niko; Cho, Younghyun; Sung, Seung Hyun; Lee, Chang Hee; Char, Kookheon; Theato, Patrick

2012-12-13

A strategy to fabricate nanostructured poly(3-hexylthiophene) (P3HT) films for organic photovoltaic (OPV) cells by a direct transfer method from a reusable soft replica mold is presented. The flexible polyfluoropolyether (PFPE) replica mold allows low-pressure and low- temperature process condition for the successful transfer of nanostructured P3HT films onto PEDOT/PSS-coated ITO substrates. To reduce the fabrication cost of masters in large area, we employed well-ordered anodic aluminum oxide (AAO) as a template. Also, we provide a method to fabricate reversed nanostructures by exploiting the self-replication of replica molds. The concept of the transfer method in low temperature with a flexible and reusable replica mold obtained from an AAO template will be a firm foundation for a low-cost fabrication process of ordered OPVs. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Athermal and wavelength-trimmable photonic filters based on TiO₂-cladded amorphous-SOI.

PubMed

Lipka, Timo; Moldenhauer, Lennart; Müller, Jörg; Trieu, Hoc Khiem

2015-07-27

Large-scale integrated silicon photonic circuits suffer from two inevitable issues that boost the overall power consumption. First, fabrication imperfections even on sub-nm scale result in spectral device non-uniformity that require fine-tuning during device operation. Second, the photonic devices need to be actively corrected to compensate thermal drifts. As a result significant amount of power is wasted if no athermal and wavelength-trimmable solutions are utilized. Consequently, in order to minimize the total power requirement of photonic circuits in a passive way, trimming methods are required to correct the device inhomogeneities from manufacturing and athermal solutions are essential to oppose temperature fluctuations of the passive/active components during run-time. We present an approach to fabricate CMOS backend-compatible and athermal passive photonic filters that can be corrected for fabrication inhomogeneities by UV-trimming based on low-loss amorphous-SOI waveguides with TiO2 cladding. The trimming of highly confined 10 μm ring resonators is proven over a free spectral range retaining athermal operation. The athermal functionality of 2nd-order 5 μm add/drop microrings is demonstrated over 40°C covering a broad wavelength interval of 60 nm.

3D printed stretchable capacitive sensors for highly sensitive tactile and electrochemical sensing

NASA Astrophysics Data System (ADS)

Li, Kai; Wei, Hong; Liu, Wenguang; Meng, Hong; Zhang, Peixin; Yan, Chaoyi

2018-05-01

Developments of innovative strategies for the fabrication of stretchable sensors are of crucial importance for their applications in wearable electronic systems. In this work, we report the successful fabrication of stretchable capacitive sensors using a novel 3D printing method for highly sensitive tactile and electrochemical sensing applications. Unlike conventional lithographic or templated methods, the programmable 3D printing technique can fabricate complex device structures in a cost-effective and facile manner. We designed and fabricated stretchable capacitive sensors with interdigital and double-vortex designs and demonstrated their successful applications as tactile and electrochemical sensors. Especially, our stretchable sensors exhibited a detection limit as low as 1 × 10-6 M for NaCl aqueous solution, which could have significant potential applications when integrated in electronics skins.

3D printed stretchable capacitive sensors for highly sensitive tactile and electrochemical sensing.

PubMed

Li, Kai; Wei, Hong; Liu, Wenguang; Meng, Hong; Zhang, Peixin; Yan, Chaoyi

2018-05-04

Developments of innovative strategies for the fabrication of stretchable sensors are of crucial importance for their applications in wearable electronic systems. In this work, we report the successful fabrication of stretchable capacitive sensors using a novel 3D printing method for highly sensitive tactile and electrochemical sensing applications. Unlike conventional lithographic or templated methods, the programmable 3D printing technique can fabricate complex device structures in a cost-effective and facile manner. We designed and fabricated stretchable capacitive sensors with interdigital and double-vortex designs and demonstrated their successful applications as tactile and electrochemical sensors. Especially, our stretchable sensors exhibited a detection limit as low as 1 × 10 -6 M for NaCl aqueous solution, which could have significant potential applications when integrated in electronics skins.

Material and fabrication strategies for artificial muscles (Conference Presentation)

NASA Astrophysics Data System (ADS)

Spinks, Geoffrey M.

2017-04-01

Soft robotic and wearable robotic devices seek to exploit polymer based artificial muscles and sensor materials to generate biomimetic movements and forces. A challenge is to integrate the active materials into a complex, three-dimensional device with integrated electronics, power supplies and support structures. Both 3D printing and textiles technologies offer attractive fabrication strategies, but require suitable functional materials. 3D printing of actuating hydrogels has been developed to produce simple devices, such as a prototype valve. Tough hydrogels based on interpenetrating networks of ionicially crosslinked alginate and covalently crosslinked polyacrylamide and poly(N-isopropylacrylamide) have been developed in a form suitable for extrusion printing with UV curing. Combined with UV-curable and extrudable rigid acrylated urethanes, the tough hydrogels can be 3D printed into composite materials or complex shapes with multiple different materials. An actuating valve was printed that operated thermally to open or close the flow path using 6 parallel hydrogel actuators. Textile processing methods such as knitting and weaving can be used to generate assemblies of actuating fibres. Low cost and high performance coiled fibres made from oriented polymers have been used for developing actuating textiles. Similarly, braiding methods have been developed to fabricate new forms of McKibben muscles that operate without any external apparatus, such as pumps, compressors or piping.

Silicon photonics: Design, fabrication, and characterization of on-chip optical interconnects

NASA Astrophysics Data System (ADS)

Hsieh, I.-Wei

In recent years, the research field of silicon photonics has been developing rapidly from a concept to a demonstrated technology, and has gathered much attention from both academia and industry communities. Its many potential applications in long-haul telecommunication, mid-range data-communication, on-chip optical interconnection networks, and nano-scale sensing as well as its compatibility with electronic integrated circuits have driven much effort in realizing silicon photonics both as a disruptive technology for existing markets and as an enabling technology for new ones. Despite the promising future of silicon photonics, many fundamental issues still remain to be understood---both in the linear- and nonlinear-optical regimes. There are also many engineering challenges to make silicon photonics the gold standard in photonic integrated circuits. In this thesis, we focus on the design, fabrication, and characterization of active and passive silicon-on-insulator (SOI) photonic devices. The SOI material system differs from most conventional optical material platforms because of its high-refractive-index-contrast, which enables engineers to design very compact integrated photonic networks with sub-micron transverse waveguide dimensions and sharp bends. On the other hand, because most analytical formulas for designing waveguide devices are valid only in low-index-contrast cases, SOI photonic devices need to be analyzed numerically for accurate results. The second chapter of this thesis describes some common numerical methods such as Beam Propagation Method (BPM) and Finite Element Method (FEM) for waveguide-design simulations, and presents two design studies based on these methods. The compatibility of silicon photonic integrated circuits with conventional CMOS fabrication technology is another important aspect that distinguishes silicon photonics from others such as III-V materials and lithium niobate. However, the requirements for fabricating silicon photonic devices are quite different from those of electronic devices. Minimizing propagation losses by reducing sidewall roughness to nanometer scale over a device length of several millimeters or even centimeters has prompted researchers in academia and industry to refine the fabrication process. Chapter 3 of this thesis summarizes our efforts in fabricating silicon photonic devices using standard CMOS technology. Chapter 4 describes the characterization of nonlinear effects, including self-phase modulation (SPM), cross-phase modulation (XPM), and supercontinuum generation in silicon-wire waveguides. Silicon-wire waveguides are strip waveguides with submicron transverse dimensions, which allow strong light confinement inside the silicon core. This strong optical confinement, in addition to the large third-order nonlinear optical susceptibility of crystalline silicon, leads to a net nonlinearity which is several orders of magnitude higher than the nonlinearity of silica fiber. Significant nonlinear effects can be observed and characterized over a device length of only several millimeters in silicon wires with very small input power. These effects provide opportunities for engineers to design active silicon photonic devices which are compact and energy-efficient. Chapter 5 presents a realization of an integrated SOI optical isolator, which is a critical yet often overlooked component in photonic integrated circuits. This study shows the feasibility to make a hybrid garnet/SOI active device with very promising results. Finally, Chapter 6 summarizes our demonstration of transmitting terabit-scale data streams in silicon-wire waveguides, which is an important first-step towards enabling intra-chip interconnection networks with ultra-high bandwidths. Although the scope of this thesis is limited to providing only fractional views of the whole silicon photonics area, it provides enough references for interested readers to conduct further literature research in other aspects of silicon photonics. It is the author's hope that the thesis would convey to its readers the significance and potential of this exciting emerging technology.

Simple and inexpensive micromachined aluminum microfluidic devices for acoustic focusing of particles and cells.

PubMed

Gautam, Gayatri P; Burger, Tobias; Wilcox, Andrew; Cumbo, Michael J; Graves, Steven W; Piyasena, Menake E

2018-05-01

We introduce a new method to construct microfluidic devices especially useful for bulk acoustic wave (BAW)-based manipulation of cells and microparticles. To obtain efficient acoustic focusing, BAW devices require materials that have high acoustic impedance mismatch relative to the medium in which the cells/microparticles are suspended and materials with a high-quality factor. To date, silicon and glass have been the materials of choice for BAW-based acoustofluidic channel fabrication. Silicon- and glass-based fabrication is typically performed in clean room facilities, generates hazardous waste, and can take several hours to complete the microfabrication. To address some of the drawbacks in fabricating conventional BAW devices, we explored a new approach by micromachining microfluidic channels in aluminum substrates. Additionally, we demonstrate plasma bonding of poly(dimethylsiloxane) (PDMS) onto micromachined aluminum substrates. Our goal was to achieve an approach that is both low cost and effective in BAW applications. To this end, we micromachined aluminum 6061 plates and enclosed the systems with a thin PDMS cover layer. These aluminum/PDMS hybrid microfluidic devices use inexpensive materials and are simply constructed outside a clean room environment. Moreover, these devices demonstrate effectiveness in BAW applications as demonstrated by efficient acoustic focusing of polystyrene microspheres, bovine red blood cells, and Jurkat cells and the generation of multiple focused streams in flow-through systems. Graphical abstract The aluminum acoustofluidic device and the generation of multinode focusing of particles.

Solid electrolyte-electrode system for an electrochemical cell

DOEpatents

Tuller, H.L.; Kramer, S.A.; Spears, M.A.

1995-04-04

An electrochemical device including a solid electrolyte and solid electrode composed of materials having different chemical compositions and characterized by different electrical properties but having the same crystalline phase is provided. A method for fabricating an electrochemical device having a solid electrode and solid electrolyte characterized by the same crystalline phase is also provided. 17 figures.

Fabric Organic Electrochemical Transistors for Biosensors.

PubMed

Yang, Anneng; Li, Yuanzhe; Yang, Chenxiao; Fu, Ying; Wang, Naixiang; Li, Li; Yan, Feng

2018-06-01

Flexible fabric biosensors can find promising applications in wearable electronics. However, high-performance fabric biosensors have been rarely reported due to many special requirements in device fabrication. Here, the preparation of organic electrochemical transistors (OECTs) on Nylon fibers is reported. By introducing metal/conductive polymer multilayer electrodes on the fibers, the OECTs show very stable performance during bending tests. The devices with functionalized gates are successfully used as various biosensors with high sensitivity and selectivity. The fiber-based OECTs are woven together with cotton yarns successfully by using a conventional weaving machine, resulting in flexible and stretchable fabric biosensors with high performance. The fabric sensors show much more stable signals in the analysis of moving aqueous solutions than planar devices due to a capillary effect in fabrics. The fabric devices are integrated in a diaper and remotely operated by using a mobile phone, offering a unique platform for convenient wearable healthcare monitoring. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Three-dimensional plotter technology for fabricating polymeric scaffolds with micro-grooved surfaces.

PubMed

Son, JoonGon; Kim, GeunHyung

2009-01-01

Various mechanical techniques have been used to fabricate biomedical scaffolds, including rapid prototyping (RP) devices that operate from CAD files of the target feature information. The three-dimensional (3-D) bio-plotter is one RP system that can produce design-based scaffolds with good mechanical properties for mimicking cartilage and bones. However, the scaffolds fabricated by RP have very smooth surfaces, which tend to discourage initial cell attachment. Initial cell attachment, migration, differentiation and proliferation are strongly dependent on the chemical and physical characteristics of the scaffold surface. In this study, we propose a new 3-D plotting method supplemented with a piezoelectric system for fabricating surface-modified scaffolds. The effects of the physically-modified surface on the mechanical and hydrophilic properties were investigated, and the results of cell culturing of chondrocytes indicate that this technique is a feasible new method for fabricating high-quality 3-D polymeric scaffolds.

Photonic devices on planar and curved substrates and methods for fabrication thereof

DOEpatents

Bartl, Michael H.; Barhoum, Moussa; Riassetto, David

2016-08-02

A versatile and rapid sol-gel technique for the fabrication of high quality one-dimensional photonic bandgap materials. For example, silica/titania multi-layer materials may be fabricated by a sol-gel chemistry route combined with dip-coating onto planar or curved substrate. A shock-cooling step immediately following the thin film heat-treatment process is introduced. This step was found important in the prevention of film crack formation--especially in silica/titania alternating stack materials with a high number of layers. The versatility of this sol-gel method is demonstrated by the fabrication of various Bragg stack-type materials with fine-tuned optical properties by tailoring the number and sequence of alternating layers, the film thickness and the effective refractive index of the deposited thin films. Measured optical properties show good agreement with theoretical simulations confirming the high quality of these sol-gel fabricated optical materials.

Tribo-functionalizing Si and SU8 materials by surface modification for application in MEMS/NEMS actuator-based devices

NASA Astrophysics Data System (ADS)

Singh, R. A.; Satyanarayana, N.; Kustandi, T. S.; Sinha, S. K.

2011-01-01

Micro/nano-electro-mechanical-systems (MEMS/NEMS) are miniaturized devices built at micro/nanoscales. At these scales, the surface/interfacial forces are extremely strong and they adversely affect the smooth operation and the useful operating lifetimes of such devices. When these forces manifest in severe forms, they lead to material removal and thereby reduce the wear durability of the devices. In this paper, we present a simple, yet robust, two-step surface modification method to significantly enhance the tribological performance of MEMS/NEMS materials. The two-step method involves oxygen plasma treatment of polymeric films and the application of a nanolubricant, namely perfluoropolyether. We apply the two-step method to the two most important MEMS/NEMS structural materials, namely silicon and SU8 polymer. On applying surface modification to these materials, their initial coefficient of friction reduces by ~4-7 times and the steady-state coefficient of friction reduces by ~2.5-3.5 times. Simultaneously, the wear durability of both the materials increases by >1000 times. The two-step method is time effective as each of the steps takes the time duration of approximately 1 min. It is also cost effective as the oxygen plasma treatment is a part of the MEMS/NEMS fabrication process. The two-step method can be readily and easily integrated into MEMS/NEMS fabrication processes. It is anticipated that this method will work for any kind of structural material from which MEMS/NEMS are or can be made.

Contact planarization of ensemble nanowires

NASA Astrophysics Data System (ADS)

Chia, A. C. E.; LaPierre, R. R.

2011-06-01

The viability of four organic polymers (S1808, SC200, SU8 and Cyclotene) as filling materials to achieve planarization of ensemble nanowire arrays is reported. Analysis of the porosity, surface roughness and thermal stability of each filling material was performed. Sonication was used as an effective method to remove the tops of the nanowires (NWs) to achieve complete planarization. Ensemble nanowire devices were fully fabricated and I-V measurements confirmed that Cyclotene effectively planarizes the NWs while still serving the role as an insulating layer between the top and bottom contacts. These processes and analysis can be easily implemented into future characterization and fabrication of ensemble NWs for optoelectronic device applications.

Contact planarization of ensemble nanowires.

PubMed

Chia, A C E; LaPierre, R R

2011-06-17

The viability of four organic polymers (S1808, SC200, SU8 and Cyclotene) as filling materials to achieve planarization of ensemble nanowire arrays is reported. Analysis of the porosity, surface roughness and thermal stability of each filling material was performed. Sonication was used as an effective method to remove the tops of the nanowires (NWs) to achieve complete planarization. Ensemble nanowire devices were fully fabricated and I-V measurements confirmed that Cyclotene effectively planarizes the NWs while still serving the role as an insulating layer between the top and bottom contacts. These processes and analysis can be easily implemented into future characterization and fabrication of ensemble NWs for optoelectronic device applications.

Design architecture of double spiral interdigitated electrode with back gate electrode for biosensor application

NASA Astrophysics Data System (ADS)

Fathil, M. F. M.; Arshad, M. K. Md.; Hashim, U.; Ruslinda, A. R.; Gopinath, Subash C. B.; M. Nuzaihan M., N.; Ayub, R. M.; Adzhri, R.; Zaki, M.; Azman, A. H.

2016-07-01

This paper presents the preparation method of photolithography chrome mask design used in fabrication process of double spiral interdigitated electrode with back gate biasing based biosensor. By learning the fabrication process flow of the biosensor, the chrome masks are designed through drawing using the AutoCAD software. The overall width and length of the device is optimized at 7.0 mm and 10.0 mm, respectively. Fabrication processes of the biosensor required three chrome masks, which included back gate opening, spiral IDE formation, and passivation area formation. The complete chrome masks design will be sent for chrome mask fabrication and for future use in biosensor fabrication.

Fabrication and electrical characterization of a MOS memory device containing self-assembled metallic nanoparticles

NASA Astrophysics Data System (ADS)

Sargentis, Ch.; Giannakopoulos, K.; Travlos, A.; Tsamakis, D.

2007-04-01

Floating gate devices with nanoparticles embedded in dielectrics have recently attracted much attention due to the fact that these devices operate as non-volatile memories with high speed, high density and low power consumption. In this paper, memory devices containing gold (Au) nanoparticles have been fabricated using e-gun evaporation. The Au nanoparticles are deposited on a very thin SiO 2 layer and are then fully covered by a HfO 2 layer. The HfO 2 is a high- k dielectric and gives good scalability to the fabricated devices. We studied the effect of the deposition parameters to the size and the shape of the Au nanoparticles using capacitance-voltage and conductance-voltage measurements, we demonstrated that the fabricated device can indeed operate as a low-voltage memory device.

Fabrication of Long Period Gratings by Periodically Removing the Coating of Cladding-Etched Single Mode Optical Fiber Towards Optical Fiber Sensor Development.

PubMed

Ascorbe, Joaquin; Corres, Jesus M; Del Villar, Ignacio; Matias, Ignacio R

2018-06-07

Here, we present a novel method to fabricate long period gratings using standard single mode optical fibers (SMF). These optical devices were fabricated in a three-step process, which consisted of etching the SMF, then coating it with a thin-film and, the final step, which involved removing sections of the coating periodically by laser ablation. Tin dioxide was chosen as the material for this study and it was sputtered using a pulsed DC sputtering system. Theoretical simulations were performed in order to select the appropriate parameters for the experiments. The responses of two different devices to different external refractive indices was studied, and the maximum sensitivity obtained was 6430 nm/RIU for external refractive indices ranging from 1.37 to 1.39.

A front-end wafer-level microsystem packaging technique with micro-cap array

NASA Astrophysics Data System (ADS)

Chiang, Yuh-Min

2002-09-01

The back-end packaging process is the remaining challenge for the micromachining industry to commercialize microsystem technology (MST) devices at low cost. This dissertation presents a novel wafer level protection technique as a final step of the front-end fabrication process for MSTs. It facilitates improved manufacturing throughput and automation in package assembly, wafer level testing of devices, and enhanced device performance. The method involves the use of a wafer-sized micro-cap array, which consists of an assortment of small caps micro-molded onto a material with adjustable shapes and sizes to serve as protective structures against the hostile environments during packaging. The micro-cap array is first constructed by a micromachining process with micro-molding technique, then sealed to the device wafer at wafer level. Epoxy-based wafer-level micro cap array has been successfully fabricated and showed good compatibility with conventional back-end packaging processes. An adhesive transfer technique was demonstrated to seal the micro cap array with a MEMS device wafer. No damage or gross leak was observed while wafer dicing or later during a gross leak test. Applications of the micro cap array are demonstrated on MEMS, microactuators fabricated using CRONOS MUMPS process. Depending on the application needs, the micro-molded cap can be designed and modified to facilitate additional component functions, such as optical, electrical, mechanical, and chemical functions, which are not easily achieved in the device by traditional means. Successful fabrication of a micro cap array comprised with microlenses can provide active functions as well as passive protection. An optical tweezer array could be one possibility for applications of a micro cap with microlenses. The micro cap itself could serve as micro well for DNA or bacteria amplification as well.

Draw your assay: Fabrication of low-cost paper-based diagnostic and multi-well test zones by drawing on a paper.

PubMed

Oyola-Reynoso, Stephanie; Heim, Andrew P; Halbertsma-Black, Julian; Zhao, C; Tevis, Ian D; Çınar, Simge; Cademartiri, Rebecca; Liu, Xinyu; Bloch, Jean-Francis; Thuo, Martin M

2015-11-01

Interest in low-cost diagnostic devices has recently gained attention, in part due to the rising cost of healthcare and the need to serve populations in resource-limited settings. A major challenge in the development of such devices is the need for hydrophobic barriers to contain polar bio-fluid analytes. Key approaches in lowering the cost in diagnostics have centered on (i) development of low-cost fabrication techniques/processes, (ii) use of affordable materials, or, (iii) minimizing the need for high-tech tools. This communication describes a simple, low-cost, adaptable, and portable method for patterning paper and subsequent use of the patterned paper in diagnostic tests. Our approach generates hydrophobic regions using a ball-point pen filled with a hydrophobizing molecule suspended in a solvent carrier. An empty ball-point pen was filled with a solution of trichloro perfluoroalkyl silane in hexanes (or hexadecane), and the pen used to draw lines on Whatman® chromatography 1 paper. The drawn regions defined the test zones since the trichloro silane reacts with the paper to give a hydrophobic barrier. The formation of the hydrophobic barriers is reaction kinetic and diffusion-limited, ensuring well defined narrow barriers. We performed colorimetric glucose assays and enzyme-linked immuno-sorbent assay (ELISA) using the created test zones. To demonstrate the versatility of this approach, we fabricated multiple devices on a single piece of paper and demonstrated the reproducibility of assays on these devices. The overall cost of devices fabricated by drawing are relatively lower (

Microfabricated polyester conical microwells for cell culture applications†

PubMed Central

Selimović, Šeila; Piraino, Francesco; Bae, Hojae; Rasponi, Marco; Redaelli, Alberto

2012-01-01

Over the past few years there has been a great deal of interest in reducing experimental systems to a lab-on-a-chip scale. There has been particular interest in conducting high-throughput screening studies using microscale devices, for example in stem cell research. Microwells have emerged as the structure of choice for such tests. Most manufacturing approaches for microwell fabrication are based on photolithography, soft lithography, and etching. However, some of these approaches require extensive equipment, lengthy fabrication process, and modifications to the existing microwell patterns are costly. Here we show a convenient, fast, and low-cost method for fabricating microwells for cell culture applications by laser ablation of a polyester film coated with silicone glue. Microwell diameter was controlled by adjusting the laser power and speed, and the well depth by stacking several layers of film. By using this setup, a device containing hundreds of microwells can be fabricated in a few minutes to analyze cell behavior. Murine embryonic stem cells and human hepatoblastoma cells were seeded in polyester microwells of different sizes and showed that after 9 days in culture cell aggregates were formed without a noticeable deleterious effect of the polyester film and glue. These results show that the polyester microwell platform may be useful for cell culture applications. The ease of fabrication adds to the appeal of this device as minimal technological skill and equipment is required. PMID:21614380

Femtosecond Laser Fabrication of Monolithically Integrated Microfluidic Sensors in Glass

PubMed Central

He, Fei; Liao, Yang; Lin, Jintian; Song, Jiangxin; Qiao, Lingling; Cheng, Ya; Sugioka, Koji

2014-01-01

Femtosecond lasers have revolutionized the processing of materials, since their ultrashort pulse width and extremely high peak intensity allows high-quality micro- and nanofabrication of three-dimensional (3D) structures. This unique capability opens up a new route for fabrication of microfluidic sensors for biochemical applications. The present paper presents a comprehensive review of recent advancements in femtosecond laser processing of glass for a variety of microfluidic sensor applications. These include 3D integration of micro-/nanofluidic, optofluidic, electrofluidic, surface-enhanced Raman-scattering devices, in addition to fabrication of devices for microfluidic bioassays and lab-on-fiber sensors. This paper describes the unique characteristics of femtosecond laser processing and the basic concepts involved in femtosecond laser direct writing. Advanced spatiotemporal beam shaping methods are also discussed. Typical examples of microfluidic sensors fabricated using femtosecond lasers are then highlighted, and their applications in chemical and biological sensing are described. Finally, a summary of the technology is given and the outlook for further developments in this field is considered. PMID:25330047

Suspended sub-50 nm vanadium dioxide membrane transistors: fabrication and ionic liquid gating studies

NASA Astrophysics Data System (ADS)

Sim, Jai S.; Zhou, You; Ramanathan, Shriram

2012-10-01

We demonstrate a robust lithographic patterning method to fabricate self-supported sub-50 nm VO2 membranes that undergo a phase transition. Utilizing such self-supported membranes, we directly observed a shift in the metal-insulator transition temperature arising from stress relaxation and consistent opening of the hysteresis. Electric double layer transistors were then fabricated with the membranes and compared to thin film devices. The ionic liquid allowed reversible modulation of channel resistance and distinguishing bulk processes from the surface effects. From the shift in the metal-insulator transition temperature, the carrier density doped through electrolyte gating is estimated to be 1 × 1020 cm-3. Hydrogen annealing studies showed little difference in resistivity between the film and the membrane indicating rapid diffusion of hydrogen in the vanadium oxide rutile lattice consistent with previous observations. The ability to fabricate electrically-wired, suspended VO2 ultra-thin membranes creates new opportunities to study mesoscopic size effects on phase transitions and may also be of interest in sensor devices.

Reduced Dimensionality Lithium Niobate Microsystems

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

Eichenfield, Matt

2017-01-01

The following report describes work performed under the LDRD program at Sandia National Laboratories October 2014 and September 2016. The work presented demonstrates the ability of Sandia Labs to develop state-of-the-art photonic devices based on thin film lithium niobate (LiNbO 3 ). Section 1 provides an introduction to integrated LiNbO 3 devices and motivation for developing thin film nonlinear optical systems. Section 2 describes the design, fabrication, and photonic performance of thin film optical microdisks fabricated from bulk LiNbO 3 using a bulk implantation method developed at Sandia. Sections 3 and 4 describe the development of similar thin film LiNbOmore » 3 structures fabricated from LiNbO 3 on insulator (LNOI) substrates and our demonstration of optical frequency conversion with state-of-the-art efficiency. Finally, Section 5 describes similar microdisk resonators fabricated from LNOI wafers with a buried metal layer, in which we demonstrate electro-optic modulation.« less

Fabrication and optical characterization of silica optical fibers containing gold nanoparticles.

PubMed

de Oliveira, Rafael E P; Sjödin, Niclas; Fokine, Michael; Margulis, Walter; de Matos, Christiano J S; Norin, Lars

2015-01-14

Gold nanoparticles have been used since antiquity for the production of red-colored glasses. More recently, it was determined that this color is caused by plasmon resonance, which additionally increases the material's nonlinear optical response, allowing for the improvement of numerous optical devices. Interest in silica fibers containing gold nanoparticles has increased recently, aiming at the integration of nonlinear devices with conventional optical fibers. However, fabrication is challenging due to the high temperatures required for silica processing and fibers with gold nanoparticles were solely demonstrated using sol-gel techniques. We show a new fabrication technique based on standard preform/fiber fabrication methods, where nanoparticles are nucleated by heat in a furnace or by laser exposure with unprecedented control over particle size, concentration, and distribution. Plasmon absorption peaks exceeding 800 dB m(-1) at 514-536 nm wavelengths were observed, indicating higher achievable nanoparticle concentrations than previously reported. The measured resonant nonlinear refractive index, (6.75 ± 0.55) × 10(-15) m(2) W(-1), represents an improvement of >50×.

Advanced fabrication of Si nanowire FET structures by means of a parallel approach.

PubMed

Li, J; Pud, S; Mayer, D; Vitusevich, S

2014-07-11

In this paper we present fabricated Si nanowires (NWs) of different dimensions with enhanced electrical characteristics. The parallel fabrication process is based on nanoimprint lithography using high-quality molds, which facilitates the realization of 50 nm-wide NW field-effect transistors (FETs). The imprint molds were fabricated by using a wet chemical anisotropic etching process. The wet chemical etch results in well-defined vertical sidewalls with edge roughness (3σ) as small as 2 nm, which is about four times better compared with the roughness usually obtained for reactive-ion etching molds. The quality of the mold was studied using atomic force microscopy and scanning electron microscopy image data. The use of the high-quality mold leads to almost 100% yield during fabrication of Si NW FETs as well as to an exceptional quality of the surfaces of the devices produced. To characterize the Si NW FETs, we used noise spectroscopy as a powerful method for evaluating device performance and the reliability of structures with nanoscale dimensions. The Hooge parameter of fabricated FET structures exhibits an average value of 1.6 × 10(-3). This value reflects the high quality of Si NW FETs fabricated by means of a parallel approach that uses a nanoimprint mold and cost-efficient technology.

Laser Fabrication and Characterization of Adhesive-Free Joints for Encapsulation of Biomedical Implant Devices

DTIC Science & Technology

2005-01-01

excitation sources should be helpful in overcoming this problem. CONCLUSIONS Biocompatible joints between polyimide and titanium-coated borosilicate...Technology, 46025 Port St., Plymouth, MI 48170, U.S.A. ABSTRACT Laser-fabricated joints of sub-millimeter widths between biocompatible , dissimilar materials...method of a very promising system, polyimide /titanium-coated borosilicate glass, and present and discuss results from characterization of such laser

Method for fabricating photovoltaic device having improved short wavelength photoresponse

DOEpatents

Catalano, Anthony W.

1989-07-04

Amorphous p-i-n silicon photovoltaic cells with improved short wavelength photoresponse are fabricated with reduced p-dopant contamination at the p/i interface. Residual p-dopants are removed by flushing the deposition chamber with a gaseous mixture capable of reacting with excess doping contaminants prior to the deposition of the i-layer and subsequent to the deposition of the p-layer.

Plant virus directed fabrication of nanoscale materials and devices

DTIC Science & Technology

2015-03-26

stringent coating processes as well as yield novel materials with unique conductive and mesoscale structures (Fowler et al., 2001; Niu et al., 2007a...steel and then coated by ELD with conductive nickel or cobalt. Several fabrication methods including atomic layer deposition, sputtering, electro...novel columnar nanowire structure that when coatedwith conductive nickel provides a forest of nanoscale electrodes that can be coated with silicon by

Quality Control Method for a Micro-Nano-Channel Microfabricated Device

NASA Technical Reports Server (NTRS)

Grattoni, Alessandro; Ferrari, Mauro; Li, Xuewu

2012-01-01

A variety of silicon-fabricated devices is used in medical applications such as drug and cell delivery, and DNA and protein separation and analysis. When a fluidic device inlet is connected to a compressed gas reservoir, and the outlet is at a lower pressure, a gas flow occurs through the membrane toward the outside. The method relies on the measurement of the gas pressure over the elapsed time inside the upstream and downstream environments. By knowing the volume of the upstream reservoir, the gas flow rate through the membrane over the pressure drop can be calculated. This quality control method consists of measuring the gas flow through a device and comparing the results with a standard curve, which can be obtained by testing standard devices. Standard devices can be selected through a variety of techniques, both destructive and nondestructive, such as SEM, AFM, and standard particle filtration.

Micro-fabrication method of graphite mesa microdevices based on optical lithography technology

NASA Astrophysics Data System (ADS)

Zhang, Cheng; Wen, Donghui; Zhu, Huamin; Zhang, Xiaorui; Yang, Xing; Shi, Yunsheng; Zheng, Tianxiang

2017-12-01

Graphite mesa microdevices have incommensurate contact nanometer interfaces, superlubricity, high-speed self-retraction, and other characteristics, which have potential applications in high-performance oscillators and micro-scale switches, memory devices, and gyroscopes. However, the current method of fabricating graphite mesa microdevices is mainly based on high-cost, low efficiency electron beam lithography technology. In this paper, the processing technologies of graphite mesa microdevices with various shapes and sizes were investigated by a low-cost micro-fabrication method, which was mainly based on optical lithography technology. The characterization results showed that the optical lithography technology could realize a large-area of patterning on the graphite surface, and the graphite mesa microdevices, which have a regular shape, neat arrangement, and high verticality could be fabricated in large batches through optical lithography technology. The experiments and analyses showed that the graphite mesa microdevices fabricated through optical lithography technology basically have the same self-retracting characteristics as those fabricated through electron beam lithography technology, and the maximum size of the graphite mesa microdevices with self-retracting phenomenon can reach 10 µm  ×  10 µm. Therefore, the proposed method of this paper can realize the high-efficiency and low-cost processing of graphite mesa microdevices, which is significant for batch fabrication and application of graphite mesa microdevices.

Fabrication of rectangular cross-sectional microchannels on PMMA with a CO2 laser and underwater fabricated copper mask

NASA Astrophysics Data System (ADS)

Prakash, Shashi; Kumar, Subrata

2017-09-01

CO2 lasers are commonly used for fabricating polymer based microfluidic devices. Despite several key advantages like low cost, time effectiveness, easy to operate and no requirement of clean room facility, CO2 lasers suffer from few disadvantages like thermal bulging, improper dimensional control, difficulty to produce microchannels of other than Gaussian cross sectional shapes and inclined surface walls. Many microfluidic devices require square or rectangular cross-sections which are difficult to produce using normal CO2 laser procedures. In this work, a thin copper sheet of 40 μm was used as a mask above the PMMA (Polymethyl-methacrylate) substrate while fabricating the microchannels utilizing the raster scanning feature of the CO2 lasers. Microchannels with different width dimensions were fabricated utilizing a CO2 laser in with mask and without-mask conditions. A comparison of both the fabricating process has been made. It was found that microchannels with U shape cross section and rectangular cross-section can efficiently be produced using the with mask technique. In addition to this, this technique can provide perfect dimensional control and better surface quality of the microchannel walls. Such a microchannel fabrication process do not require any post-processing. The fabrication of mask using a nanosecond fiber laser has been discussed in details. An underwater laser fabrication method was adopted to overcome heat related defects in mask preparation. Overall, the technique was found to be easy to adopt and significant improvements were observed in microchannel fabrication.

Method for producing edge geometry superconducting tunnel junctions utilizing an NbN/MgO/NbN thin film structure

NASA Technical Reports Server (NTRS)

Hunt, Brian D. (Inventor); Leduc, Henry G. (Inventor)

1992-01-01

A method for fabricating an edge geometry superconducting tunnel junction device is discussed. The device is comprised of two niobium nitride superconducting electrodes and a magnesium oxide tunnel barrier sandwiched between the two electrodes. The NbN electrodes are preferably sputter-deposited, with the first NbN electrode deposited on an insulating substrate maintained at about 250 C to 500 C for improved quality of the electrode.

Stainless steel pinholes for fast fabrication of high-performance microchip electrophoresis devices by CO2 laser ablation.

PubMed

Yap, Yiing C; Guijt, Rosanne M; Dickson, Tracey C; King, Anna E; Breadmore, Michael C

2013-11-05

With the introduction of hobby laser engravers/cutters, the use of CO2 laser micromachining on poly(methyl methacrylate) (PMMA) has the potential for flexible, low cost, rapid prototyping of microfluidic devices. Unfortunately, the feature size created by most entry-level CO2 laser micromachining systems is too large to become a functional tool in analytical microfluidics. In this paper, we report a novel method to reduce the feature size of microchannels and the bulges formed at the rim of the channel during CO2 laser micromachining by passing the laser beam through a stainless steel pinhole. Without the pinhole, the channel width was typically 300 μm wide. However, when 50 or 35 μm diameter pinholes were used, channel widths of 60 and 25 μm, respectively, could be obtained. The height of the bulge deposited directly next to the channel was reduced to less than 0.8 μm with the pinhole during ablation. Separations of fluorescent dyes on devices ablated with and without the pinhole were compared. On devices fabricated with the pinhole, the number of theoretical plates/m was 2.2-fold higher compared to devices fabricated without the pinhole, and efficiencies comparable to embossed PMMA and laser ablated glass chips were obtained. A mass-produced commercial hobby laser (retailing at ∼$2500), when equipped with a $500 pinhole, represents a rapid and low-cost approach to the rapid fabrication of rigid plastic microchips including the narrow microchannels required for microchip electrophoresis.

Conductivity based on selective etch for GaN devices and applications thereof

DOEpatents

Zhang, Yu; Sun, Qian; Han, Jung

2015-12-08

This invention relates to methods of generating NP gallium nitride (GaN) across large areas (>1 cm.sup.2) with controlled pore diameters, pore density, and porosity. Also disclosed are methods of generating novel optoelectronic devices based on porous GaN. Additionally a layer transfer scheme to separate and create free-standing crystalline GaN thin layers is disclosed that enables a new device manufacturing paradigm involving substrate recycling. Other disclosed embodiments of this invention relate to fabrication of GaN based nanocrystals and the use of NP GaN electrodes for electrolysis, water splitting, or photosynthetic process applications.

Encapsulants for protecting MEMS devices during post-packaging release etch

DOEpatents

Peterson, Kenneth A.

2005-10-18

The present invention relates to methods to protect a MEMS or microsensor device through one or more release or activation steps in a "package first, release later" manufacturing scheme: This method of fabrication permits wirebonds, other interconnects, packaging materials, lines, bond pads, and other structures on the die to be protected from physical, chemical, or electrical damage during the release etch(es) or other packaging steps. Metallic structures (e.g., gold, aluminum, copper) on the device are also protected from galvanic attack because they are protected from contact with HF or HCL-bearing solutions.

Method of making high breakdown voltage semiconductor device

DOEpatents

Arthur, Stephen D.; Temple, Victor A. K.

1990-01-01

A semiconductor device having at least one P-N junction and a multiple-zone junction termination extension (JTE) region which uniformly merges with the reverse blocking junction is disclosed. The blocking junction is graded into multiple zones of lower concentration dopant adjacent termination to facilitate merging of the JTE to the blocking junction and placing of the JTE at or near the high field point of the blocking junction. Preferably, the JTE region substantially overlaps the graded blocking junction region. A novel device fabrication method is also provided which eliminates the prior art step of separately diffusing the JTE region.

Self-assembled nanostructured resistive switching memory devices fabricated by templated bottom-up growth

PubMed Central

Song, Ji-Min; Lee, Jang-Sik

2016-01-01

Metal-oxide-based resistive switching memory device has been studied intensively due to its potential to satisfy the requirements of next-generation memory devices. Active research has been done on the materials and device structures of resistive switching memory devices that meet the requirements of high density, fast switching speed, and reliable data storage. In this study, resistive switching memory devices were fabricated with nano-template-assisted bottom up growth. The electrochemical deposition was adopted to achieve the bottom-up growth of nickel nanodot electrodes. Nickel oxide layer was formed by oxygen plasma treatment of nickel nanodots at low temperature. The structures of fabricated nanoscale memory devices were analyzed with scanning electron microscope and atomic force microscope (AFM). The electrical characteristics of the devices were directly measured using conductive AFM. This work demonstrates the fabrication of resistive switching memory devices using self-assembled nanoscale masks and nanomateirals growth from bottom-up electrochemical deposition. PMID:26739122

Method of fabricating reflection-mode EUV diffusers

DOEpatents

Anderson, Erik; Naulleau, Patrick P.

2005-03-01

Techniques for fabricating well-controlled, random relief, engineered surfaces that serve as substrates for EUV optical devices are accomplished with grayscale exposure. The method of fabricating a multilevel EUV optical element includes: (a) providing a substrate; (b) depositing a layer of curable material on a surface of the substrate; (c) creating a relief profile in a layer of cured material from the layer of curable material wherein the relief profile comprises multiple levels of cured material that has a defined contour; and (d) depositing a multilayer reflection film over the relief profile wherein the film has an outer contour that substantially matches that of the relief profile. The curable material can comprise photoresist or a low dielectric constant material.

Method for making an electrochemical cell

DOEpatents

Bates, John B.; Dudney, Nancy J.

1996-01-01

Described is a thin-film battery, especially a thin-film microbattery, and a method for making same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode Configured as a microbattery, the battery can be fabricated directly onto a semiconductor chip, onto the semiconductor die or onto any portion of the chip carrier. The battery can be fabricated to any specified size or shape to meet the requirements of a particular application. The battery is fabricated of solid state materials and is capable of operation between -15.degree. C. and 150.degree. C.

Fabrication process for polymer PLC platforms with V-grooves for passive alignment

NASA Astrophysics Data System (ADS)

Park, Suntak; Lee, Jong-Moo; Ahn, Joon Tae; Baek, Yong-Soon

2005-12-01

A method for polymer planar lightwave circuit (PLC) devices fabricated on a substrate with V-grooves is developed for passive alignment of an optical fiber to a polymer waveguide. In order to minimize thickness nonuniformity of polymer layers caused by the V-grooves, dry film resist (DFR) is used. The V-grooves are covered with the DFR before the polymer layers are spin-coated on the substrate. The DFR prevents the polymer from being filled in the V-grooves as well as from being spin-coated nonuniformly on the substrate. This process provides a simple and cost-effective fabrication method of polymer PLCs or platforms for passive alignment.

A general strategy for hybrid thin film fabrication and transfer onto arbitrary substrates.

PubMed

Zhang, Yong; Magan, John J; Blau, Werner J

2014-04-28

The development of thin film-based structures/devices often requires thin films to be transferred onto arbitrary substrates/surfaces. Controllable and non-destructive transfer method, although highly desired, remains quite challenging. Here we report a general method for fabrication and transfer of hybrid (ultra)thin films. The proposed solution-based in-situ transfer method shows not only its robust ability for thin film transfer onto arbitrary substrates but also its highly controlled and non-destructive characteristic. With a hole structure as the support, fully-stretched free-standing thin film is prepared. The successful transfer to a curved surface demonstrates the possibility for production of thin film-coated complex optical components. Ultrathin (35 nm) hybrid film transferred onto PET (50 μm thick) shows high transparency (>90% in visible range), conductivity (1.54 × 10(4) S/m), and flexibility (radius of curvature down to mm scale). The reported transfer method would provide a powerful route towards complex thin film-based structures/devices.

A General Strategy for Hybrid Thin Film Fabrication and Transfer onto Arbitrary Substrates

PubMed Central

Zhang, Yong; Magan, John J.; Blau, Werner J.

2014-01-01

The development of thin film-based structures/devices often requires thin films to be transferred onto arbitrary substrates/surfaces. Controllable and non-destructive transfer method, although highly desired, remains quite challenging. Here we report a general method for fabrication and transfer of hybrid (ultra)thin films. The proposed solution-based in-situ transfer method shows not only its robust ability for thin film transfer onto arbitrary substrates but also its highly controlled and non-destructive characteristic. With a hole structure as the support, fully-stretched free-standing thin film is prepared. The successful transfer to a curved surface demonstrates the possibility for production of thin film-coated complex optical components. Ultrathin (35 nm) hybrid film transferred onto PET (50 μm thick) shows high transparency (>90% in visible range), conductivity (1.54 × 104 S/m), and flexibility (radius of curvature down to mm scale). The reported transfer method would provide a powerful route towards complex thin film-based structures/devices. PMID:24769689

Fabrication of high quality aspheric microlens array by dose-modulated lithography and surface thermal reflow

NASA Astrophysics Data System (ADS)

Huang, Shengzhou; Li, Mujun; Shen, Lianguan; Qiu, Jinfeng; Zhou, Youquan

2018-03-01

A novel fabrication method for high quality aspheric microlens array (MLA) was developed by combining the dose-modulated DMD-based lithography and surface thermal reflow process. In this method, the complex shape of aspheric microlens is pre-modeled via dose modulation in a digital micromirror device (DMD) based maskless projection lithography. And the dose modulation mainly depends on the distribution of exposure dose of photoresist. Then the pre-shaped aspheric microlens is polished by a following non-contact thermal reflow (NCTR) process. Different from the normal process, the reflow process here is investigated to improve the surface quality while keeping the pre-modeled shape unchanged, and thus will avoid the difficulties in generating the aspheric surface during reflow. Fabrication of a designed aspheric MLA with this method was demonstrated in experiments. Results showed that the obtained aspheric MLA was good in both shape accuracy and surface quality. The presented method may be a promising approach in rapidly fabricating high quality aspheric microlens with complex surface.

Fabrication and testing of unileg oxide thermoelectric device

NASA Astrophysics Data System (ADS)

Sharma, Jyothi; Purohit, R. D.; Prakash, Deep; Sinha, P. K.

2017-05-01

A prototype of oxide thermoelectric unileg device was fabricated. This device was based on only n-legs made of La doped calcium manganate. The powder was synthesized, characterised and consolidated in rectangular thermoelements. A 3×3 device was fabricated by fitting 9 rectangular bars in alumina housing and connected by silver strips. The device has been tested under large temperature difference (ΔT=480°C) using an indegenous system. An open circuit voltage of 468 mV was obtained for a nine leg `unileg' device. The device exhibits a internal resistance of ˜1Ω. The maximum power output for this nine leg device reached upto 50 mW in these working condition.

Growth and characterization of zinc oxide and PZT films for micromachined acoustic wave devices

NASA Astrophysics Data System (ADS)

Yoon, Sang Hoon

The ability to detect the presence of low concentrations of harmful substances, such as biomolecular agents, warfare agents, and pathogen cells, in our environment and food chain would greatly advance our safety, provide more sensitive tools for medical diagnostics, and protect against terrorism. Acoustic wave (AW) devices have been widely studied for such applications due to several attractive properties, such as rapid response, reliability, portability, ease of use, and low cost. The principle of these sensors is based on a fundamental feature of the acoustic wave that is generated and detected by a piezoelectric material. The performance of the device, therefore, greatly depends on the properties of piezoelectric thin film. The required properties include a high piezoelectric coefficient and high electromechanical coefficients. The surface roughness and the mechanical properties, such as Young's modulus and hardness, are also factors that can affect the wave propagation of the device. Since the film properties are influenced by the structure of the material, understanding thin film structure is very important for the design of high-performance piezoelectric MEMS devices for biosensor applications. In this research, two piezoelectric thin film materials were fabricated and investigated. ZnO films were fabricated by CSD (Chemical Solution Deposition) and sputtering, and PZT films were fabricated by CSD only. The process parameters for solution derived ZnO and PZT films, such as the substrate type, the effect of the chelating agent, and heat treatment, were studied to find the relationship between process parameters and thin film structure. In the case of the sputtered ZnO films, the process gas types and their ratio, heat treatment in situ, and post deposition were investigated. The key results of systematic experiments show that the combined influence of chemical modifiers and substrates in chemical solution deposition have an effect on the crystallographic orientation of the films, which is explained by the phase transformation that occurs from amorphous pyrolized film to crystalline film. Sputtered ZnO films do not show a strong dependence on the parameters, possibly indicating a reduced energy barrier for the growth of ZnO film due to plasma energy. Based on an understanding of the relationship between process and thin film structure, the growth mechanism of CSD ZnO is proposed. The devices are fabricated on 4-inch silicon wafers by a microelectronic fabrication method. The fabrication procedure and issues relating to device fabrication are discussed.

Melding Vapor-Phase Organic Chemistry and Textile Manufacturing To Produce Wearable Electronics.

PubMed

Andrew, Trisha L; Zhang, Lushuai; Cheng, Nongyi; Baima, Morgan; Kim, Jae Joon; Allison, Linden; Hoxie, Steven

2018-04-17

Body-mountable electronics and electronically active garments are the future of portable, interactive devices. However, wearable devices and electronic garments are demanding technology platforms because of the large, varied mechanical stresses to which they are routinely subjected, which can easily abrade or damage microelectronic components and electronic interconnects. Furthermore, aesthetics and tactile perception (or feel) can make or break a nascent wearable technology, irrespective of device metrics. The breathability and comfort of commercial fabrics is unmatched. There is strong motivation to use something that is already familiar, such as cotton/silk thread, fabrics, and clothes, and imperceptibly adapt it to a new technological application. (24) Especially for smart garments, the intrinsic breathability, comfort, and feel of familiar fabrics cannot be replicated by devices built on metalized synthetic fabrics or cladded, often-heavy designer fibers. We propose that the strongest strategy to create long-lasting and impactful electronic garments is to start with a mass-produced article of clothing, fabric, or thread/yarn and coat it with conjugated polymers to yield various textile circuit components. Commonly available, mass-produced fabrics, yarns/threads, and premade garments can in theory be transformed into a plethora of comfortably wearable electronic devices upon being coated with films of electronically active conjugated polymers. The definitive hurdle is that premade garments, threads, and fabrics have densely textured, three-dimensional surfaces that display roughness over a large range of length scales, from microns to millimeters. Tremendous variation in the surface morphology of conjugated-polymer-coated fibers and fabrics can be observed with different coating or processing conditions. In turn, the morphology of the conjugated polymer active layer determines the electrical performance and, most importantly, the device ruggedness and lifetime. Reactive vapor coating methods allow a conjugated polymer film to be directly formed on the surface of any premade garment, prewoven fabric, or fiber/yarn substrate without the need for specialized processing conditions, surface pretreatments, detergents, or fixing agents. This feature allows electronic coatings to be applied at the end of existing, high-throughput textile and garment manufacturing routines, irrespective of dye content or surface finish of the final textile. Furthermore, reactive vapor coating produces conductive materials without any insulating moieties and yields uniform and conformal films on fiber/fabric surfaces that are notably wash- and wear-stable and can withstand mechanically demanding textile manufacturing routines. These unique features mean that rugged and practical textile electronic devices can be created using sewing, weaving, or knitting procedures without compromising or otherwise affecting the surface electronic coating. In this Account, we highlight selected electronic fabrics and garments created by melding reactive vapor deposition with traditional textile manipulation processes, including electrically heated gloves that are lightweight, breathable, and sweat-resistant; surface-coated cotton, silk, and bast fiber threads capable of carrying large current densities and acting as sewable circuit interconnects; and surface-coated nylon threads woven together to form triboelectric textiles that can convert surface charge created during small body movements into usable and storable power.

MBE HgCdTe for HDVIP Devices: Horizontal Integration in the US HgCdTe FPA Industry

NASA Astrophysics Data System (ADS)

Aqariden, F.; Elsworth, J.; Zhao, J.; Grein, C. H.; Sivananthan, S.

2012-10-01

Molecular beam epitaxy (MBE) growth of HgCdTe offers the possibility of fabricating multilayer device structures with an almost unlimited choice of infrared sensor designs for focal-plane array (FPA) fabrication. HgCdTe offers two major advantages that explain its dominance in the infrared photon detector marketplace. The thermal generation rate per unit volume of the material is lower and the quantum efficiency for photon absorption in the infrared is higher in HgCdTe than in any competing material—it yields devices with quantum efficiencies as high as 0.99. Recently, EPIR Technologies and DRS Infrared Technologies agreed to collaborate and examine: (i) the feasibility of employing MBE HgCdTe in the fabrication of high-density vertically interconnected photodiodes (HDVIPs), which are usually fabricated with liquid-phase epitaxy material, and (ii) the potential benefits of horizontal integration, with EPIR supplying the MBE materials to DRS for device and array fabrication. The team designed and developed passivation-absorber-passivation structures that are heavily used by DRS. This paper provides an overview of the characteristics of HDVIP devices and arrays fabricated from MBE HgCdTe and the anticipated advantages of horizontal integration in the industry. Material growth, device fabrication, and test results are presented.

Diamond-Based Supercapacitors: Realization and Properties.

PubMed

Gao, Fang; Nebel, Christoph E

2016-10-26

In this Spotlight on Applications, we describe our recent progress on the fabrication of surface-enlarged boron-doped polycrystalline diamond electrodes, and evaluate their performance in supercapacitor applications. We begin with a discussion of the fabrication methods of porous diamond materials. The diamond surface enlargement starts with a top-down plasma etching method. Although the extra surface area provided by surface roughening or nanostructuring provides good outcome for sensing applications, a capacitance value <1 mF cm -2 or a surface-enlargement factor <100 fail to meet the requirement of a practical supercapacitor. Driven by the need for large surface areas, we recently focused on the tempated-growth method. We worked on both supported and free-standing porous diamond materials to enhance the areal capacitance to the "mF cm -2 " range. With our newly developed free-standing diamond paper, areal capacitance can be multiplied by stacking multilayers of the electrode material. Finally, considering the fact that there is no real diamond-based supercapacitor device up to now, we fabricated the first prototype pouch-cell device based on the free-standing diamond paper to evaluate its performance. The results reveal that the diamond paper is suitable for operation in high potential windows (up to 2.5 V) in aqueous electrolyte with a capacitance of 0.688 mF cm -2 per layer of paper (or 0.645 F g -1 ). Impedance spectroscopy revealed that the operation frequency of the device exceeds 30 Hz. Because of the large potential window and the ability to work at high frequency, the specific power of the device reached 1 × 10 5 W kg -1 . In the end, we made estimations on the future target performance of diamond supercapacitors based on the existing information.

Rapid formation of size-controllable multicellular spheroids via 3D acoustic tweezers.

PubMed

Chen, Kejie; Wu, Mengxi; Guo, Feng; Li, Peng; Chan, Chung Yu; Mao, Zhangming; Li, Sixing; Ren, Liqiang; Zhang, Rui; Huang, Tony Jun

2016-07-05

The multicellular spheroid is an important 3D cell culture model for drug screening, tissue engineering, and fundamental biological research. Although several spheroid formation methods have been reported, the field still lacks high-throughput and simple fabrication methods to accelerate its adoption in drug development industry. Surface acoustic wave (SAW) based cell manipulation methods, which are known to be non-invasive, flexible, and high-throughput, have not been successfully developed for fabricating 3D cell assemblies or spheroids, due to the limited understanding on SAW-based vertical levitation. In this work, we demonstrated the capability of fabricating multicellular spheroids in the 3D acoustic tweezers platform. Our method used drag force from microstreaming to levitate cells in the vertical direction, and used radiation force from Gor'kov potential to aggregate cells in the horizontal plane. After optimizing the device geometry and input power, we demonstrated the rapid and high-throughput nature of our method by continuously fabricating more than 150 size-controllable spheroids and transferring them to Petri dishes every 30 minutes. The spheroids fabricated by our 3D acoustic tweezers can be cultured for a week with good cell viability. We further demonstrated that spheroids fabricated by this method could be used for drug testing. Unlike the 2D monolayer model, HepG2 spheroids fabricated by the 3D acoustic tweezers manifested distinct drug resistance, which matched existing reports. The 3D acoustic tweezers based method can serve as a novel bio-manufacturing tool to fabricate complex 3D cell assembles for biological research, tissue engineering, and drug development.

Thermally Conductive Metal-Tube/Carbon-Composite Joints

NASA Technical Reports Server (NTRS)

Copeland, Robert J.

2004-01-01

An improved method of fabricating joints between metal and carbon-fiber-based composite materials in lightweight radiators and heat sinks has been devised. Carbon-fiber-based composite materials have been used in such heat-transfer devices because they offer a combination of high thermal conductivity and low mass density. Metal tubes are typically used to carry heat-transfer fluids to and from such heat-transfer devices. The present fabrication method helps to ensure that the joints between the metal tubes and the composite-material parts in such heat-transfer devices have both (1) the relatively high thermal conductances needed for efficient transfer of heat and (2) the flexibility needed to accommodate differences among thermal expansions of dissimilar materials in operation over wide temperature ranges. Techniques used previously to join metal tubes with carbon-fiber-based composite parts have included press fitting and bonding with epoxy. Both of these prior techniques have been found to yield joints characterized by relatively high thermal resistances. The present method involves the use of a solder (63 percent Sn, 37 percent Pb) to form a highly thermally conductive joint between a metal tube and a carbon-fiber-based composite structure. Ordinarily, the large differences among the coefficients of thermal expansion of the metal tube, solder, and carbon-fiber-based composite would cause the solder to pull away from the composite upon post-fabrication cooldown from the molten state. In the present method, the structure of the solder is modified (see figure) to enable it to deform readily to accommodate the differential thermal expansion.

Fabrication of Continuous Microfibers Containing Magnetic Nanoparticles by a Facile Magneto-Mechanical Drawing

NASA Astrophysics Data System (ADS)

Li, Jin-Tao; Jia, Xian-Sheng; Yu, Gui-Feng; Yan, Xu; He, Xiao-Xiao; Yu, Miao; Gong, Mao-Gang; Ning, Xin; Long, Yun-Ze

2016-09-01

A facile method termed magneto-mechanical drawing is used to produce polymer composite microfibers. Compared with electrospinning and other fiber spinning methods, magneto-mechanical drawing uses magnetic force generated by a permanent magnet to draw droplets of polymer/magnetic nanoparticle suspensions, leading to fabrication of composite microfibers. In addition, because of the rotating collector, it is easy to control the fiber assembly such as fibrous array in parallel or crossed fibrous structure. The general applicability of this method has also been proved by spinning different polymers and magnetic nanoparticles. The resultant fibers exhibit good superparamagnetic behavior at room temperature and ultrahigh stretchability (~443.8 %). The results indicate that magneto-mechanical drawing is a promising technique to fabricate magnetic and stretchable microfibers and devices.

Fabrication of Continuous Microfibers Containing Magnetic Nanoparticles by a Facile Magneto-Mechanical Drawing.

PubMed

Li, Jin-Tao; Jia, Xian-Sheng; Yu, Gui-Feng; Yan, Xu; He, Xiao-Xiao; Yu, Miao; Gong, Mao-Gang; Ning, Xin; Long, Yun-Ze

2016-12-01

A facile method termed magneto-mechanical drawing is used to produce polymer composite microfibers. Compared with electrospinning and other fiber spinning methods, magneto-mechanical drawing uses magnetic force generated by a permanent magnet to draw droplets of polymer/magnetic nanoparticle suspensions, leading to fabrication of composite microfibers. In addition, because of the rotating collector, it is easy to control the fiber assembly such as fibrous array in parallel or crossed fibrous structure. The general applicability of this method has also been proved by spinning different polymers and magnetic nanoparticles. The resultant fibers exhibit good superparamagnetic behavior at room temperature and ultrahigh stretchability (~443.8 %). The results indicate that magneto-mechanical drawing is a promising technique to fabricate magnetic and stretchable microfibers and devices.

Optical waveguides in fluoride lead silicate glasses fabricated by carbon ion implantation

NASA Astrophysics Data System (ADS)

Shen, Xiao-liang; Wang, Yue; Zhu, Qi-feng; Lü, Peng; Li, Wei-nan; Liu, Chun-xiao

2018-03-01

The carbon ion implantation with energy of 4.0 MeV and a dose of 4.0×1014 ions/cm2 is employed for fabricating the optical waveguide in fluoride lead silicate glasses. The optical modes as well as the effective refractive indices are measured by the prism coupling method. The refractive index distribution in the fluoride lead silicate glass waveguide is simulated by the reflectivity calculation method (RCM). The light intensity profile and the energy losses are calculated by the finite-difference beam propagation method (FD-BPM) and the program of stopping and range of ions in matter (SRIM), respectively. The propagation properties indicate that the C2+ ion-implanted fluoride lead silicate glass waveguide is a candidate for fabricating optical devices.

Direct synthesis of vertically aligned ZnO nanowires on FTO substrates using a CVD method and the improvement of photovoltaic performance

PubMed Central

2012-01-01

In this work, we report a direct synthesis of vertically aligned ZnO nanowires on fluorine-doped tin oxide-coated substrates using the chemical vapor deposition (CVD) method. ZnO nanowires with a length of more than 30 μm were synthesized, and dye-sensitized solar cells (DSSCs) based on the as-grown nanowires were fabricated, which showed improvement of the device performance compared to those fabricated using transferred ZnO nanowires. Dependence of the cell performance on nanowire length and annealing temperature was also examined. This synthesis method provided a straightforward, one-step CVD process to grow relatively long ZnO nanowires and avoided subsequent nanowire transfer process, which simplified DSSC fabrication and improved cell performance. PMID:22673046

Perovskites-Based Solar Cells: A Review of Recent Progress, Materials and Processing Methods

PubMed Central

Shi, Zhengqi; Jayatissa, Ahalapitiya H.

2018-01-01

With the rapid increase of efficiency up to 22.1% during the past few years, hybrid organic-inorganic metal halide perovskite solar cells (PSCs) have become a research “hot spot” for many solar cell researchers. The perovskite materials show various advantages such as long carrier diffusion lengths, widely-tunable band gap with great light absorption potential. The low-cost fabrication techniques together with the high efficiency makes PSCs comparable with Si-based solar cells. But the drawbacks such as device instability, J-V hysteresis and lead toxicity reduce the further improvement and the future commercialization of PSCs. This review begins with the discussion of crystal and electronic structures of perovskite based on recent research findings. An evolution of PSCs is also analyzed with a greater detail of each component, device structures, major device fabrication methods and the performance of PSCs acquired by each method. The following part of this review is the discussion of major barriers on the pathway for the commercialization of PSCs. The effects of crystal structure, fabrication temperature, moisture, oxygen and UV towards the stability of PSCs are discussed. The stability of other components in the PSCs are also discussed. The lead toxicity and updated research progress on lead replacement are reviewed to understand the sustainability issues of PSCs. The origin of J-V hysteresis is also briefly discussed. Finally, this review provides a roadmap on the current needs and future research directions to address the main issues of PSCs. PMID:29734667

Direct single-layered fabrication of 3D concavo convex patterns in nano-stereolithography

NASA Astrophysics Data System (ADS)

Lim, T. W.; Park, S. H.; Yang, D. Y.; Kong, H. J.; Lee, K. S.

2006-09-01

A nano-surfacing process (NSP) is proposed to directly fabricate three-dimensional (3D) concavo convex-shaped microstructures such as micro-lens arrays using two-photon polymerization (TPP), a promising technique for fabricating arbitrary 3D highly functional micro-devices. In TPP, commonly utilized methods for fabricating complex 3D microstructures to date are based on a layer-by-layer accumulating technique employing two-dimensional sliced data derived from 3D computer-aided design data. As such, this approach requires much time and effort for precise fabrication. In this work, a novel single-layer exposure method is proposed in order to improve the fabricating efficiency for 3D concavo convex-shaped microstructures. In the NSP, 3D microstructures are divided into 13 sub-regions horizontally with consideration of the heights. Those sub-regions are then expressed as 13 characteristic colors, after which a multi-voxel matrix (MVM) is composed with the characteristic colors. Voxels with various heights and diameters are generated to construct 3D structures using a MVM scanning method. Some 3D concavo convex-shaped microstructures were fabricated to estimate the usefulness of the NSP, and the results show that it readily enables the fabrication of single-layered 3D microstructures.

Method for selective CMP of polysilicon

NASA Technical Reports Server (NTRS)

Babu, Suryadevara V. (Inventor); Natarajan, Anita (Inventor); Hegde, Sharath (Inventor)

2010-01-01

A method of removing polysilicon in preference to silicon dioxide and/or silicon nitride by chemical mechanical polishing. The method removes polysilicon from a surface at a high removal rate while maintaining a high selectivity of polysilicon to silicon dioxide and/or a polysilicon to silicon nitride. The method is particularly suitable for use in the fabrication of MEMS devices.

Nano-soldering of magnetically aligned three-dimensional nanowire networks.

PubMed

Gao, Fan; Gu, Zhiyong

2010-03-19

It is extremely challenging to fabricate 3D integrated nanostructures and hybrid nanoelectronic devices. In this paper, we report a simple and efficient method to simultaneously assemble and solder nanowires into ordered 3D and electrically conductive nanowire networks. Nano-solders such as tin were fabricated onto both ends of multi-segmented nanowires by a template-assisted electrodeposition method. These nanowires were then self-assembled and soldered into large-scale 3D network structures by magnetic field assisted assembly in a liquid medium with a high boiling point. The formation of junctions/interconnects between the nanowires and the scale of the assembly were dependent on the solder reflow temperature and the strength of the magnetic field. The size of the assembled nanowire networks ranged from tens of microns to millimeters. The electrical characteristics of the 3D nanowire networks were measured by regular current-voltage (I-V) measurements using a probe station with micropositioners. Nano-solders, when combined with assembling techniques, can be used to efficiently connect and join nanowires with low contact resistance, which are very well suited for sensor integration as well as nanoelectronic device fabrication.

Medium scale carbon nanotube thin film integrated circuits on flexible plastic substrates

DOEpatents

Rogers, John A; Cao, Qing; Alam, Muhammad; Pimparkar, Ninad

2015-02-03

The present invention provides device components geometries and fabrication strategies for enhancing the electronic performance of electronic devices based on thin films of randomly oriented or partially aligned semiconducting nanotubes. In certain aspects, devices and methods of the present invention incorporate a patterned layer of randomly oriented or partially aligned carbon nanotubes, such as one or more interconnected SWNT networks, providing a semiconductor channel exhibiting improved electronic properties relative to conventional nanotubes-based electronic systems.

Rapid Stencil Mask Fabrication Enabled One-Step Polymer-Free Graphene Patterning and Direct Transfer for Flexible Graphene Devices

PubMed Central

Yong, Keong; Ashraf, Ali; Kang, Pilgyu; Nam, SungWoo

2016-01-01

We report a one-step polymer-free approach to patterning graphene using a stencil mask and oxygen plasma reactive-ion etching, with a subsequent polymer-free direct transfer for flexible graphene devices. Our stencil mask is fabricated via a subtractive, laser cutting manufacturing technique, followed by lamination of stencil mask onto graphene grown on Cu foil for patterning. Subsequently, micro-sized graphene features of various shapes are patterned via reactive-ion etching. The integrity of our graphene after patterning is confirmed by Raman spectroscopy. We further demonstrate the rapid prototyping capability of a stretchable, crumpled graphene strain sensor and patterned graphene condensation channels for potential applications in sensing and heat transfer, respectively. We further demonstrate that the polymer-free approach for both patterning and transfer to flexible substrates allows the realization of cleaner graphene features as confirmed by water contact angle measurements. We believe that our new method promotes rapid, facile fabrication of cleaner graphene devices, and can be extended to other two dimensional materials in the future. PMID:27118249

Graphene/Si CMOS Hybrid Hall Integrated Circuits

PubMed Central

Huang, Le; Xu, Huilong; Zhang, Zhiyong; Chen, Chengying; Jiang, Jianhua; Ma, Xiaomeng; Chen, Bingyan; Li, Zishen; Zhong, Hua; Peng, Lian-Mao

2014-01-01

Graphene/silicon CMOS hybrid integrated circuits (ICs) should provide powerful functions which combines the ultra-high carrier mobility of graphene and the sophisticated functions of silicon CMOS ICs. But it is difficult to integrate these two kinds of heterogeneous devices on a single chip. In this work a low temperature process is developed for integrating graphene devices onto silicon CMOS ICs for the first time, and a high performance graphene/CMOS hybrid Hall IC is demonstrated. Signal amplifying/process ICs are manufactured via commercial 0.18 um silicon CMOS technology, and graphene Hall elements (GHEs) are fabricated on top of the passivation layer of the CMOS chip via a low-temperature micro-fabrication process. The sensitivity of the GHE on CMOS chip is further improved by integrating the GHE with the CMOS amplifier on the Si chip. This work not only paves the way to fabricate graphene/Si CMOS Hall ICs with much higher performance than that of conventional Hall ICs, but also provides a general method for scalable integration of graphene devices with silicon CMOS ICs via a low-temperature process. PMID:24998222

Graphene/Si CMOS hybrid hall integrated circuits.

PubMed

Huang, Le; Xu, Huilong; Zhang, Zhiyong; Chen, Chengying; Jiang, Jianhua; Ma, Xiaomeng; Chen, Bingyan; Li, Zishen; Zhong, Hua; Peng, Lian-Mao

2014-07-07

Graphene/silicon CMOS hybrid integrated circuits (ICs) should provide powerful functions which combines the ultra-high carrier mobility of graphene and the sophisticated functions of silicon CMOS ICs. But it is difficult to integrate these two kinds of heterogeneous devices on a single chip. In this work a low temperature process is developed for integrating graphene devices onto silicon CMOS ICs for the first time, and a high performance graphene/CMOS hybrid Hall IC is demonstrated. Signal amplifying/process ICs are manufactured via commercial 0.18 um silicon CMOS technology, and graphene Hall elements (GHEs) are fabricated on top of the passivation layer of the CMOS chip via a low-temperature micro-fabrication process. The sensitivity of the GHE on CMOS chip is further improved by integrating the GHE with the CMOS amplifier on the Si chip. This work not only paves the way to fabricate graphene/Si CMOS Hall ICs with much higher performance than that of conventional Hall ICs, but also provides a general method for scalable integration of graphene devices with silicon CMOS ICs via a low-temperature process.

Characterization of bonding between poly(dimethylsiloxane) and cyclic olefin copolymer using corona discharge induced grafting polymerization.

PubMed

Liu, Ke; Gu, Pan; Hamaker, Kiri; Fan, Z Hugh

2012-01-01

Thermoplastics have been increasingly used for fabricating microfluidic devices because of their low cost, mechanical/biocompatible attributes, and well-established manufacturing processes. However, there is sometimes a need to integrate such a device with components made from other materials such as polydimethylsiloxane (PDMS). Bonding thermoplastics with PDMS to produce hybrid devices is not straightforward. We have reported our method to modify the surface property of a cyclic olefin copolymer (COC) substrate by using corona discharge and grafting polymerization of 3-(trimethoxysilyl)propyl methacrylate; the modified surface enabled strong bonding of COC with PDMS. In this paper, we report our studies on the surface modification mechanism using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and contact angle measurement. Using this bonding method, we fabricated a three-layer (COC/PDMS/COC) hybrid device consisting of elastomer-based valve arrays. The microvalve operation was confirmed through the displacement of a dye solution in a fluidic channel when the elastomer membrane was pneumatically actuated. Valve-enabled microfluidic handling was demonstrated. Copyright © 2011 Elsevier Inc. All rights reserved.

Fabrication of zein nanostructure

NASA Astrophysics Data System (ADS)

Luecha, Jarupat

The concerns on the increase of polluting plastic wastes as well as the U.S. dependence on imported petrochemical products have driven an attention towards alternative biodegradable polymers from renewable resources. Zein protein, a co-product from ethanol production from corn, is a good candidate. This research project aims to increase zein value by adopting nanotechnology for fabricating advanced zein packaging films and zein microfluidic devices. Two nanotechnology approaches were focused: the polymer nanoclay nanocomposite technique where the nanocomposite structures were created in the zein matrix, and the soft lithography and the microfluidic devices where the micro and nanopatterns were created on the zein film surfaces. The polymer nanoclay nanocomposite technique was adopted in the commonly used zein film fabrication processes which were solvent casting and extrusion blowing methods. The two methods resulted in partially exfoliated nanocomposite structures. The impact of nanoclays on the physical properties of zein films strongly depended on the film preparation techniques. The impact of nanoclay concentration was more pronounced in the films made by extrusion blowing technique than by the solvent casting technique. As the processability limitation for the extrusion blowing technique of the zein sample containing hight nanoclay content, the effect of the nanoclay content on the rheological properties of zein hybrid resins at linear and nonlinear viscoelastic regions were further investigated. A pristine zein resin exhibited soft solid like behavior. On the other hand, the zein hybrid with nanoclay content greater than 5 wt.% showed more liquid like behavior, suggesting that the nanoclays interrupted the entangled zein network. There was good correspondence between the experimental data and the predictions of the Wagner model for the pristine zein resins. However, the model failed to predict the steady shear properties of the zein nanoclay nanocomposite resins. The soft lithography technique was mainly used to fabricate micro and nanostructures on zein films. Zein material well-replicated small structures with the smallest size at sub micrometer scale that resulted in interesting photonic properties. The bonding method was also developed for assembling portable zein microfluidic devices with small shape distortion. Zein-zein and zein-glass microfluidic devices demonstrated sufficient strength to facilitate fluid flow in a complex microfluidic design with no leakage. Aside from the fabrication technique development, several potential applications of this environmentally friendly microfluidic device were investigated. The concentration gradient manipulation of Rhodamine B solution in zein-glass microfluidic devices was demonstrated. The diffusion of small molecules such as fluorescent dye into the wall of the zein microfluidic channels was observed. However, with this formulation, zein microfluidic devices were not suitable for cell culture applications. This pioneer study covered a wide spectrum of the implementation of the two nanotechnology approaches to advance zein biomaterial which provided proof of fundamental concepts as well as presenting some limitations. The findings in this study can lead to several innovative research opportunities of advanced zein biomaterials with broad applications. The information from the study of zein nanocomposite structure allows the packaging industry to develop the low cost biodegradable materials with physical property improvement. The information from the study of the zein microfluidic devices allows agro-industry to develop the nanotechnology-enabled microfluidic sensors fabricated entirely from biodegradable polymer for on-site disease or contaminant detection in the fields of food and agriculture.

Embedded high-contrast distributed grating structures

DOEpatents

Zubrzycki, Walter J.; Vawter, Gregory A.; Allerman, Andrew A.

2002-01-01

A new class of fabrication methods for embedded distributed grating structures is claimed, together with optical devices which include such structures. These new methods are the only known approach to making defect-free high-dielectric contrast grating structures, which are smaller and more efficient than are conventional grating structures.

Josephson junction

DOEpatents

Wendt, J.R.; Plut, T.A.; Martens, J.S.

1995-05-02

A novel method for fabricating nanometer geometry electronic devices is described. Such Josephson junctions can be accurately and reproducibly manufactured employing photolithographic and direct write electron beam lithography techniques in combination with aqueous etchants. In particular, a method is described for manufacturing planar Josephson junctions from high temperature superconducting material. 10 figs.

Development of termination and utilization concepts for flat conductor cables. Volume 1: Development of low profile flat conductor cable connecting device and permanent splice

NASA Technical Reports Server (NTRS)

1972-01-01

The development of low-profile flat conductor cable (FCC) connecting device and FCC permanent splice methods are discussed. The design goal for the low-profile connecting device was to mate and unmate FCC harness to a typical spacecraft component with a maximum height of 3/8 in. The results indicate that the design, fabrication, and processing of the low-profile connecting device are feasible and practical. Some redesign will be required to achieve the goal of 3/8 in. Also, failures were experienced subsequent to salt spray and humidity exposure. Five different FCC permanent splice methods were considered. Subsequent to evaluation of these five methods, two design concepts were chosen for development tests.

Progress in performance enhancement methods for capacitive silicon resonators

NASA Astrophysics Data System (ADS)

Van Toan, Nguyen; Ono, Takahito

2017-11-01

In this paper, we review the progress in recent studies on the performance enhancement methods for capacitive silicon resonators. We provide information on various fabrication technologies and design considerations that can be employed to improve the performance of capacitive silicon resonators, including low motional resistance, small insertion loss, and high quality factor (Q). This paper contains an overview of device structures and working principles, fabrication technologies consisting of hermetic packaging, deep reactive-ion etching and neutral beam etching, and design considerations including mechanically coupled, movable electrode structures and piezoresistive heat engines.

A Novel Internal Fixator Device for Peripheral Nerve Regeneration

PubMed Central

Chuang, Ting-Hsien; Wilson, Robin E.; Love, James M.; Fisher, John P.

2013-01-01

Recovery from peripheral nerve damage, especially for a transected nerve, is rarely complete, resulting in impaired motor function, sensory loss, and chronic pain with inappropriate autonomic responses that seriously impair quality of life. In consequence, strategies for enhancing peripheral nerve repair are of high clinical importance. Tension is a key determinant of neuronal growth and function. In vitro and in vivo experiments have shown that moderate levels of imposed tension (strain) can encourage axonal outgrowth; however, few strategies of peripheral nerve repair emphasize the mechanical environment of the injured nerve. Toward the development of more effective nerve regeneration strategies, we demonstrate the design, fabrication, and implementation of a novel, modular nerve-lengthening device, which allows the imposition of moderate tensile loads in parallel with existing scaffold-based tissue engineering strategies for nerve repair. This concept would enable nerve regeneration in two superposed regimes of nerve extension—traditional extension through axonal outgrowth into a scaffold and extension in intact regions of the proximal nerve, such as that occurring during growth or limb-lengthening. Self-sizing silicone nerve cuffs were fabricated to grip nerve stumps without slippage, and nerves were deformed by actuating a telescoping internal fixator. Poly(lactic co-glycolic) acid (PLGA) constructs mounted on the telescoping rods were apposed to the nerve stumps to guide axonal outgrowth. Neuronal cells were exposed to PLGA using direct contact and extract methods, and they exhibited no signs of cytotoxic effects in terms of cell morphology and viability. We confirmed the feasibility of implanting and actuating our device within a sciatic nerve gap and observed axonal outgrowth following device implantation. The successful fabrication and implementation of our device provides a novel method for examining mechanical influences on nerve regeneration. PMID:23102114

Fabrication of poly(methyl methacrylate)-MoS{sub 2}/graphene heterostructure for memory device application

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

Shinde, Sachin M.; Tanemura, Masaki; Kalita, Golap, E-mail: kalita.golap@nitech.ac.jp

2014-12-07

Combination of two dimensional graphene and semi-conducting molybdenum disulfide (MoS{sub 2}) is of great interest for various electronic device applications. Here, we demonstrate fabrication of a hybridized structure with the chemical vapor deposited graphene and MoS{sub 2} crystals to configure a memory device. Elongated hexagonal and rhombus shaped MoS{sub 2} crystals are synthesized by sulfurization of thermally evaporated molybdenum oxide (MoO{sub 3}) thin film. Scanning transmission electron microscope studies reveal atomic level structure of the synthesized high quality MoS{sub 2} crystals. In the prospect of a memory device fabrication, poly(methyl methacrylate) (PMMA) is used as an insulating dielectric material asmore » well as a supporting layer to transfer the MoS{sub 2} crystals. In the fabricated device, PMMA-MoS{sub 2} and graphene layers act as the functional and electrode materials, respectively. Distinctive bistable electrical switching and nonvolatile rewritable memory effect is observed in the fabricated PMMA-MoS{sub 2}/graphene heterostructure. The developed material system and demonstrated memory device fabrication can be significant for next generation data storage applications.« less

Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system

DOEpatents

Charache, Greg W.; Baldasaro, Paul F.; Nichols, Greg J.

1998-01-01

A thermophotovoltaic energy conversion device and a method for making the device. The device includes a substrate formed from a bulk single crystal material having a bandgap (E.sub.g) of 0.4 eV

Microfluidic device for chemical and mechanical manipulation of suspended cells

NASA Astrophysics Data System (ADS)

Rezvani, Samaneh; Shi, Nan; Squires, Todd M.; Schmidt, Christoph F.

2018-01-01

Microfluidic devices have proven to be useful and versatile for cell studies. We here report on a method to adapt microfluidic stickers made from UV-curable optical adhesive with inserted permeable hydrogel membrane micro-windows for mechanical studies of suspended cells. The windows were fabricated by optical projection lithography using scanning confocal microscopy. The device allows us to rapidly exchange embedding medium while observing and probing the cells. We characterize the device and demonstrate the function by exposing cultured fibroblasts to varying osmotic conditions. Cells can be shrunk reversibly under osmotic compression.

Self-aligned gated field emission devices using single carbon nanofiber cathodes

NASA Astrophysics Data System (ADS)

Guillorn, M. A.; Melechko, A. V.; Merkulov, V. I.; Hensley, D. K.; Simpson, M. L.; Lowndes, D. H.

2002-11-01

We report on the fabrication and operation of integrated gated field emission devices using single vertically aligned carbon nanofiber (VACNF) cathodes where the gate aperture has been formed using a self-aligned technique based on chemical mechanical polishing. We find that this method for producing gated cathode devices easily achieves structures with gate apertures on the order of 2 mum that show good concentric alignment to the VACNF emitter. The operation of these devices was explored and field emission characteristics that fit well to the Fowler-Nordheim model of emission was demonstrated.

Composite patterning devices for soft lithography

DOEpatents

Rogers, John A.; Menard, Etienne

2007-03-27

The present invention provides methods, devices and device components for fabricating patterns on substrate surfaces, particularly patterns comprising structures having microsized and/or nanosized features of selected lengths in one, two or three dimensions. The present invention provides composite patterning devices comprising a plurality of polymer layers each having selected mechanical properties, such as Young's Modulus and flexural rigidity, selected physical dimensions, such as thickness, surface area and relief pattern dimensions, and selected thermal properties, such as coefficients of thermal expansion, to provide high resolution patterning on a variety of substrate surfaces and surface morphologies.