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Sample records for noncontacting electromechanical devices

  1. A new approach to long-life noncontacting electromechanical devices. [for space flight applications

    NASA Technical Reports Server (NTRS)

    Devine, E. J.

    1973-01-01

    Brushless dc motors are finding increasing application in space. Likewise, with the advent of the light emitting diode, noncontacting encoders are gradually replacing sliding contact types. The direct drive concept has proved its merit and is now the preferred approach for tape recorders and low to moderate torque instrument drives. The final step in this evolution is the magnetic bearing, which now appears feasible for several applications. Where it can be applied in a totally noncontacting system, life and reliability will be a function of the electronic controls, where redundancy, derating, and quality assurance approaches virtually assure the desired lifetime and failure rate.

  2. Magnetic field control. [electromechanical torquing device

    NASA Technical Reports Server (NTRS)

    Haeussermann, W. (Inventor)

    1982-01-01

    A torque control for an electromechanical torquing device of a type where a variable clearance occurs between a rotor and field is described. A Hall effect device senses the field present, which would vary as a function of spacing between field and rotor. The output of the Hall effect device controls the power applied to the field so as to provide a well defined field and thus a controlled torque to the rotor which is well defined.

  3. Handheld-Level Electromechanical Cartilage Reshaping Device.

    PubMed

    Kim, Sehwan; Manuel, Cyrus T; Wong, Brian J F; Chung, Phil-Sang; Mo, Ji-Hun

    2015-06-01

    We have developed a handheld-level multichannel electromechanical reshaping (EMR) cartilage device and evaluated the feasibility of providing a means of cartilage reshaping in a clinical outpatient setting. The effect of EMR on pig costal cartilage was evaluated in terms of shape change, tissue heat generation, and cell viability. The pig costal cartilage specimens (23 mm × 6.0 mm × 0.7 mm) were mechanically deformed to 90 degrees and fixed to a plastic jig and applied 5, 6, 7, and 8 V up to 8 minutes to find the optimal dosimetry for the our developed EMR device. The results reveal that bend angle increased with increasing voltage and application time. The maximum bend angle obtained was 70.5 ± 7.3 at 8 V, 5 minutes. The temperature of flat pig costal cartilage specimens were measured, while a constant electric voltage was applied to three pairs of electrodes that were inserted into the cartilages. The nonthermal feature of EMR was validated by a thermal infrared camera; that is, the maximum temperate of the flat cartilages is 20.3°C at 8 V. Cell viability assay showed no significant difference in cell damaged area from 3 to 7 minutes exposure with 7 V. In conclusion, the multichannel EMR device that was developed showed a good feasibility of cartilage shaping with minimal temperature change. PMID:26126226

  4. A triple quantum dot based nano-electromechanical memory device

    SciTech Connect

    Pozner, R.; Lifshitz, E.; Peskin, U.

    2015-09-14

    Colloidal quantum dots (CQDs) are free-standing nano-structures with chemically tunable electronic properties. This tunability offers intriguing possibilities for nano-electromechanical devices. In this work, we consider a nano-electromechanical nonvolatile memory (NVM) device incorporating a triple quantum dot (TQD) cluster. The device operation is based on a bias induced motion of a floating quantum dot (FQD) located between two bound quantum dots (BQDs). The mechanical motion is used for switching between two stable states, “ON” and “OFF” states, where ligand-mediated effective interdot forces between the BQDs and the FQD serve to hold the FQD in each stable position under zero bias. Considering realistic microscopic parameters, our quantum-classical theoretical treatment of the TQD reveals the characteristics of the NVM.

  5. Electromechanical delay of the hamstrings during eccentric muscle actions in males and females: Implications for non-contact ACL injuries.

    PubMed

    De Ste Croix, Mark B A; ElNagar, Youssif O; Iga, John; James, David; Ayala, Francisco

    2015-12-01

    Sex differences in neuromuscular functioning has been proposed as one of the factors behind an increased relative risk of non-contact anterior cruciate ligament (ACL) injury in females. The aim of this study was to explore sex differences in electromechanical delay (EMD) of the hamstring muscles during eccentric muscle actions and during a range of movement velocities. This study recruited 110 participants (55 males, 55 females) and electromyography of the semitendinosus, semimembranosus and biceps femoris was determined during eccentric actions at 60, 120 and 240°/s. No significant sex differences were observed irrespective of muscle examined or movement velocity. Irrespective of sex EMD significantly increased with increasing movement velocity (P < 0.01). There was no significant difference in the EMD of the 3 muscles examined. Our findings suggest that during eccentric actions of the hamstrings that there are no sex differences, irrespective of movement velocity. This would suggest that other factors are probably responsible for the increased relative risk of non-contact ACL injury in females compared to males. PMID:26522999

  6. 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

  7. Atomistic and model description of nanotube electromechanical devices

    NASA Astrophysics Data System (ADS)

    Rotkin, Slava V.

    2003-03-01

    Nanotubes (NTs), which are natural objects on the size scale compatible with nanodevices and bio-molecules, exhibit several unique properties by themselves and in specific environments such as electronic, bio-chemical or electromechanical nanodevices. A compact continuum model has been developed [1] for the multi-scale calculation of NT behavior in various devices, ranging from Nano-Electromechanical Systems (NEMS)[2] to Light-Controlled Molecular Switches [3]. The continuum model parameterization is based on Molecular Dynamics and microscopic modeling. For example, elements of quantum mechanical consideration were introduced through the calculation of the nanotube polarizability, atomistic capacitance [4], and van der Waals interaction [5]. Quantum-chemistry approach was used for computation of an equilibrium structure of chemically modified NTs. An analytical expression will be discussed for quantum capacitance of metallic NTs with arbitrary lateral deformation. Compact model and a quantum mechanical simulation will be compared for the NT charge density calculation. A scattering probability for a potential of charged impurity and ballistic conductance of NT channel have been computed for a light controlled electronic NT switch. Analytical expression for the pull-in voltage for NT NEMS will be presented with quantum corrections and van der Waals interactions taken into account. This calculation will demonstrate that a principal physical limit exists for fabricating NEMS [6]. 1. N.R.Aluru, et.al., in Handbook of Nanoscience, Engineering and Technology, Eds: W.Goddard, et.al.; CRC Press, 2002 2. M.Dequesnes, S.V.Rotkin, N.R.Aluru, Nanotechnology 13, 2002 3. S.V.Rotkin, I.Zharov, Int.J.of Nanoscience 1(3/4) 2002 4. K.A.Bulashevich, S.V.Rotkin, JETPL 75(4) 2002 5. S.V.Rotkin, K.Hess, J.of Comp.Electronics 1(3) 2002 6. S.V.Rotkin, in Microfabr. Syst. and MEMS, Eds: P. J. Hesketh, et.al. ECS Inc., Pennington, NJ, USA 2002

  8. Non-contact type seal device for turbocharger

    SciTech Connect

    Washimi, K.; Shibata, M.; Ugajin, M.

    1987-02-24

    A non-contact type seal device is described for a turbocharger, comprising: a retainer mounted in a compressor chamber of a housing of the turbocharger; a collar attached to a compressor wheel mounting portion of a rotor shaft of the turbocharger; and a ring provided on an inner peripheral surface of the retainer, an annular groove receiving the ring being formed in an outer peripheral surface of the collar; a first gap being formed between the outer peripheral surface of the collar and the inner peripheral surface of the retainer; a second gap being formed between the inner surface of the annular groove and each of inner and opposite end surfaces of the ring; and a threaded groove being formed in the inner peripheral surface of the retainer in opposition to the outer peripheral surface of the collar.

  9. Flow visualization of a non-contact transport device by Coanda effect

    NASA Astrophysics Data System (ADS)

    Iki, Norihiko; Abe, Hiroyuki; Okada, Takashi

    2014-08-01

    AIST proposes new technology of non-contact transport device utilizing Coanda effect. A proposed non-contact transport device has a cylindrical body and circular slit for air. The air flow around non-contact device is turbulent and its flow pattern depends on the injection condition. Therefore we tried visualization of the air flow around non -contact device as the first step of PIV measurement. Several tracer particles were tried such as TiO2 particles, water droplets, potatoes starch, rice starch, corn starch. Hot-wire anemometer is employed to velocity measurement. TiO2 particles deposit inside of a slit and clogging of a slit occurs frequently. Potato starch particles do not clog a slit but they are too heavy to trace slow flow area. Water droplets by ultrasonic atomization also deposit inside of slit but they are useful to visualize flow pattern around a non-contact transport device by being supplied from circumference. Coanda effect of proposed non-contact transport device was confirmed and injected air flow pattern switches by a work. Air flow around non-contact trance port device is turbulent and its velocity range is wide. Therefore flow measurement by tracer part icle has traceability issue. Suitable tracer and exposure condition depends on target area.

  10. Noncontacting measuring device to indicate deflection of turbopump internal rotating parts

    NASA Technical Reports Server (NTRS)

    Hamilton, D. B.; Grieser, D. R.; Plummer, A. M.; Ensminger, D.; Saccacio, E. J.; Kissel, J. W.

    1971-01-01

    Noncontacting, nondestructive techniques to measure vibrations and deflections of parts in future LOX and LH2 multistage turbopump prototypes are reported. The measurements include shaft vibration, vibration of turbine wheel and blades, blade clearance, vibration of impellers, value component flutter, and vibration of face seal components. Three techniques were selected for development: ultrasonic Doppler devices, flash X-ray, and light-pipe reflectance.

  11. [Development of Non-Contact Monitoring Device for Breathing and Heartbeat].

    PubMed

    Hu, Ye; Li, Chuantao; Qi, Fugui; Wang, Shuaijie; Zhang, Hua; Wang, Jianqi; Lu, Guohua

    2015-07-01

    Physiological monitoring devices in modern clinical area are basically used electrodes or sensors directly touching the surface of human subject body, which will increase physiological and psychological load of the subjects. In order to realize non-contact monitoring of respiration and heartbeat, firstly, the micro bioradar was used to detect human body motion signal. Then, the respiration signal and heartbeat signal was extracted from the body-motion signal by using signal and conditioning circuits, digital filter and signal processing. Finally, the results of heart rate and breathing rate was wirelessly transmitted. The experimental results showed that the device for non-contact monitoring of respiration and heartbeat waveforms has advantages of small volume, low power consumption, which can realize the monitoring of physiological parameters in real time.

  12. A bendable and wearable cardiorespiratory monitoring device fusing two noncontact sensor principles.

    PubMed

    Teichmann, Daniel; De Matteis, Dennis; Bartelt, Thorsten; Walter, Marian; Leonhardt, Steffen

    2015-05-01

    A mobile device is presented for monitoring both respiration and pulse. The device is developed as a bendable/flexible inlay that can be placed in a shirt pocket or the inside pocket of a jacket. To achieve optimum monitoring performance, the device combines two sensor principles, which work in a safe noncontact way through several layers of cotton or other textiles. One sensor, based on magnetic induction, is intended for respiratory monitoring, and the other is a reflective photoplethysmography sensor intended for pulse detection. Because each sensor signal has some dependence on both physiological parameters, fusing the sensor signals allows enhanced signal coverage.

  13. Issues on utility management simulation system for miscellaneous airborne electromechanical devices

    NASA Astrophysics Data System (ADS)

    Chen, Juan; Liu, Qiaozhen; Wang, Zhanlin

    2006-11-01

    UMS for miscellaneous airborne electromechanical devices is the part and parcel of VMS. The object of utility management is airborne electromechanical devices which ensure that air engine, avionics and other systems work in order. This paper works over several items about UMS by introducing advanced simulation and its correlative technologies. Firstly, message transmission software of 1553B bus is designed and the bus characteristics are tested. Also, the problem of time synchronization is solved by testing network delay. Secondly, in order to obtain high performance of distributed process ability, heuristic job dispatching algorithm and hydrodynamic load balancing strategy are adopted, which solve the static job dispatch and dynamic job scheduling respectively. The hydrodynamic load balancing strategy is aiming to fulfill the resources usage in the whole system and accomplishes best resources sharing. Thirdly, this paper establishes and realizes the demo environment for visual simulation of the electromechanical subsystems. Adopting tree-mode during the software design makes the system scalable and reconstruction. As multithreading synchronization is resolved, real-time performance of simulation. is ensured during.

  14. Non-Contact Stiffness Measurement of a Suspended Single Walled Carbon Nanotube Device

    NASA Technical Reports Server (NTRS)

    Zheng, Yun; Su, Chanmin; Getty, Stephanie

    2010-01-01

    A new nanoscale electric field sensor was developed for studying triboelectric charging in terrestrial and Martian dust devils. This sensor is capable to measure the large electric fields for large dust devils without saturation. However, to quantify the electric charges and the field strength it is critical to calibrate the mechanical stiffness of the sensor devices. We performed a technical feasibility study of the Nano E-field Sensor stiffness by a non-contact stiffness measurement method. The measurement is based on laser Doppler vibrometer measurement of the thermal noise due to energy flunctuations in the devices. The experiment method provides a novel approach to acquire data that is essential in analyzing the quantitative performance of the E-field Nano Sensor. To carry out the non-contact stiffness measurement, we fabricated a new Single-Walled Carbon Nanotube (SWCNT) E-field sensor with different SWCNTs suspension conditions. The power spectra of the thermal induced displacement in the nano E-field sensor were measured at the accuracy of picometer. The power spectra were then used to derive the mechanical stiffness of the sensors. Effect of suspension conditions on stiffness and sensor sensitivty was discussed. After combined deformation and resistivity measurement, we can compare with our laboratory testing and field testing results. This new non-contact measurement technology can also help to explore to other nano and MEMS devices in the future.

  15. Noncontact rack-pinion-rack device as a differential vibration sensor.

    PubMed

    Miri, MirFaez; Nasiri, Mojtaba

    2010-07-01

    We study a nanoscale system composed of one corrugated cylinder (pinion) placed between two corrugated plates (racks). The pinion and racks have no mechanical contact, but are coupled via the lateral Casimir force-one of the most spectacular consequences of quantum fluctuations of the electromagnetic field. The noncontact design of the device could help with the noteworthy wear problem in nanoscale mechanical systems. We consider the case where both racks undergo harmonic lateral motion. We assume that the amplitude, frequency, and phase of one of the racks are known. We show that probing the pinion motion, one can determine the vibration characteristics of the other rack.

  16. Comparison of contact and non-contact asphere surface metrology devices

    NASA Astrophysics Data System (ADS)

    DeFisher, Scott; Fess, Edward M.

    2013-09-01

    Metrology of asphere surfaces is critical in the precision optics industry. Surface metrology serves as feedback into deterministic grinding and polishing platforms. Many different techniques and devices are used to qualify an asphere surface during fabrication. A contact profilometer is one of the most common measurement technologies used in asphere manufacturing. A profilometer uses a fine stylus to drag a diamond or ruby tip over the surface, resulting in a high resolution curved profile. Coordinate measuring machines (CMM) apply a similar concept by touching the optic with a ruby or silicon carbine sphere. A CMM is able to move in three dimensions while collecting data points along the asphere surface. Optical interferometers use a helium-neon laser with transmission spheres to compare a reflected wavefront from an asphere surface to a reference spherical wavefront. Large departure aspheres can be measured when a computer generated hologram (CGH) is introduced between the interferometer and the optic. OptiPro Systems has developed a non-contact CMM called UltraSurf. It utilizes a single point non-contact sensor, and high accuracy air bearings. Several different commercial non-contact sensors have been integrated, allowing for the flexibility to measure a variety of surfaces and materials. Metrology of a sphere and an asphere using a profilometer, CMM, Interferometer with a CGH, and the UltraSurf will be presented. Cross-correlation of the measured surface error magnitude and shape will be demonstrated. Comparisons between the techniques and devices will be also presented with attention to accuracy, repeatability, and overall measurement time.

  17. Laser desorption of explosives as a way to create an effective non-contact sampling device

    NASA Astrophysics Data System (ADS)

    Akmalov, Artem E.; Chistyakov, Alexander A.; Kotkovskii, Gennadii E.

    2015-10-01

    Comparison of desorption effectiveness of Nd3+:YAG nanosecond laser sources (λ=266, 354, 532 nm) has been carried out to investigate a possibility of creating a non-contact sampling device for detectors of explosives based on principles of ion mobility spectrometry (IMS) and field asymmetric ion mobility spectrometry (FAIMS). The results of mass spectrometric study of laser desorption of nitroamine, nitrate ester and nitroaromatic compounds from a quartz substrate are presented. It is shown that irradiation of adsorbed layers of studied samples by a single pulse of non-resonant laser radiation (λ=532 nm) leads to efficient desorption at laser intensity 107 W/cm2 and above. Excitation of the first singlet state of nitro compounds by resonant radiation (λ=354 nm) provides heating of adsorbed layers and thermal desorption. A strongly non-equilibrium (non-thermal) dissociation process is developed when the second singlet state of nitroaromatic molecules is excited by radiation at λ=266 nm, along with thermal desorption. It is shown that Nd3+: YAG laser with wavelength λ=266 nm, pulse duration 5-10 ns, intensity 107-109 W/cm2 is the most effective source for creation a non-contact sampling device based on desorption of explosives from surfaces.

  18. A Combined Structural and Electromechanical FE Approach for Industrial Ultrasonic Devices Design

    NASA Astrophysics Data System (ADS)

    Schorderet, Alain; Prenleloup, Alain; Colla, Enrico

    2011-05-01

    Ultrasonic assistance is widely used in manufacturing, both for conventional (e.g. grinding, drilling) and non-conventional (e.g. EDM) processes. Ultrasonic machining is also used as a stand alone process for instance for micro-drilling. Industrial application of these processes requires increasingly efficient and accurate development tools to predict the performance of the ultrasonic device: the so-called sonotrode and the piezo-transducer. This electromechanical system consists of a structural part and of a piezo-electrical part (actuator). In this paper, we show how to combine two simulation softwares—for stuctures and electromechanical devices—to perform a complete design analysis and optimization of a sonotrode for ultrasonic drilling applications. The usual design criteria are the eigenfrequencies of the desired vibrational modes. In addition, during the optimization phase, one also needs to consider the maximum achievable displacement for a given applied voltage. Therefore, one must be able to predict the electromechanical behavior of the integrated piezo-structure system, in order to define, adapt and optimize the electric power supply as well as the control strategy (search, tracking of the eigenfrequency). In this procedure, numerical modelling follows a two-step approach, by means of a solid mechanics FE code (ABAQUS) and of an electromechanical simulation software (ATILA). The example presented illustrates the approach and describes the obtained results for the development of an industrial sonotrode system dedicated to ultrasonic micro-drilling of ceramics. The 3D model of the sonotrode serves as input for generating the FE mesh in ABAQUS and this mesh is then translated into an input file for ATILA. ABAQUS results are used to perform the first optimization step in order to obtain a sonotrode design leading to the requested modal behaviour—eigen-frequency and corresponding dynamic amplification. The second step aims at evaluating the dynamic

  19. System and method of active vibration control for an electro-mechanically cooled device

    DOEpatents

    Lavietes, Anthony D.; Mauger, Joseph; Anderson, Eric H.

    2000-01-01

    A system and method of active vibration control of an electro-mechanically cooled device is disclosed. A cryogenic cooling system is located within an environment. The cooling system is characterized by a vibration transfer function, which requires vibration transfer function coefficients. A vibration controller generates the vibration transfer function coefficients in response to various triggering events. The environments may differ by mounting apparatus, by proximity to vibration generating devices, or by temperature. The triggering event may be powering on the cooling system, reaching an operating temperature, or a reset action. A counterbalance responds to a drive signal generated by the vibration controller, based on the vibration signal and the vibration transfer function, which adjusts vibrations. The method first places a cryogenic cooling system within a first environment and then generates a first set of vibration transfer function coefficients, for a vibration transfer function of the cooling system. Next, the cryogenic cooling system is placed within a second environment and a second set of vibration transfer function coefficients are generated. Then, a counterbalance is driven, based on the vibration transfer function, to reduce vibrations received by a vibration sensitive element.

  20. Superconducting electromechanical rotating device having a liquid-cooled, potted, one layer stator winding

    DOEpatents

    Dombrovski, Viatcheslav V.; Driscoll, David I.; Shovkhet, Boris A.

    2001-01-01

    A superconducting electromechanical rotating (SER) device, such as a synchronous AC motor, includes a superconducting field winding and a one-layer stator winding that may be water-cooled. The stator winding is potted to a support such as the inner radial surface of a support structure and, accordingly, lacks hangers or other mechanical fasteners that otherwise would complicate stator assembly and require the provision of an unnecessarily large gap between adjacent stator coil sections. The one-layer winding topology, resulting in the number of coils being equal to half the number of slots or other mounting locations on the support structure, allows one to minimize or eliminate the gap between the inner radial ends of adjacent straight sections of the stator coilswhile maintaining the gap between the coil knuckles equal to at least the coil width, providing sufficient room for electrical and cooling element configurations and connections. The stator winding may be potted to the support structure or other support, for example, by a one-step VPI process relying on saturation of an absorbent material to fill large gaps in the stator winding or by a two-step process in which small gaps are first filled via a VPI or similar operation and larger gaps are then filled via an operation that utilizes the stator as a portion of an on-site mold.

  1. Electromechanical response of single-walled carbon nanotubes to torsional strain in a self-contained device.

    PubMed

    Hall, Adam R; Falvo, Michael R; Superfine, Richard; Washburn, Sean

    2007-07-01

    Nanoscale electronics seeks to decrease the critical dimension of devices in order to improve performance while reducing power consumption. Single-walled carbon nanotubes fit well with this strategy because, in addition to their molecular size, they demonstrate a number of unique electronic, mechanical and electromechanical properties. In particular, theory predicts that strain can have a large effect on the band structure of a nanotube, which, in turn, has an influence on its electron transport properties. This has been demonstrated in experiments where axial strain was applied by a scanning probe. Theory also predicts that torsional strain can influence transport properties, which was observed recently in multiwalled nanotubes. Here we present the first experimental evidence of an electromechanical effect from torsional strain in single-walled nanotubes, and also the first measurements of piezoresistive response in a self-contained nanotube-based nanoelectromechanical structure.

  2. Totally implantable total artificial heart and ventricular assist device with multipurpose miniature electromechanical energy system.

    PubMed

    Takatani, S; Orime, Y; Tasai, K; Ohara, Y; Naito, K; Mizuguchi, K; Makinouchi, K; Damm, G; Glueck, J; Ling, J

    1994-01-01

    A multipurpose miniature electromechanical energy system has been developed to yield a compact, efficient, durable, and biocompatible total artificial heart (TAH) and ventricular assist device (VAD). Associated controller-driver electronics were recently miniaturized and converted into hybrid circuits. The hybrid controller consists of a microprocessor and controller, motor driver, Hall sensor, and commutation circuit hybrids. The sizing study demonstrated that all these components can be incorporated in the pumping unit of the TAH and VAD, particularly in the centerpiece of the TAH and the motor housing of the VAD. Both TAH and VAD pumping units will start when their power line is connected to either the internal power pack or the external battery unit. As a redundant driving and diagnostic port, an emergency port was newly added and will be placed in subcutaneous location. In case of system failure, the skin will be cut down, and an external motor drive or a pneumatic driver will be connected to this port to run the TAH. This will minimize the circulatory arrest time. Overall efficiency of the TAH without the transcutaneous energy transmission system was 14-18% to deliver pump outputs of 4-9 L/min against the right and left afterload pressures of 25 and 100 mm Hg. The internal power requirement ranged from 6 to 13 W. The rechargeable batteries such as NiCd or NiMH with 1 AH capacity can run the TAH for 30-45 min. The external power requirement, when TETS efficiency of 75% was assumed, ranged from 8 to 18 W. The accelerated endurance test in the 42 degrees C saline bath demonstrated stable performance over 4 months. Long-term endurance and chronic animal studies will continue toward a system with 5 years durability by the year 2000.

  3. High performance AlScN thin film based surface acoustic wave devices with large electromechanical coupling coefficient

    SciTech Connect

    Wang, Wenbo; He, Xingli; Ye, Zhi E-mail: jl2@bolton.ac.uk; Wang, Xiaozhi; Mayrhofer, Patrick M.; Gillinger, Manuel; Bittner, Achim; Schmid, Ulrich

    2014-09-29

    AlN and AlScN thin films with 27% scandium (Sc) were synthesized by DC magnetron sputtering deposition and used to fabricate surface acoustic wave (SAW) devices. Compared with AlN-based devices, the AlScN SAW devices exhibit much better transmission properties. Scandium doping results in electromechanical coupling coefficient, K{sup 2}, in the range of 2.0% ∼ 2.2% for a wide normalized thickness range, more than a 300% increase compared to that of AlN-based SAW devices, thus demonstrating the potential applications of AlScN in high frequency resonators, sensors, and high efficiency energy harvesting devices. The coupling coefficients of the present AlScN based SAW devices are much higher than that of the theoretical calculation based on some assumptions for AlScN piezoelectric material properties, implying there is a need for in-depth investigations on the material properties of AlScN.

  4. Micro- and nano-force evaluation of bioengineered muscle cells: a non-contact two-dimensional biosensing using surface acoustic wave devices.

    PubMed

    Wong, Yoke-Rung

    2015-08-01

    A high degree of cell-generated force measurement is required to evaluate the biomechanical performance of bioengineered muscle tissues. However, the conventional cantilever types of direct force measurement methods have limitations in developing a non-contact two-dimensional force sensing device for a single muscle cell. In this paper, a method is proposed and discussed by using focused surface acoustic wave and magneto-optic Kerr measurements. To depict the capability of the proposed method, a conceptual design of such a sensory device is demonstrated for non-contact two-dimensional force measurement of a single muscle cell.

  5. Non-contact measurement of helicopter device position in wind tunnels with the use of optical videogrammetry method

    NASA Astrophysics Data System (ADS)

    Kuruliuk, K. A.; Kulesh, V. P.

    2016-10-01

    An optical videogrammetry method using one digital camera for non-contact measurements of geometric shape parameters, position and motion of models and structural elements of aircraft in experimental aerodynamics was developed. The tests with the use of this method for measurement of six components (three linear and three angular ones) of real position of helicopter device in wind tunnel flow were conducted. The distance between camera and test object was 15 meters. It was shown in practice that, in the conditions of aerodynamic experiment instrumental measurement error (standard deviation) for angular and linear displacements of helicopter device does not exceed 0,02° and 0.3 mm, respectively. Analysis of the results shows that at the minimum rotor thrust deviations are systematic and generally are within ± 0.2 degrees. Deviations of angle values grow with the increase of rotor thrust.

  6. Electromechanical switch

    NASA Astrophysics Data System (ADS)

    Antonuzzi, Anthony P.; Carignan, Donald J.

    1986-06-01

    A hardened electromechanical switch is disclosed. When appropriate electrical contacts and pick-offs are aligned, four switches close. The possible number of switch combinations selectable are 4095 based upon a base eight counting system. The switch has a counter section and a memory section. The counter section uses an odometer like device based upon octal. Each counter wheel of the counter section has an electrical pick-off that interacts with the memory section. In the memory section, a plurality of octal numbers, four, are entered into and locked thereon such that each counter set disk, four, therein has one octal number thereon. Electrical contacts are placed on the counter set disks of the memory section and these touch the pick-offs of the counter wheels which will simultaneously close on the four contacts of the counter set disk in only one of the 4095 combinations noted above.

  7. Realization of modes of satellite attitude motion with a small level of microaccelerations using electromechanical executive devices

    NASA Astrophysics Data System (ADS)

    Ignatov, A. I.; Sazonov, V. V.

    2012-09-01

    Quasi-static microaccelerations are estimated for a satellite specially designed to perform space experiments in the field of microgravity. Three modes of attitude motion of the spacecraft are considered: passive gravitational orientation, orbital orientation, and semi-passive gravitational orientation. In these modes the lengthwise axis of the satellite is directed along the local vertical, while solar arrays lie in the orbit plane. The second and third modes are maintained using electromechanical executive devices: flywheel engines or gyrodynes. Estimations of residual microaccelerations are performed with the help of mathematical modeling of satellite's attitude motion under the action of gravitational and aerodynamic moments, as well as the moment produced by the gyro system. It is demonstrated that all modes ensure rather low level of quasi-static microaccelerations on the satellite and provide for a fairly narrow region of variation for the vector of residual microacceleration. The semi-passive gravitational orientation ensures also a limited proper angular momentum of the gyro system.

  8. An investigation into the concurrent collection of human scent and epithelial skin cells using a non-contact sampling device.

    PubMed

    Caraballo, Norma Iris; Mendel, Julian; Holness, Howard; La Salvia, Joel; Moroose, Tina; Eckenrode, Brian; Stockham, Rex; Furton, Kenneth; Mills, DeEtta

    2016-09-01

    In criminal investigations, the collection of human scent often employs a non-contact, dynamic airflow device, known as the Scent Transfer Unit 100 (STU-100), to transfer volatile organic compounds (VOCs) from an object/person onto a collection material that is subsequently presented to human scent discriminating canines. Human scent is theorized to be linked to epithelial skin cells that are shed at a relatively constant rate allowing both scent and cellular material to be deposited into the environment and/or onto objects. Simultaneous collection of cellular material, with adequate levels of nuclear deoxyribonucleic acid (nDNA), and human scent using a non-invasive methodology would facilitate criminal investigations. This study evaluated the STU-100 for the concurrent collection of human scent and epithelial skin cells from a porous (paper) and non-porous (stainless steel bar) object that was held for a specified period of time in the dominant hand of twenty subjects (10 females and 10 males). Human scent analysis was performed using headspace static solid-phase microextraction with gas chromatography-mass spectrometry (HS-SPME/GC-MS). A polycarbonate filter was used to trap epithelial skin cells which, upon extraction, were subsequently analyzed, inter-laboratory, using the quantitative polymerase chain reaction (qPCR). The STU-100 proved to be inadequate for collecting the minimum number of epithelial skin cells required to obtain nuclear DNA concentrations above the limit of detection for the qPCR kit. With regard to its use for human scent collection, a reduction in the number and mass of compounds was observed when compared to samples that were directly collected. However, when the indirect collection of human scent from the two different objects was compared, a greater number and mass of compounds was observed from the non-porous object than from the porous object. This outcome suggests that the matrix composition of the scent source could affect the

  9. An investigation into the concurrent collection of human scent and epithelial skin cells using a non-contact sampling device.

    PubMed

    Caraballo, Norma Iris; Mendel, Julian; Holness, Howard; La Salvia, Joel; Moroose, Tina; Eckenrode, Brian; Stockham, Rex; Furton, Kenneth; Mills, DeEtta

    2016-09-01

    In criminal investigations, the collection of human scent often employs a non-contact, dynamic airflow device, known as the Scent Transfer Unit 100 (STU-100), to transfer volatile organic compounds (VOCs) from an object/person onto a collection material that is subsequently presented to human scent discriminating canines. Human scent is theorized to be linked to epithelial skin cells that are shed at a relatively constant rate allowing both scent and cellular material to be deposited into the environment and/or onto objects. Simultaneous collection of cellular material, with adequate levels of nuclear deoxyribonucleic acid (nDNA), and human scent using a non-invasive methodology would facilitate criminal investigations. This study evaluated the STU-100 for the concurrent collection of human scent and epithelial skin cells from a porous (paper) and non-porous (stainless steel bar) object that was held for a specified period of time in the dominant hand of twenty subjects (10 females and 10 males). Human scent analysis was performed using headspace static solid-phase microextraction with gas chromatography-mass spectrometry (HS-SPME/GC-MS). A polycarbonate filter was used to trap epithelial skin cells which, upon extraction, were subsequently analyzed, inter-laboratory, using the quantitative polymerase chain reaction (qPCR). The STU-100 proved to be inadequate for collecting the minimum number of epithelial skin cells required to obtain nuclear DNA concentrations above the limit of detection for the qPCR kit. With regard to its use for human scent collection, a reduction in the number and mass of compounds was observed when compared to samples that were directly collected. However, when the indirect collection of human scent from the two different objects was compared, a greater number and mass of compounds was observed from the non-porous object than from the porous object. This outcome suggests that the matrix composition of the scent source could affect the

  10. Non-Contact Printed Aluminum Metallization of Si Photovoltaic Devices: Preprint

    SciTech Connect

    Platt, H. A. S.; van Hest, M. F. A. M.; Li, Y.; Novak, J. P.

    2012-06-01

    Alternative solution-based techniques such as aerosol jet printing offer the dual benefits of contactless pattern deposition and high material utilization. We have used aerosol jet printing to investigate non-contact printed Al metal ink as a replacement for screen printed Al back contacts on wafer Si solar cells. This particle-based ink can be prepared at high loadings of 60 weight % metal, which enables rapid deposition of 1 - 10 um thick lines. Al lines printed on Si wafers and heated between 550 and 800 degrees C form low resistance contacts suitable for current extraction. The effectiveness of these printed Al back contacts has further been demonstrated by incorporating them into a series of 21 cm2 crystalline Si solar cells that produced a champion power conversion efficiency of 13%.

  11. Development and optimization of a noncontact optical device for online monitoring of jaundice in human subjects.

    PubMed

    Polley, Nabarun; Saha, Srimoyee; Singh, Soumendra; Adhikari, Aniruddha; Das, Sukhen; Choudhury, Bhaskar Roy; Pal, Samir Kumar

    2015-06-01

    Jaundice is one of the notable markers of liver malfunction in our body, revealing a significant rise in the concentration of an endogenous yellow pigment bilirubin. We have described a method for measuring the optical spectrum of our conjunctiva and derived pigment concentration by using diffused reflection measurement. The method uses no prior model and is expected to work across the races (skin color) encompassing a wide range of age groups. An optical fiber-based setup capable of measuring the conjunctival absorption spectrum from 400 to 800 nm is used to monitor the level of bilirubin and is calibrated with the value measured from blood serum of the same human subject. We have also developed software in the LabVIEW platform for use in online monitoring of bilirubin levels in human subjects by nonexperts. The results demonstrate that relative absorption at 460 and 600 nm has a distinct correlation with that of the bilirubin concentration measured from blood serum. Statistical analysis revealed that our proposed method is in agreement with the conventional biochemical method. The innovative noncontact, low-cost technique is expected to have importance in monitoring jaundice in developing/underdeveloped countries, where the inexpensive diagnosis of jaundice with minimally trained manpower is obligatory. PMID:26052974

  12. Development and optimization of a noncontact optical device for online monitoring of jaundice in human subjects

    NASA Astrophysics Data System (ADS)

    Polley, Nabarun; Saha, Srimoyee; Singh, Soumendra; Adhikari, Aniruddha; Das, Sukhen; Choudhury, Bhaskar Roy; Pal, Samir Kumar

    2015-06-01

    Jaundice is one of the notable markers of liver malfunction in our body, revealing a significant rise in the concentration of an endogenous yellow pigment bilirubin. We have described a method for measuring the optical spectrum of our conjunctiva and derived pigment concentration by using diffused reflection measurement. The method uses no prior model and is expected to work across the races (skin color) encompassing a wide range of age groups. An optical fiber-based setup capable of measuring the conjunctival absorption spectrum from 400 to 800 nm is used to monitor the level of bilirubin and is calibrated with the value measured from blood serum of the same human subject. We have also developed software in the LabVIEW platform for use in online monitoring of bilirubin levels in human subjects by nonexperts. The results demonstrate that relative absorption at 460 and 600 nm has a distinct correlation with that of the bilirubin concentration measured from blood serum. Statistical analysis revealed that our proposed method is in agreement with the conventional biochemical method. The innovative noncontact, low-cost technique is expected to have importance in monitoring jaundice in developing/underdeveloped countries, where the inexpensive diagnosis of jaundice with minimally trained manpower is obligatory.

  13. Micro-electromechanical Systems for Probing Novel Strain Physics and Innovative Strain Devices in 2D Materials

    NASA Astrophysics Data System (ADS)

    Christopher, Jason; Vutukuru, Mounika; Bishop, David; Swan, Anna; Goldberg, Bennett

    Straining 2D materials can dramatically change electrical, thermal and optical properties and can even cause unconventional behavior such as generating pseudo-magnetic fields. However attempts at probing these effects have been hindered by the difficulty involved with precisely straining these materials. Here we present micro-electromechanical systems (MEMS) as an ideal platform for straining 2D materials because they are readily compatible with existing electronics and their size makes them compatible with 2D materials. Additionally the MEMS platform does more than facilitate experimentation; by freeing us to think of strain as dynamical it makes a whole new class of devices practical for next generation technology. To demonstrate the power of this platform we have for the first time measured the strain response of the Raman and photoluminescence spectra of suspended MoS2, and measured the friction force between MoS2 and the MEMS structure. This talk will touch on the basics of designing MEMS structures for straining 2D materials, how to transfer 2D materials onto MEMS without break either, proof of concept experimental results, and next steps in developing the MEMS platform. This work is supported by NSF DMR Grant 1411008, and author J. Christopher thanks the NDSEG program for its support.

  14. The impact of rare earth cobalt permanent magnets on electromechanical device design

    NASA Technical Reports Server (NTRS)

    Fisher, R. L.; Studer, P. A.

    1979-01-01

    Specific motor designs which employ rare earth cobalt magnets are discussed with special emphasis on their unique properties and magnetic field geometry. In addition to performance improvements and power savings, high reliability devices are attainable. Both the mechanism and systems engineering should be aware of the new performance levels which are currently becoming available as a result of the rare earth cobalt magnets.

  15. Noncontacting devices to indicate deflection and vibration of turbopump internal rotating parts

    NASA Technical Reports Server (NTRS)

    Hamilton, D. B.; Ensminger, D.; Grieser, D. R.; Plummer, A. M.; Saccocio, E. J.; Kissel, J. W.

    1973-01-01

    The research is reported which was conducted to develop devices for measuring vibrations and deflections of parts, such as impellers, shafts, turbine wheels, and inducers in operating turbopumps. Three devices were developed to the breadboard stage: ultrasonic Doppler transducer, flash X-rays, and light-pipe reflectance. It was found that the X-ray technique is applicable to the shaft assembly and the turbine seal of the J-2 pump, and the light-pipe-reflectance device appears to be ideal for cryogenic pump sections.

  16. A process for the agile product realization of electromechanical devices (A-primed)

    SciTech Connect

    Forsythe, C.; Ashby, M.R.; Benavides, G.L.; Diegert, K.V.; Jones, R.E.; Longcope, D.B.; Parratt, S.W.

    1996-02-01

    This paper describes a product realization process developed at Sandia National Laboratories by the A-PRIMED project that integrates many of the key components of ``agile manufacturing`` (Nagel & Dove, 1992) into a complete, step-by-step, design-to-production process. For two separate product realization efforts, each geared to a different set of requirements, A-PRIMED demonstrated product realization of a custom device in less than a month. A-PRIMED used a discriminator (a precision electro mechanical device) as the demonstration device, but the process is readily adaptable to other electro mechanical products. The process begins with a qualified design parameter space (Diegert et al, 1995). From that point, the product realization process encompasses all facets of requirements development, analysis and testing, design, manufacturing, robot assembly and quality assurance, as well as product data management and concurrent engineering. In developing the product realization process, A-PRIMED employed an iterative approach whereby after each build, the process was reviewed and refinements were made on the basis of lessons learned. This paper describes the integration of project functions and product realization technologies to develop a product realization process that on repeated iterations, was proven successful.

  17. A process for the agile product realization of electro-mechanical devices

    SciTech Connect

    Forsythe, C.; Ashby, M.R.; Benavides, G.L.; Diegert, K.V.; Jones, R.E.; Longcope, D.B.; Parratt, S.W.

    1995-09-01

    This paper describes a product realization process developed and demonstrated at Sandia by the A-PRIMED (Agile Product Realization for Innovative Electro MEchanical Devices) project that integrates many of the key components of ``agile manufacturing`` into a complete, design-to-production process. Evidence indicates that the process has reduced the product realization cycle and assured product quality. Products included discriminators for a robotic quick change adapter and for an electronic defense system. These discriminators, built using A-PRIMED, met random vibration requirements and had life cycles that far surpass the performance obtained from earlier efforts.

  18. Heating-Rate-Triggered Carbon-Nanotube-based 3-Dimensional Conducting Networks for a Highly Sensitive Noncontact Sensing Device

    NASA Astrophysics Data System (ADS)

    Tai, Yanlong; Lubineau, Gilles

    2016-01-01

    Recently, flexible and transparent conductive films (TCFs) are drawing more attention for their central role in future applications of flexible electronics. Here, we report the controllable fabrication of TCFs for moisture-sensing applications based on heating-rate-triggered, 3-dimensional porous conducting networks through drop casting lithography of single-walled carbon nanotube (SWCNT)/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS) ink. How ink formula and baking conditions influence the self-assembled microstructure of the TCFs is discussed. The sensor presents high-performance properties, including a reasonable sheet resistance (2.1 kohm/sq), a high visible-range transmittance (>69%, PET = 90%), and good stability when subjected to cyclic loading (>1000 cycles, better than indium tin oxide film) during processing, when formulation parameters are well optimized (weight ratio of SWCNT to PEDOT:PSS: 1:0.5, SWCNT concentration: 0.3 mg/ml, and heating rate: 36 °C/minute). Moreover, the benefits of these kinds of TCFs were verified through a fully transparent, highly sensitive, rapid response, noncontact moisture-sensing device (5 × 5 sensing pixels).

  19. Heating-Rate-Triggered Carbon-Nanotube-based 3-Dimensional Conducting Networks for a Highly Sensitive Noncontact Sensing Device

    PubMed Central

    Tai, Yanlong; Lubineau, Gilles

    2016-01-01

    Recently, flexible and transparent conductive films (TCFs) are drawing more attention for their central role in future applications of flexible electronics. Here, we report the controllable fabrication of TCFs for moisture-sensing applications based on heating-rate-triggered, 3-dimensional porous conducting networks through drop casting lithography of single-walled carbon nanotube (SWCNT)/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS) ink. How ink formula and baking conditions influence the self-assembled microstructure of the TCFs is discussed. The sensor presents high-performance properties, including a reasonable sheet resistance (2.1 kohm/sq), a high visible-range transmittance (>69%, PET = 90%), and good stability when subjected to cyclic loading (>1000 cycles, better than indium tin oxide film) during processing, when formulation parameters are well optimized (weight ratio of SWCNT to PEDOT:PSS: 1:0.5, SWCNT concentration: 0.3 mg/ml, and heating rate: 36 °C/minute). Moreover, the benefits of these kinds of TCFs were verified through a fully transparent, highly sensitive, rapid response, noncontact moisture-sensing device (5 × 5 sensing pixels). PMID:26818091

  20. Enhancement of effective electromechanical coupling factor by mass loading in layered surface acoustic wave device structures

    NASA Astrophysics Data System (ADS)

    Tang, Gongbin; Han, Tao; Teshigahara, Akihiko; Iwaki, Takao; Hashimoto, Ken-ya

    2016-07-01

    This paper describes a drastic enhancement of the effective coupling factor K\\text{e}2 by mass loading in layered surface acoustic wave (SAW) device structures such as the ScAlN film/Si substrate structure. This phenomenon occurs when the piezoelectric layer exhibits a high acoustic wave velocity. The mass loading decreases the SAW velocity and causes SAW energy confinement close to the top surface where an interdigital transducer is placed. It is shown that this phenomenon is obvious even when an amorphous SiO2 film is deposited on the top surface for temperature compensation. This K\\text{e}2 enhancement was also found in various combinations of electrode, piezoelectric layer, and/or substrate materials. The existence of this phenomenon was verified experimentally using the ScAlN film/Si substrate structure.

  1. Simple yet accurate noncontact device for measuring the radius of curvature of a spherical mirror

    SciTech Connect

    Spiridonov, Maxim; Toebaert, David

    2006-09-10

    An easily reproducible device is demonstrated to be capable of measuring the radii of curvature of spherical mirrors, both convex and concave, without resorting to high-end interferometric or tactile devices. The former are too elaborate for our purposes,and the latter cannot be used due to the delicate nature of the coatings applied to mirrors used in high-power CO2 laser applications. The proposed apparatus is accurate enough to be useful to anyone using curved optics and needing a quick way to assess the values of the radii of curvature, be it for entrance quality control or trouble shooting an apparently malfunctioning optical system. Specifically, the apparatus was designed for checking 50 mm diameter resonator(typically flat or tens of meters concave) and telescope (typically some meters convex and concave) mirrors for a high-power CO2 laser, but it can easily be adapted to any other type of spherical mirror by a straightforward resizing.

  2. Simple yet accurate noncontact device for measuring the radius of curvature of a spherical mirror

    NASA Astrophysics Data System (ADS)

    Spiridonov, Maxim; Toebaert, David

    2006-09-01

    An easily reproducible device is demonstrated to be capable of measuring the radii of curvature of spherical mirrors, both convex and concave, without resorting to high-end interferometric or tactile devices. The former are too elaborate for our purposes, and the latter cannot be used due to the delicate nature of the coatings applied to mirrors used in high-power CO2 laser applications. The proposed apparatus is accurate enough to be useful to anyone using curved optics and needing a quick way to assess the values of the radii of curvature, be it for entrance quality control or trouble shooting an apparently malfunctioning optical system. Specifically, the apparatus was designed for checking 50 mm diameter resonator (typically flat or tens of meters concave) and telescope (typically some meters convex and concave) mirrors for a high-power CO2 laser, but it can easily be adapted to any other type of spherical mirror by a straightforward resizing.

  3. Graphene Quantum Dots Interfaced with Single Bacterial Spore for Bio-Electromechanical Devices: A Graphene Cytobot

    PubMed Central

    Sreeprasad, T. S.; Nguyen, Phong; Alshogeathri, Ahmed; Hibbeler, Luke; Martinez, Fabian; McNeil, Nolan; Berry, Vikas

    2015-01-01

    The nanoarchitecture and micromachinery of a cell can be leveraged to fabricate sophisticated cell-driven devices. This requires a coherent strategy to derive cell's mechanistic abilities, microconstruct, and chemical-texture towards such microtechnologies. For example, a microorganism's hydrophobic membrane encapsulating hygroscopic constituents allows it to sustainably withhold a high aquatic pressure. Further, it provides a rich surface chemistry available for nano-interfacing and a strong mechanical response to humidity. Here we demonstrate a route to incorporate a complex cellular structure into microelectromechanics by interfacing compatible graphene quantum dots (GQDs) with a highly responsive single spore microstructure. A sensitive and reproducible electron-tunneling width modulation of 1.63 nm within a network of GQDs chemically-secured on a spore was achieved via sporal hydraulics with a driving force of 299.75 Torrs (21.7% water at GQD junctions). The electron-transport activation energy and the Coulomb blockade threshold for the GQD network were 35 meV and 31 meV, respectively; while the inter-GQD capacitance increased by 1.12 folds at maximum hydraulic force. This is the first example of nano/bio interfacing with spores and will lead to the evolution of next-generation bio-derived microarchitectures, probes for cellular/biochemical processes, biomicrorobotic-mechanisms, and membranes for micromechanical actuation. PMID:25774962

  4. Analytical model of an Annular Momentum Control Device (AMCD) laboratory test model magnetic bearing actuator

    NASA Technical Reports Server (NTRS)

    Groom, N. J.

    1979-01-01

    An analytical model of an Annular Momentum Control Device (AMCD) laboratory test model magnetic bearing actuator with permanent magnet fluxbiasing is presented. An AMCD consists of a spinning annular rim which is suspended by a noncontacting linear electromagnetic spin motor. The actuator is treated as a lumped-parameter electromechanical system in the development of the model.

  5. Conceptual design of a noncontacting power transfer device for the ASPS Vernier system

    NASA Technical Reports Server (NTRS)

    Kroeger, J.; Drilling, J.; Gunderman, T.

    1984-01-01

    The conceptual of electrical power transfer across a magnetically controlled gap as discussed for several years. The design represents the culmination of the first serious attempt to design a very low force, noncontracting power transfer mechanism. The electromagnetic device advanced herein is an ironless, translatable secondary transformer in which one of the two coils is fixed to the entire magnetic core. The second coil is free to move within the core over the full range of motions required. The specific application considered for this design was the Vernier subsystem of the Annular Suspension and Pointing System (ASPS). The development of and rationale for the electromagnetics design is presented. Similar documentation is provided for the Electronics Design. The Appendices detail the results of small scale model tests, disturbance force calculations, the baseline transformer fabrication drawings, the AVS Converter Parts List, and model schematic diagrams.

  6. Electromechanical cryocooler

    DOEpatents

    Neufeld, K.W.

    1996-12-10

    An electromechanical cryocooler is disclosed for substantially reducing vibrations caused by the cooler. The direction of the force of the vibrations is measured and a counterforce sufficient to substantially reduce this vibration is calculated and generated. The counterforce is 180{degree} out of phase with the direction of the force of the vibrations. 3 figs.

  7. Electromechanical cryocooler

    DOEpatents

    Neufeld, Kenneth W.

    1996-01-01

    An electromechanical cryocooler is disclosed for substantially reducing vibrations caused by the cooler. The direction of the force of the vibrations is measured and a counterforce sufficient to substantially reduce this vibration is calculated and generated. The counterforce is 180.degree. out of phase with the direction of the force of the vibrations.

  8. Electromechanical Technician.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This document contains 25 units to consider for use in a tech prep competency profile for the occupation of electromechanical technician. All the units listed will not necessarily apply to every situation or tech prep consortium, nor will all the competencies within each unit be appropriate. Several units appear within each specific occupation and…

  9. Electromechanical Componentry. High-Technology Training Module.

    ERIC Educational Resources Information Center

    Lindemann, Don

    This training module on electromechanical components contains 10 units for a two-year vocational program packaging system equipment control course at Wisconsin Indianhead Technical College. This module describes the functions of electromechanical devices essential for understanding input/output devices for Programmable Logic Control (PLC)…

  10. Electromechanical cell lysis using a portable audio device: enabling challenging sample preparation at the point-of-care.

    PubMed

    Buser, J R; Wollen, A; Heiniger, E K; Byrnes, S A; Kauffman, P C; Ladd, P D; Yager, P

    2015-05-01

    Audio sources are ubiquitously available on portable electronic devices, including cell phones. Here we demonstrate lysis of Mycobacterium marinum and Staphylococcus epidermidis bacteria utilizing a portable audio device coupled with a simple and inexpensive electromagnetic coil. The resulting alternating magnetic field rotates a magnet in a tube with the sample and glass beads, lysing the cells and enabling sample preparation for these bacteria anywhere there is a cell phone, mp3 player, laptop, or other device with a headphone jack. PMID:25797443

  11. Bilayer Graphene Electromechanical Systems

    NASA Astrophysics Data System (ADS)

    Champagne, Alexandre; Storms, Matthew; Yigen, Serap; Reulet, Bertrand

    Bilayer graphene is an outstanding electromechanical system, and its electronic and mechanical properties, as well as their coupling, are widely tunable. To the best of our knowledge, simultaneous charge transport and mechanical spectroscopy (via RF mixing) has not been realized in bilayer graphene. We present data showing clear electromechanical resonances in three suspended bilayer devices whose length range from 1 to 2 microns. We first describe the low-temperature current annealing of the devices which is crucial to achieve the transconductance, I -VG , necessary to implement a RF mixing detection method. We describe our RF mixing circuit and data. We measure clear mechanical resonances ranging in frequency from 50 to 140 MHz. We show that we can smoothly tune the resonance frequencies of our bilayer resonators with mechanical strain applied via a backgate voltage. We measure quality factors up to 4000. We briefly discuss the effects of the RF driving power on the dispersion of the mechanical resonance. We aim to use these high quality mechanical resonance as a mechanical sensor of the bilayer quantum Hall phase transitions. We show initial data of a bilayer mechanical resonance as a function of magnetic field and quantum Hall phase transitions.

  12. Electro-Mechanical Properties of Metal-Insulator-Metal Device Fabricated on Polymer Substrate Using Low-Temperature Process

    NASA Astrophysics Data System (ADS)

    Park, Sung Kyu; Han, Jeong In; Kim, Won Keun; Hong, Sung Jei; Kwak, Min Gi; Lee, Myung Jae; Chung, Kwan Soo

    2002-02-01

    High-performance metal-insulator-metal (MIM) devices on flexible polymer substrates were successfully fabricated without any defects such as cracks, delamination and blistering. This work examines the mechanical and electrical properties of MIM devices constructed using anodic Ta2O5 films. Using newly developed methods including stepped heating process and low-temperature post-annealing below 180°C, we obtained high-performances MIM devices on polymer substrates. Here, we propose the use of stacked bottom electrode and water barrier layer in order to enhance the ductility of the Ta electrode and to prevent blistering problems, respectively. Rutherford backscattering spectroscopy (RBS), auger electron spectroscopy (AES) and transmission electronic microscope (TEM) observations were performed for the structural investigation of the MIM devices on polymer substrates. Electrical measurements were also carried out for as-deposited and thermally treated MIM devices including Al/Ta/Ta2O5/Cr or Ti structures. They exhibit a low leakage current (below 10-7 A/cm2 at 2 MV) and reasonable breakdown voltage (5-7 MV/cm) with a uniformity of 92%. Finally, under low-temperature post-annealing conditions, The Current-Voltage (I-V) behaviors and conduction mechanisms of MIM devices on polymer substrates are discussed based on the results of electrical measurements, structural investigations and conduction band modeling.

  13. EMMA: Electromechanical Modeling in ALEGRA

    SciTech Connect

    1996-12-31

    To ensure high levels of deterrent capability in the 21st century, new stockpile stewardship principles are being embraced at Sandia National Laboratories. The Department of Energy Accelerated Strategic Computing Initiative (ASCI) program is providing the computational capacity and capability as well as funding the system and simulation software infrastructure necessary to provide accurate, precise and predictive modeling of important components and devices. An important class of components require modeling of piezoelectric and ferroceramic materials. The capability to run highly resolved simulations of these types of components on the ASCI parallel computers is being developed at Sandia in the ElectroMechanical Modeling in Alegra (EMMA) code. This a simulation capability being developed at Sandia National Laboratories for high-fidelity modeling of electromechanical devices. these devices can produce electrical current arising from material changes due to shock impact or explosive detonation.

  14. Evaluation of Qualitative Changes in Simulated Periodontal Ligament and Alveolar Bone Using a Noncontact Electromagnetic Vibration Device with a Laser Displacement Sensor.

    PubMed

    Kobayashi, Hiroshi; Hayashi, Makoto; Yamaoka, Masaru; Yasukawa, Takuya; Ibi, Haruna; Ogiso, Bunnai

    2016-01-01

    Evaluating periodontal tissue condition is an important diagnostic parameter in periodontal disease. Noncontact electromagnetic vibration device (NEVD) was previously developed to monitor this condition using mechanical parameters. However, this system requires accelerometer on the target tooth. This study assessed application of laser displacement sensor (LDS) to NEVD without accelerometer using experimental tooth models. Tooth models consisted of cylindrical rod, a tissue conditioner, and polyurethane or polyurethane foam to simulate tooth, periodontal ligament, and alveolar bone, respectively. Tissue conditioner was prepared by mixing various volumes of liquid with powder. Mechanical parameters (resonant frequency, elastic modulus, and coefficient of viscosity) were assessed using NEVD with the following methods: Group A, measurement with accelerometer; Group B, measurement with LDS in the presence of accelerometer; and Group C, measurement with LDS in the absence of accelerometer. Mechanical parameters significantly decreased with increasing liquid volume. Significant differences were also observed between the polyurethane and polyurethane foam models. Meanwhile, no statistically significant differences were observed between Groups A and B; however, most mechanical parameters in Group C were significantly larger and more distinguishable than those of Groups A and B. LDS could measure mechanical parameters more accurately and clearly distinguished the different periodontal ligament and alveolar bone conditions. PMID:27274995

  15. Use of a laser displacement sensor with a non-contact electromagnetic vibration device for assessment of simulated periodontal tissue conditions.

    PubMed

    Kobayashi, Hiroshi; Yamaoka, Masaru; Hayashi, Makoto; Ogiso, Bunnai

    2016-01-01

    A non-contact electromagnetic vibration device (NEVD) was previously developed to monitor the condition of periodontal tissues by assessing mechanical parameters. This system requires placement of an accelerometer on the target tooth, to detect vibration. Using experimental tooth models, we evaluated the performance of an NEVD system with a laser displacement sensor (LDS), which does not need an accelerometer. Simulated teeth (polyacetal rods) were submerged at various depths in simulated bone (polyurethane or polyurethane foam) containing simulated periodontal ligament (tissue conditioner). Then, mechanical parameters (resonant frequency, elastic modulus, and viscosity coefficient) were assessed using the NEVD with the following detection methods: Group 1, measurement with an accelerometer; Group 2, measurement with an LDS in the presence of the accelerometer; and Group 3, measurement with an LDS in the absence of the accelerometer. Statistical analyses were performed using nonparametric methods (n = 5) (P < 0.05). The three mechanical parameters significantly increased with increasing depth. In addition, the mechanical parameters significantly differed between the polyurethane and polyurethane foam models. Although Groups 1 and 2 did not significantly differ, most all mechanical parameters in Group 3 were significantly larger and more distinguishable than those in Groups 1 and 2. The LDS was more accurate in measuring mechanical parameters and better able to differentiate periodontal tissue conditions. (J Oral Sci 58, 93-99, 2016). PMID:27021545

  16. Evaluation of Qualitative Changes in Simulated Periodontal Ligament and Alveolar Bone Using a Noncontact Electromagnetic Vibration Device with a Laser Displacement Sensor

    PubMed Central

    Kobayashi, Hiroshi; Hayashi, Makoto; Yamaoka, Masaru; Yasukawa, Takuya; Ibi, Haruna; Ogiso, Bunnai

    2016-01-01

    Evaluating periodontal tissue condition is an important diagnostic parameter in periodontal disease. Noncontact electromagnetic vibration device (NEVD) was previously developed to monitor this condition using mechanical parameters. However, this system requires accelerometer on the target tooth. This study assessed application of laser displacement sensor (LDS) to NEVD without accelerometer using experimental tooth models. Tooth models consisted of cylindrical rod, a tissue conditioner, and polyurethane or polyurethane foam to simulate tooth, periodontal ligament, and alveolar bone, respectively. Tissue conditioner was prepared by mixing various volumes of liquid with powder. Mechanical parameters (resonant frequency, elastic modulus, and coefficient of viscosity) were assessed using NEVD with the following methods: Group A, measurement with accelerometer; Group B, measurement with LDS in the presence of accelerometer; and Group C, measurement with LDS in the absence of accelerometer. Mechanical parameters significantly decreased with increasing liquid volume. Significant differences were also observed between the polyurethane and polyurethane foam models. Meanwhile, no statistically significant differences were observed between Groups A and B; however, most mechanical parameters in Group C were significantly larger and more distinguishable than those of Groups A and B. LDS could measure mechanical parameters more accurately and clearly distinguished the different periodontal ligament and alveolar bone conditions. PMID:27274995

  17. Evaluation of Qualitative Changes in Simulated Periodontal Ligament and Alveolar Bone Using a Noncontact Electromagnetic Vibration Device with a Laser Displacement Sensor.

    PubMed

    Kobayashi, Hiroshi; Hayashi, Makoto; Yamaoka, Masaru; Yasukawa, Takuya; Ibi, Haruna; Ogiso, Bunnai

    2016-01-01

    Evaluating periodontal tissue condition is an important diagnostic parameter in periodontal disease. Noncontact electromagnetic vibration device (NEVD) was previously developed to monitor this condition using mechanical parameters. However, this system requires accelerometer on the target tooth. This study assessed application of laser displacement sensor (LDS) to NEVD without accelerometer using experimental tooth models. Tooth models consisted of cylindrical rod, a tissue conditioner, and polyurethane or polyurethane foam to simulate tooth, periodontal ligament, and alveolar bone, respectively. Tissue conditioner was prepared by mixing various volumes of liquid with powder. Mechanical parameters (resonant frequency, elastic modulus, and coefficient of viscosity) were assessed using NEVD with the following methods: Group A, measurement with accelerometer; Group B, measurement with LDS in the presence of accelerometer; and Group C, measurement with LDS in the absence of accelerometer. Mechanical parameters significantly decreased with increasing liquid volume. Significant differences were also observed between the polyurethane and polyurethane foam models. Meanwhile, no statistically significant differences were observed between Groups A and B; however, most mechanical parameters in Group C were significantly larger and more distinguishable than those of Groups A and B. LDS could measure mechanical parameters more accurately and clearly distinguished the different periodontal ligament and alveolar bone conditions.

  18. Use of a laser displacement sensor with a non-contact electromagnetic vibration device for assessment of simulated periodontal tissue conditions.

    PubMed

    Kobayashi, Hiroshi; Yamaoka, Masaru; Hayashi, Makoto; Ogiso, Bunnai

    2016-01-01

    A non-contact electromagnetic vibration device (NEVD) was previously developed to monitor the condition of periodontal tissues by assessing mechanical parameters. This system requires placement of an accelerometer on the target tooth, to detect vibration. Using experimental tooth models, we evaluated the performance of an NEVD system with a laser displacement sensor (LDS), which does not need an accelerometer. Simulated teeth (polyacetal rods) were submerged at various depths in simulated bone (polyurethane or polyurethane foam) containing simulated periodontal ligament (tissue conditioner). Then, mechanical parameters (resonant frequency, elastic modulus, and viscosity coefficient) were assessed using the NEVD with the following detection methods: Group 1, measurement with an accelerometer; Group 2, measurement with an LDS in the presence of the accelerometer; and Group 3, measurement with an LDS in the absence of the accelerometer. Statistical analyses were performed using nonparametric methods (n = 5) (P < 0.05). The three mechanical parameters significantly increased with increasing depth. In addition, the mechanical parameters significantly differed between the polyurethane and polyurethane foam models. Although Groups 1 and 2 did not significantly differ, most all mechanical parameters in Group 3 were significantly larger and more distinguishable than those in Groups 1 and 2. The LDS was more accurate in measuring mechanical parameters and better able to differentiate periodontal tissue conditions. (J Oral Sci 58, 93-99, 2016).

  19. Non-contact handling device

    SciTech Connect

    Reece, Mark; Knorovsky, Gerald A.; MacCallum, Danny O.

    2007-05-15

    A pressurized fluid handling nozzle has a body with a first end and a second end, a fluid conduit and a recess at the second end. The first end is configured for connection to a pressurized fluid source. The fluid conduit has an inlet at the first end and an outlet at the recess. The nozzle uses the Bernoulli effect for lifting a part.

  20. Modeling of dielectric elastomer as electromechanical resonator

    SciTech Connect

    Li, Bo Liu, Lei; Chen, Hualing; Jia, Shuhai; Zhang, Junshi; Li, Dichen

    2014-09-28

    Dielectric elastomers (DEs) feature nonlinear dynamics resulting from an electromechanical coupling. Under alternating voltage, the DE resonates with tunable performances. We present an analysis of the nonlinear dynamics of a DE as electromechanical resonator (DEER) configured as a pure shear actuator. A theoretical model is developed to characterize the complex performance under different boundary conditions. Physical mechanisms are presented and discussed. Chaotic behavior is also predicted, illustrating instabilities in the dynamics. The results provide a guide to the design and application of DEER in haptic devices.

  1. Modeling of dielectric elastomer as electromechanical resonator

    NASA Astrophysics Data System (ADS)

    Li, Bo; Zhang, Junshi; Liu, Lei; Chen, Hualing; Jia, Shuhai; Li, Dichen

    2014-09-01

    Dielectric elastomers (DEs) feature nonlinear dynamics resulting from an electromechanical coupling. Under alternating voltage, the DE resonates with tunable performances. We present an analysis of the nonlinear dynamics of a DE as electromechanical resonator (DEER) configured as a pure shear actuator. A theoretical model is developed to characterize the complex performance under different boundary conditions. Physical mechanisms are presented and discussed. Chaotic behavior is also predicted, illustrating instabilities in the dynamics. The results provide a guide to the design and application of DEER in haptic devices.

  2. Noncontact Temperature Measurement

    NASA Technical Reports Server (NTRS)

    Lee, Mark C. (Editor)

    1988-01-01

    Noncontact temperature measurement has been identified as one of the eight advanced technology development (ATD) areas to support the effort of the Microgravity Science and Applications Division in developing six Space Station flight experiment facilities. This two-day workshop was an opportunity for all six disciplines to present their requirements on noncontact temperature measurement and to discuss state-of-the-art developments. Multi-color pyrometry, laser pyrometry and radiometric imaging techniques are addressed.

  3. Electromechanical acoustic liner

    NASA Technical Reports Server (NTRS)

    Sheplak, Mark (Inventor); Cattafesta, III, Louis N. (Inventor); Nishida, Toshikazu (Inventor); Horowitz, Stephen Brian (Inventor)

    2007-01-01

    A multi-resonator-based system responsive to acoustic waves includes at least two resonators, each including a bottom plate, side walls secured to the bottom plate, and a top plate disposed on top of the side walls. The top plate includes an orifice so that a portion of an incident acoustical wave compresses gas in the resonators. The bottom plate or the side walls include at least one compliant portion. A reciprocal electromechanical transducer coupled to the compliant portion of each of the resonators forms a first and second transducer/compliant composite. An electrical network is disposed between the reciprocal electromechanical transducer of the first and second resonator.

  4. Elevation scanning laser/multi-sensor hazard detection system controller and mirror/mast speed control components. [roving vehicle electromechanical devices

    NASA Technical Reports Server (NTRS)

    Craig, J.; Yerazunis, S. W.

    1978-01-01

    The electro-mechanical and electronic systems involved with pointing a laser beam from a roving vehicle along a desired vector are described. A rotating 8 sided mirror, driven by a phase-locked dc motor servo system, and monitored by a precision optical shaft encoder is used. This upper assembly is then rotated about an orthogonal axis to allow scanning into all 360 deg around the vehicle. This axis is also driven by a phase locked dc motor servo-system, and monitored with an optical shaft encoder. The electronics are realized in standard TTL integrated circuits with UV-erasable proms used to store desired coordinates of laser fire. Related topics such as the interface to the existing test vehicle are discussed.

  5. Electromechanical flight control actuator

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The feasibility of using an electromechanical actuator (EMA) as the primary flight control equipment in aerospace flight is examined. The EMA motor design is presented utilizing improved permanent magnet materials. The necessary equipment to complete a single channel EMA using the single channel power electronics breadboard is reported. The design and development of an improved rotor position sensor/tachometer is investigated.

  6. Electromechanical Technician Skills Questionnaire.

    ERIC Educational Resources Information Center

    Anoka-Hennepin Technical Coll., Minneapolis, MN.

    This document contains test items to measure the job skills of electromechanical technicians. Questions are organized in four sections that cover the following topics: (1) shop math; (2) electricity and electronics; (3) mechanics and machining; and (4) plumbing, heating, ventilation and air conditioning, and welding skills. Questions call for…

  7. Noncontacting electrokinetography system

    NASA Technical Reports Server (NTRS)

    Davis, J. G.; Hickman, D. M.

    1979-01-01

    Noncontact acoustic technique utilizing air-coupled ultrasonic transducers for measuring motion of chest wall during cardiac cycle gives information on changes in size and compliance of heart ventricles. Information is digitized and fed to microprocessor for rapid storage and analysis for aid in diagnosis of heart condition.

  8. Noncontact Electromagnetic Vibration Source

    NASA Technical Reports Server (NTRS)

    Namkung, Min; Fulton, James P.; Wincheski, Buzz A.

    1994-01-01

    Metal aircraft skins scanned rapidly in vibration tests. Relatively simple combination of permanent magnets and electromagnet serves as noncontact vibration source for nondestructive testing of metal aircraft skins. In test, source excites vibrations, and vibration waveforms measured, then analyzed for changes in resonances signifying cracks and other flaws.

  9. Electromechanics of graphene spirals

    SciTech Connect

    Korhonen, Topi; Koskinen, Pekka

    2014-12-15

    Among the most fascinating nanostructure morphologies are spirals, hybrids of somewhat obscure topology and dimensionality with technologically attractive properties. Here, we investigate mechanical and electromechanical properties of graphene spirals upon elongation by using density-functional tight-binding, continuum elasticity theory, and classical force field molecular dynamics. It turns out that electronic properties are governed by interlayer interactions as opposed to strain effects. The structural behavior is governed by van der Waals interaction: in its absence spirals unfold with equidistant layer spacings, ripple formation at spiral perimeter, and steadily increasing axial force; in its presence, on the contrary, spirals unfold via smooth local peeling, complex geometries, and nearly constant axial force. These electromechanical trends ought to provide useful guidelines not only for additional theoretical investigations but also for forthcoming experiments on graphene spirals.

  10. Noncontact simultaneous dual wavelength photoplethysmography: A further step toward noncontact pulse oximetry

    SciTech Connect

    Humphreys, Kenneth; Ward, Tomas; Markham, Charles

    2007-04-15

    We present a camera-based device capable of capturing two photoplethysmographic (PPG) signals at two different wavelengths simultaneously, in a remote noncontact manner. The system comprises a complementary metal-oxide semiconductor camera and dual wavelength array of light emitting diodes (760 and 880 nm). By alternately illuminating a region of tissue with each wavelength of light, and detecting the backscattered photons with the camera at a rate of 16 frames/wavelength s, two multiplexed PPG wave forms are simultaneously captured. This process is the basis of pulse oximetry, and we describe how, with the inclusion of a calibration procedure, this system could be used as a noncontact pulse oximeter to measure arterial oxygen saturation (S{sub p}O{sub 2}) remotely. Results from an experiment on ten subjects, exhibiting normal S{sub p}O{sub 2} readings, that demonstrate the instrument's ability to capture signals from a range of subjects under realistic lighting and environmental conditions are presented. We compare the signals captured by the noncontact system to a conventional PPG signal captured concurrently from a finger, and show by means of a J. Bland and D. Altman [Lancet 327, 307 (1986); Statistician 32, 307 (1983)] test, the noncontact device to be comparable to a contact device as a monitor of heart rate. We highlight some considerations that should be made when using camera-based ''integrative'' sampling methods and demonstrate through simulation, the suitability of the captured PPG signals for application of existing pulse oximetry calibration procedures.

  11. Noncontact simultaneous dual wavelength photoplethysmography: A further step toward noncontact pulse oximetry

    NASA Astrophysics Data System (ADS)

    Humphreys, Kenneth; Ward, Tomas; Markham, Charles

    2007-04-01

    We present a camera-based device capable of capturing two photoplethysmographic (PPG) signals at two different wavelengths simultaneously, in a remote noncontact manner. The system comprises a complementary metal-oxide semiconductor camera and dual wavelength array of light emitting diodes (760 and 880nm). By alternately illuminating a region of tissue with each wavelength of light, and detecting the backscattered photons with the camera at a rate of 16frames/wavelengths, two multiplexed PPG wave forms are simultaneously captured. This process is the basis of pulse oximetry, and we describe how, with the inclusion of a calibration procedure, this system could be used as a noncontact pulse oximeter to measure arterial oxygen saturation (SpO2) remotely. Results from an experiment on ten subjects, exhibiting normal SpO2 readings, that demonstrate the instrument's ability to capture signals from a range of subjects under realistic lighting and environmental conditions are presented. We compare the signals captured by the noncontact system to a conventional PPG signal captured concurrently from a finger, and show by means of a J. Bland and D. Altman [Lancet 327, 307 (1986); Statistician 32, 307 (1983)] test, the noncontact device to be comparable to a contact device as a monitor of heart rate. We highlight some considerations that should be made when using camera-based "integrative" sampling methods and demonstrate through simulation, the suitability of the captured PPG signals for application of existing pulse oximetry calibration procedures.

  12. Electromechanical resistive switching via back-to-back Schottky junctions

    SciTech Connect

    Li, Lijie

    2015-09-15

    The physics of the electromechanical resistive switching is uncovered using the theory of back-to-back Schottky junctions combined with the quantum domain space charge transport. A theoretical model of the basic element of resistive switching devices realized by the metal-ZnO nanowires-metal structure has been created and analyzed. Simulation results show that the reverse biased Schottky junction and the air gap impedance dominate the current-voltage relation at higher external voltages; thereby electromechanically varying the air gap thickness causes the device exhibit resistive tuning characteristics. As the device dimension is in nanometre scale, investigation of the model based on quantum mechanics has also been conducted.

  13. Electromechanical Limits of Polymersomes

    NASA Astrophysics Data System (ADS)

    Aranda-Espinoza, H.; Bermudez, H.; Bates, F. S.; Discher, D. E.

    2001-11-01

    Self-assembled membranes of amphiphilic diblock copolymers enable comparisons of cohesiveness with lipid membranes over the range of hydrophobic thicknesses d = 3-15 nm. At zero mechanical tension the breakdown potential Vc for polymersomes with d = 15 nm is 9 V, compared to 1 V for liposomes with d = 3 nm. Nonetheless, electromechanical stresses at breakdown universally exhibit a V2c dependence, and membrane capacitance shows the expected strong d dependence, conforming to simple thermodynamic models. The viscous nature of the diblock membranes is apparent in the protracted postporation dynamics.

  14. Electromechanical response of silicone dielectric elastomers

    NASA Astrophysics Data System (ADS)

    Cârlescu, V.; Prisăcaru, G.; Olaru, D.

    2016-08-01

    This paper presents an experimental technique to investigate the electromechanical properties of silicone dielectric elastomers actuated with high DC electric fields. A non-contact measurement technique is used to capture and monitor the thickness strain (contraction) of a circular film placed between two metallic disks electrodes. Two active fillers such as silica (10, 15 and 30 wt%) and barium titanate (5 and 15 wt%) were incorporated in order to increase the actuation performance. Thickness strain was measured at HV stimuli up to 4.5 kV and showed a quadratic dependence against applied electric field indicating that the induced strain is triggered by the Maxwell effect and/or electrostriction phenomenon as reported in literature. The actuation process evidences a rapid contraction upon HV activation and a slowly relaxation when the electrodes are short-circuit due to visco-elastic nature of elastomers. A maximum of 1.22 % thickness strain was obtained at low actuating field intensity (1.5 V/pm) comparable with those reported in literature for similar dielectric elastomer materials.

  15. Electromechanical Energy Transduction for Hybrid Vehicles

    NASA Astrophysics Data System (ADS)

    Reddy Vanja, Sridhar; Kelly, Michael W.; Caruso, A. N.

    2010-03-01

    Hybrid vehicle technology seeks to reduce the total energy consumption used for vehicle locomotion by recovering and reutilizing kinetic energy that is otherwise unrecovered or dissipated in conventional vehicle deceleration. The goal of the work is to determine the transduction mechanisms that work towards a Carnot efficiency without considering constraints or limitations placed by cost or materials. Specifically, this talk will present ideal thermodynamic models of energy exchange between mechanical, electrostatic, electromechanical and electrochemical devices with a goal of projecting an ideal hybrid vehicle.

  16. Circuit For Control Of Electromechanical Prosthetic Hand

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr.

    1995-01-01

    Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.

  17. Electromechanical x-ray generator

    DOEpatents

    Watson, Scott A; Platts, David; Sorensen, Eric B

    2016-05-03

    An electro-mechanical x-ray generator configured to obtain high-energy operation with favorable energy-weight scaling. The electro-mechanical x-ray generator may include a pair of capacitor plates. The capacitor plates may be charged to a predefined voltage and may be separated to generate higher voltages on the order of hundreds of kV in the AK gap. The high voltage may be generated in a vacuum tube.

  18. Microwave Nano-abacus Electro-mechanical Oscillator

    NASA Astrophysics Data System (ADS)

    Peng, Haibing; Chang, C. W.; Aloni, S.; Yuzvinsky, T. D.; Zettl, A.

    2007-03-01

    We describe nanoscale electromechanical oscillators capable of operating in ambient-pressure air at room temperature with unprecedented fundamental resonance frequency of ˜4 GHz. The devices, created from suspended carbon nanotubes loaded abacus-style with inertial metal clamps yielding short effective beam lengths, open windows for immediate practical microwave frequency nanoelectromechanical systems (NEMS) applications.

  19. The electro-optical characteristics of liquid crystal device in multi-component liquid crystal mixture system with non-contact photo-induced vertical alignment mode

    NASA Astrophysics Data System (ADS)

    Lin, Fa-Hsin; Ho, Czung-Yu; Lee, Jiunn-Yih

    2012-05-01

    In previous studies, we mixed photo-curable acrylic pre-polymer into negative dielectric anisotropy nematic type liquid crystal (N-type LC, NLC) to obtain a NLC/photo-curable acrylic pre-polymer mixture solution (NLC mixture system). After irradiation with UV light of fixed intensity, we successfully fabricated copolymer films with vertical alignment effect among the LC molecules. In this study, we propose a new type of multi-component LC mixture system by mixing chiral smectic type (SmA*) LC with homeotropic texture into NLC/photo-curable acrylic pre-polymer mixture system (NSLC mixture system). Our experimental results revealed that this SmA* LC exhibited the vertical alignment effect associated with LC molecules in the auxiliary LC mixture system. Moreover, we also discovered that altering the main chain type biphenol acrylic pre-polymer had drastic impact on the contrast ratio (CR) of the LC mixture system, with an increase of as much as 73%. More importantly, adding the SmA* LC can evidently increase the anchoring energy of the alignment film surface. We also further performed measurements, analyses, and discussions of electro-optical properties of devices fabricated from the new LC mixture systems.

  20. A noncontact temperature measurement method in polymerase chain reaction reactors

    NASA Astrophysics Data System (ADS)

    Sochivko, D. G.; Varlamov, D. A.; Fedorov, A. A.; Kurochkin, V. E.

    2016-04-01

    A new noncontact method for measuring temperatures of liquids, which is based on the fluorescent probes, is proposed. The method is intended for measuring temperatures of reaction media in reactors of devices for polymerase chain reactions in real time and can be used for determining dynamic temperature parameters.

  1. Non-contacting power transfer device

    NASA Technical Reports Server (NTRS)

    Studer, P. A.; Paulkovich, J. (Inventor)

    1982-01-01

    A transformer for coupling AC electrical energy from a stationary element to a rotating element without the use of sliding contacts is described. The transformer is of the rotary type and includes a ferrite core and two primary windings which are stationary with respect to a seconary winding which rotates within an annular cavity adjacent an axial bore in the core. The core is comprised of two cup type core halves. Electrical connection to the secondary winding is made through a split bobbin assembly which couples to a coaxial shaft assembly located in the axial bore. The electrical coupling to the coaxial shaft assembly is made through a continuous transverse channel connecting the axial bore with the annular cavity. The transverse channel forms a single air gap; however, it is not open directly to free space but is shielded by the magnetic permeable material of the core halves.

  2. A silicon electromechanical photodetector.

    PubMed

    Tallur, Siddharth; Bhave, Sunil A

    2013-06-12

    Optomechanical systems have enabled wide-band optical frequency conversion and multichannel all-optical radio frequency amplification. Realization of an on-chip silicon communication platform is limited by photodetectors needed to convert optical information to electrical signals for further signal processing. In this paper we present a coupled silicon microresonator, which converts near-IR optical intensity modulation at 174.2 MHz and 1.198 GHz into motional electrical current. This device emulates a photodetector which detects intensity modulation of continuous wave laser light in the full-width-at-half-maximum bandwidth of the mechanical resonance. The resonant principle of operation eliminates dark current challenges associated with convetional photodetectors. While the results presented here constitute a purely classical demonstration, the device can also potentially be extended to the quantum regime to realize a photon-phonon translator. PMID:23706144

  3. Quantum electromechanics on silicon nitride nanomembranes

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  4. Non-contact ECG monitoring

    NASA Astrophysics Data System (ADS)

    Smirnov, Alexey S.; Erlikh, Vadim V.; Kodkin, Vladimir L.; Keller, Andrei V.; Epishev, Vitaly V.

    2016-03-01

    The research is dedicated to non-contact methods of electrocardiography. The authors describe the routine of experimental procedure and suggest the approach to solving the problems which arise at indirect signal recording. The paper presents the results of experiments conducted by the authors, covers the flow charts of ECG recorders and reviews the drawbacks of filtering methods used in foreign equivalents.

  5. A Hybrid Actuation System Demonstrating Significantly Enhanced Electromechanical Performance

    NASA Technical Reports Server (NTRS)

    Su, Ji; Xu, Tian-Bing; Zhang, Shujun; Shrout, Thomas R.; Zhang, Qiming

    2004-01-01

    A hybrid actuation system (HYBAS) utilizing advantages of a combination of electromechanical responses of an electroactive polymer (EAP), an electrostrictive copolymer, and an electroactive ceramic single crystal, PZN-PT single crystal, has been developed. The system employs the contribution of the actuation elements cooperatively and exhibits a significantly enhanced electromechanical performance compared to the performances of the device made of each constituting material, the electroactive polymer or the ceramic single crystal, individually. The theoretical modeling of the performances of the HYBAS is in good agreement with experimental observation. The consistence between the theoretical modeling and experimental test make the design concept an effective route for the development of high performance actuating devices for many applications. The theoretical modeling, fabrication of the HYBAS and the initial experimental results will be presented and discussed.

  6. Noncontact measurement of angular deflection

    NASA Technical Reports Server (NTRS)

    Bryant, E. L.

    1978-01-01

    Technique for measuring instantaneous angular deflection of object requires no physical contact. Technique utilizes two flat refractors, converging lens, and different photocell. Distinction of method is its combination of optical and electromechanical components into feedback system in which measurement error is made to approach zero. Application is foreseen in measurement of torsional strain.

  7. Electromechanical simulations of dislocations

    NASA Astrophysics Data System (ADS)

    Skiba, Oxana; Gracie, Robert; Potapenko, Stanislav

    2013-04-01

    Improving the reliability of micro-electronic devices depends in part on developing a more in-depth understanding of dislocations because dislocations are barriers to charge carriers. To this end, the quasi-static simulation of discrete dislocations dynamics in materials under mechanical and electrical loads is presented. The simulations are based on the extended finite element method, where dislocations are modelled as internal discontinuities. The strong and weak forms of the boundary value problem for the coupled system are presented. The computation of the Peach-Koehler force using the J-integral is discussed. Examples to illustrate the accuracy of the simulations are presented. The motion of the network of the dislocations under different electrical and mechanical loads is simulated. It was shown that even in weak piezoelectric materials the effect of the electric field on plastic behaviour is significant.

  8. Nanoscale electromechanical parametric amplifier

    DOEpatents

    Aleman, Benjamin Jose; Zettl, Alexander

    2016-09-20

    This disclosure provides systems, methods, and apparatus related to a parametric amplifier. In one aspect, a device includes an electron source electrode, a counter electrode, and a pumping electrode. The electron source electrode may include a conductive base and a flexible conductor. The flexible conductor may have a first end and a second end, with the second end of the flexible conductor being coupled to the conductive base. A cross-sectional dimension of the flexible conductor may be less than about 100 nanometers. The counter electrode may be disposed proximate the first end of the flexible conductor and spaced a first distance from the first end of the flexible conductor. The pumping electrode may be disposed proximate a length of the flexible conductor and spaced a second distance from the flexible conductor.

  9. Electromechanical propellant control system actuator

    NASA Technical Reports Server (NTRS)

    Myers, W. Neill; Weir, Rae Ann

    1990-01-01

    New control mechanism technologies are currently being sought to provide alternatives to hydraulic actuation systems. The Propulsion Laboratory at Marshall Space Flight Center (MSFC) is involved in the development of electromechanical actuators (EMA's) for this purpose. Through this effort, an in-house designed electromechanical propellant valve actuator has been assembled and is presently being evaluated. This evaluation will allow performance comparisons between EMA and hydraulics systems. The in-house design consists of the following hardware: a three-phase brushless motor, a harmonic drive, and an output spline which will mate with current Space Shuttle Main Engine (SSME) propellant control valves. A resolver and associated electronics supply position feedback for the EMA. System control is provided by a solid-state electronic controller and power supply. Frequency response testing has been performed with further testing planned as hardware and test facilities become available.

  10. Active feedback cooling of massive electromechanical quartz resonators

    SciTech Connect

    Jahng, Junghoon; Lee, Manhee; Stambaugh, Corey; Bak, Wan; Jhe, Wonho

    2011-08-15

    We present a general active feedback cooling scheme for massive electromechanical quartz resonators. We cool down two kinds of macrosized quartz tuning forks and find several characteristic constants for this massive quartz-resonator feedback cooling, in good agreement with theoretical calculations. When combined with conventional cryogenic techniques and low-noise devices, one may reach the quantum sensitivity for macroscopic sensors. This may be useful for high sensitivity measurements and for quantum information studies.

  11. The electromechanical battery: The new kid on the block

    SciTech Connect

    Post, R.F.

    1993-08-01

    In a funded program at the Lawrence Livermore National Laboratory new materials and novel designs are being incorporated into a new approach to an old concept -- flywheel energy storage. Modular devices, dubbed ``electromechanical batteries`` (EMB) are being developed that should represent an important alternative to the electrochemical storage battery for use in electric vehicles or for stationary applications, such as computer back-up power or utility load-leveling.

  12. Membrane cholesterol modulates cochlear electromechanics.

    PubMed

    Brownell, William E; Jacob, Stefan; Hakizimana, Pierre; Ulfendahl, Mats; Fridberger, Anders

    2011-06-01

    Changing the concentration of cholesterol in the plasma membrane of isolated outer hair cells modulates electromotility and prestin-associated charge movement, suggesting that a similar manipulation would alter cochlear mechanics. We examined cochlear function before and after depletion of membrane cholesterol with methyl-β-cyclodextrin (MβCD) in an excised guinea pig temporal bone preparation. The mechanical response of the cochlear partition to acoustic and/or electrical stimulation was monitored using laser interferometry and time-resolved confocal microscopy. The electromechanical response in untreated preparations was asymmetric with greater displacements in response to positive currents. Exposure to MβCD increased the magnitude and asymmetry of the response, without changing the frequency tuning of sound-evoked mechanical responses or cochlear microphonic potentials. Sodium salicylate reversibly blocked the enhanced electromechanical response in cholesterol depleted preparations. The increase of sound-evoked vibrations during positive current injection was enhanced following MβCD in some preparations. Imaging was used to assess cellular integrity which remained unchanged after several hours of exposure to MβCD in several preparations. The enhanced electromechanical response reflects an increase in outer hair cell electromotility and may reveal features of cholesterol distribution and trafficking in outer hair cells. PMID:21373862

  13. Hybrid electromechanical actuator and actuation system

    NASA Technical Reports Server (NTRS)

    Su, Ji (Inventor); Xu, Tian-Bing (Inventor)

    2008-01-01

    A hybrid electromechanical actuator has two different types of electromechanical elements, one that expands in a transverse direction when electric power is applied thereto and one that contracts in a transverse direction when electric power is applied thereto. The two electromechanical elements are (i) disposed in relation to one another such that the transverse directions thereof are parallel to one another, and (ii) mechanically coupled to one another at least at two opposing edges thereof. Electric power is applied simultaneously to the elements.

  14. Noncontacting NDE for materials characterization

    SciTech Connect

    Telschow, K.L.

    1995-10-01

    This report describes research performed at the Idaho National Engineering Laboratory from May 1983 to September 1995, funded by the Interior Department`s Bureau of Mines, on ultrasonic methods (particularly noncontacting methods) for nondestructive evaluation and process control. The abilities of ultrasonic techniques to measure microstructural features in metals, ceramics, and composite materials were demonstrated. A major emphasis in this project was the development of noncontacting ultrasonic techniques, based on laser generation and detection of elastic waves, for process monitoring and control in high-temperature, harsh environments without close coupling to the material being processed. Laser ultrasonic measurements were utilized for in situ process monitoring during ceramic sintering, high temperature annealing, and molten metal solidification.

  15. Dissipation engineering in a coherent feedback electromechanical network

    NASA Astrophysics Data System (ADS)

    Kerckhoff, Joseph

    2014-03-01

    Modern superconducting microwave circuit experiments often consist of a quantum circuit under study, followed by a quantum-limited microwave amplifier. The subfield of quantum electromechanics, in which the quantum circuit is a mechanical resonator coupled to a microwave resonator, is no exception. However, a simple modification of the cables between these devices turns this open-loop, serial network into a fully-cryogenic, coherent feedback network. In effect, this easy-to-build network becomes a brand new kind of device, with useful and novel dynamics. Applied to an electromechanical context, the microwave and electromechanical dissipation is greatly modified through these closed loop dynamics, leading to dynamically tunable and phase-sensitive decay. We experimentally demonstrate that the microwave decay rate may be modulated by at least a factor of 10 at a rate greater than 104 times the mechanical response rate. Similarly, the mechanical state can be dynamically squeezed and unsqueezed. While we have only investigated dynamics in the classical regime, we expect analogous behavior in the quantum regime. Finally, this approach is suitable for both 3D and planar architectures. I will describe my observations of this network and the general utility of networks of modular quantum circuits to dissipation engineering. With support from the NRC, and partial support from DARPA QuEST, DARPA ORCHID, and the NSF PFC at JILA.

  16. Enhanced electromechanical behaviors of cellulose ZnO hybrid nanocomposites

    NASA Astrophysics Data System (ADS)

    Mun, Seongchoel; Min, Seung-Ki; Kim, Hyun Chan; Im, Jongbeom; Geddis, Demetris L.; Kim, Jaehwan

    2015-04-01

    Inorganic-organic hybrid composite has attracted as its combined synergistic properties. Cellulose based inorganicorganic hybrid composite was fabricated with semiconductive nanomaterials which has functionality of nanomaterial and biocompatibility piezoelectricity, high transparency and flexibility of cellulose electro active paper namely EAPap. ZnO is providing semiconductive functionality to EAPap for hybrid nanocomposite by simple chemical reaction. Cellulose- ZnO hybrid nanocomposite (CEZOHN) demonstrates novel electrical, photoelectrical and electromechanical behaviors. This paper deals with methods to improve electromechanical property of CEZOHN. The fabrication process is introduced briefly, charging mechanism and evaluation is studied with measured piezoelectric constant. And its candidate application will be discussed such as artificial muscle, energy harvester, strain sensor, flexible electrical device.

  17. Electromechanical instability in soft materials: Theory, experiments and applications

    NASA Astrophysics Data System (ADS)

    Suo, Zhigang

    2013-03-01

    Subject to a voltage, a membrane of a dielectric elastomer reduces thickness and expands area, possibly straining over 100%. The phenomenon is being developed as transducers for broad applications, including soft robots, adaptive optics, Braille displays, and electric generators. The behavior of dielectric elastomers is closely tied to electromechanical instability. This instability may limit the performance of devices, and may also be used to achieve giant actuation strains. This talk reviews the theory of dielectric elastomers, coupling large deformation and electric potential. The theory is developed within the framework of continuum mechanics and thermodynamics. The theory attempts to answer commonly asked questions. How do mechanics and electrostatics work together to generate large deformation? How efficiently can a material convert energy from one form to another? How do molecular processes affect macroscopic behavior? The theory is used to describe electromechanical instability, and is related to recent experiments.

  18. Strongly Coupled Nanotube Electromechanical Resonators.

    PubMed

    Deng, Guang-Wei; Zhu, Dong; Wang, Xin-He; Zou, Chang-Ling; Wang, Jiang-Tao; Li, Hai-Ou; Cao, Gang; Liu, Di; Li, Yan; Xiao, Ming; Guo, Guang-Can; Jiang, Kai-Li; Dai, Xing-Can; Guo, Guo-Ping

    2016-09-14

    Coupling an electromechanical resonator with carbon-nanotube quantum dots is a significant method to control both the electronic charge and the spin quantum states. By exploiting a novel microtransfer technique, we fabricate two separate strongly coupled and electrically tunable mechanical resonators for the first time. The frequency of the two resonators can be individually tuned by the bottom gates, and in each resonator, the electron transport through the quantum dot can be strongly affected by the phonon mode and vice versa. Furthermore, the conductance of either resonator can be nonlocally modulated by the other resonator through phonon-phonon interaction between the two resonators. Strong coupling is observed between the phonon modes of the two resonators, where the coupling strength larger than 200 kHz can be reached. This strongly coupled nanotube electromechanical resonator array provides an experimental platform for future studies of the coherent electron-phonon interaction, the phonon-mediated long-distance electron interaction, and entanglement state generation.

  19. Microwave non-contact imaging of subcutaneous human body tissues.

    PubMed

    Kletsov, Andrey; Chernokalov, Alexander; Khripkov, Alexander; Cho, Jaegeol; Druchinin, Sergey

    2015-10-01

    A small-size microwave sensor is developed for non-contact imaging of a human body structure in 2D, enabling fitness and health monitoring using mobile devices. A method for human body tissue structure imaging is developed and experimentally validated. Subcutaneous fat tissue reconstruction depth of up to 70 mm and maximum fat thickness measurement error below 2 mm are demonstrated by measurements with a human body phantom and human subjects. Electrically small antennas are developed for integration of the microwave sensor into a mobile device. Usability of the developed microwave sensor for fitness applications, healthcare, and body weight management is demonstrated.

  20. Microwave non-contact imaging of subcutaneous human body tissues

    PubMed Central

    Chernokalov, Alexander; Khripkov, Alexander; Cho, Jaegeol; Druchinin, Sergey

    2015-01-01

    A small-size microwave sensor is developed for non-contact imaging of a human body structure in 2D, enabling fitness and health monitoring using mobile devices. A method for human body tissue structure imaging is developed and experimentally validated. Subcutaneous fat tissue reconstruction depth of up to 70 mm and maximum fat thickness measurement error below 2 mm are demonstrated by measurements with a human body phantom and human subjects. Electrically small antennas are developed for integration of the microwave sensor into a mobile device. Usability of the developed microwave sensor for fitness applications, healthcare, and body weight management is demonstrated. PMID:26609415

  1. Electro-mechanical propulsion system

    SciTech Connect

    Stewart, C.F.; Stewart, J.K.

    1984-04-24

    An Electro-Mechanical Propulsion System for vehicles, wherein the prime mover, such as an internal combustion engine, drives an alternating voltage generator through a first shaft at a constant RPM controlled by a speed governor; and wherein the alternating voltage generator serves as a source of energy for an electrical energy conversion unit comprising a controlled rectifier, a polyphase signal generator, an analog control unit, and a regulated DC power supply, to further provide a variable power and frequency source for an AC traction motor coupled through a second shaft to the vehicle wheel drive system. Operator manual or pedal control of the system is further provided by a speed control potentiometer, An acceleration control potentiometer, and a torque control potentiometer.

  2. Micro electro-mechanical heater

    DOEpatents

    Oh, Yunje; Asif, Syed Amanulla Syed; Cyrankowski, Edward; Warren, Oden Lee

    2016-04-19

    A sub-micron scale property testing apparatus including a test subject holder and heating assembly. The assembly includes a holder base configured to couple with a sub-micron mechanical testing instrument and electro-mechanical transducer assembly. The assembly further includes a test subject stage coupled with the holder base. The test subject stage is thermally isolated from the holder base. The test subject stage includes a stage subject surface configured to receive a test subject, and a stage plate bracing the stage subject surface. The stage plate is under the stage subject surface. The test subject stage further includes a heating element adjacent to the stage subject surface, the heating element is configured to generate heat at the stage subject surface.

  3. Electromechanical properties of graphene drumheads.

    PubMed

    Klimov, Nikolai N; Jung, Suyong; Zhu, Shuze; Li, Teng; Wright, C Alan; Solares, Santiago D; Newell, David B; Zhitenev, Nikolai B; Stroscio, Joseph A

    2012-06-22

    We determined the electromechanical properties of a suspended graphene layer by scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) measurements, as well as computational simulations of the graphene-membrane mechanics and morphology. A graphene membrane was continuously deformed by controlling the competing interactions with a STM probe tip and the electric field from a back-gate electrode. The probe tip-induced deformation created a localized strain field in the graphene lattice. STS measurements on the deformed suspended graphene display an electronic spectrum completely different from that of graphene supported by a substrate. The spectrum indicates the formation of a spatially confined quantum dot, in agreement with recent predictions of confinement by strain-induced pseudomagnetic fields.

  4. Electromechanical performance of piezoelectric scanning mirrors for medical endoscopy

    PubMed Central

    Gilchrist, Kristin H.; Dausch, David E.; Grego, Sonia

    2012-01-01

    The electromechanical performance of piezoelectric scanning mirrors for endoscopy imaging is presented. The devices are supported by a single actuating cantilever to achieve a high fill factor, the ratio of mirror area to the combined mirror and actuator area. The largest fill factor devices (74%) achieved 10° mechanical scan range at +/−10V with a 300 μm long cantilever. The largest angular displacement of 30° mechanical scan range was obtained with a 500 μm long cantilever device with a 63% fill factor driven at 40 Vpp. A systematic investigation of device performance (displacement and speed) as a function of fabrication and operational parameters including the stress balance in the cantilever revealed unexpectedly large displacements with lack of inversion at the coercive field. An interpretation of the results is presented based on piezoelectric film domain orientation and clamping with supporting piezoelectric film characterization measurements. PMID:22773894

  5. Quantum electromechanics on silicon nitride nanomembranes

    PubMed Central

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

    2016-01-01

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

  6. Superconducting circuitry for quantum electromechanical systems

    NASA Astrophysics Data System (ADS)

    LaHaye, Matthew D.; Rouxinol, Francisco; Hao, Yu; Shim, Seung-Bo; Irish, Elinor K.

    2015-05-01

    Superconducting systems have a long history of use in experiments that push the frontiers of mechanical sensing. This includes both applied and fundamental research, which at present day ranges from quantum computing research and e orts to explore Planck-scale physics to fundamental studies on the nature of motion and the quantum limits on our ability to measure it. In this paper, we first provide a short history of the role of superconducting circuitry and devices in mechanical sensing, focusing primarily on efforts in the last decade to push the study of quantum mechanics to include motion on the scale of human-made structures. This background sets the stage for the remainder of the paper, which focuses on the development of quantum electromechanical systems (QEMS) that incorporate superconducting quantum bits (qubits), superconducting transmission line resonators and flexural nanomechanical elements. In addition to providing the motivation and relevant background on the physical behavior of these systems, we discuss our recent efforts to develop a particular type of QEMS that is based upon the Cooper-pair box (CPB) and superconducting coplanar waveguide (CPW) cavities, a system which has the potential to serve as a testbed for studying the quantum properties of motion in engineered systems.

  7. Quantum electromechanics on silicon nitride nanomembranes.

    PubMed

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

    2016-01-01

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

  8. Motion-compensated non-contact detection of heart rate

    NASA Astrophysics Data System (ADS)

    Yang, Lei; Liu, Ming; Dong, Liquan; Zhao, Yuejin; Liu, Xiaohua

    2015-12-01

    A new non-contact heart rate detection method based on the dual-wavelength technique is proposed and demonstrated experimentally. It is a well-known fact that the differences in the circuits of two detection modules result in different responses of two modules for motion artifacts. This poses a great challenge to compensate the motion artifacts during measurements. In order to circumvent this problem, we have proposed the amplitude spectrum and phase spectrum adaptive filter. Comparing with the time-domain adaptive filter and independent component analysis, the amplitude spectrum and phase spectrum adaptive filter can suppress the interference caused by the two circuit differences and effectively compensate the motion artifacts. To make the device is much compact and portable, a photoelectric probe is designed. The measurement distance is from several centimeters up to several meters. Moreover, the data obtained by using this non-contact detection system is compared with those of the conventional finger blood volume pulse (BVP) sensor by simultaneously measuring the heart rate of the subject. The data obtained from the proposed non-contact system are consistent and comparable with that of the BVP sensor.

  9. Fast Electromechanical Switches Based on Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Kaul, Anupama; Wong, Eric; Epp, Larry

    2008-01-01

    Electrostatically actuated nanoelectromechanical switches based on carbon nanotubes have been fabricated and tested in a continuing effort to develop high-speed switches for a variety of stationary and portable electronic equipment. As explained below, these devices offer advantages over electrostatically actuated microelectromechanical switches, which, heretofore, have represented the state of the art of rapid, highly miniaturized electromechanical switches. Potential applications for these devices include computer memories, cellular telephones, communication networks, scientific instrumentation, and general radiation-hard electronic equipment. A representative device of the present type includes a single-wall carbon nanotube suspended over a trench about 130 nm wide and 20 nm deep in an electrically insulating material. The ends of the carbon nanotube are connected to metal electrodes, denoted the source and drain electrodes. At bottom of the trench is another metal electrode, denoted the pull electrode (see figure). In the off or open switch state, no voltage is applied, and the nanotube remains out of contact with the pull electrode. When a sufficiently large electric potential (switching potential) is applied between the pull electrode and either or both of the source and drain electrodes, the resulting electrostatic attraction bends and stretches the nanotube into contact with the pull electrode, thereby putting the switch into the "on" or "closed" state, in which substantial current (typically as much as hundreds of nanoamperes) is conducted. Devices of this type for use in initial experiments were fabricated on a thermally oxidized Si wafer, onto which Nb was sputter-deposited for use as the pull-electrode layer. Nb was chosen because its refractory nature would enable it to withstand the chemical and thermal conditions to be subsequently imposed for growing carbon nanotubes. A 200- nm-thick layer of SiO2 was formed on top of the Nb layer by plasma

  10. Optical driven electromechanical transistor based on tunneling effect.

    PubMed

    Jin, Leisheng; Li, Lijie

    2015-04-15

    A new electromechanical transistor based on an optical driven vibrational ring structure has been postulated. In the device, optical power excites the ring structure to vibrate, which acts as the shuttle transporting electrons from one electrode to the other forming the transistor. The electrical current of the transistor is adjusted by the optical power. Coupled opto-electro-mechanical simulation has been performed. It is shown from the dynamic analysis that the stable working range of the transistor is much wider than that of the optical wave inside the cavity, i.e., the optical resonance enters nonperiodic states while the mechanical vibration of the ring is still periodic.

  11. Revolution of Sensors in Micro-Electromechanical Systems

    NASA Astrophysics Data System (ADS)

    Esashi, Masayoshi

    2012-08-01

    Microsensors realized by micro-electromechanical systems (MEMS) technology play a key role as the input devices of systems. In this report, the following sensors are reviewed: piezoresistive and capacitive pressure sensors, surface acoustic wave (SAW) wireless pressure sensors, tactile sensor networks for robots, accelerometers, angular velocity sensors (gyroscopes), range image sensors using optical scanners, infrared imagers, chemical sensing systems as Fourier transform infrared (FTIR) spectroscopy and gas chromatography, flow sensors for fluids, and medical sensors such as ultrafine optical-fiber blood pressure sensors and implantable pressure sensors.

  12. A multimode electromechanical parametric resonator array

    PubMed Central

    Mahboob, I.; Mounaix, M.; Nishiguchi, K.; Fujiwara, A.; Yamaguchi, H.

    2014-01-01

    Electromechanical resonators have emerged as a versatile platform in which detectors with unprecedented sensitivities and quantum mechanics in a macroscopic context can be developed. These schemes invariably utilise a single resonator but increasingly the concept of an array of electromechanical resonators is promising a wealth of new possibilities. In spite of this, experimental realisations of such arrays have remained scarce due to the formidable challenges involved in their fabrication. In a variation to this approach, we identify 75 harmonic vibration modes in a single electromechanical resonator of which 7 can also be parametrically excited. The parametrically resonating modes exhibit vibrations with only 2 oscillation phases which are used to build a binary information array. We exploit this array to execute a mechanical byte memory, a shift-register and a controlled-NOT gate thus vividly illustrating the availability and functionality of an electromechanical resonator array by simply utilising higher order vibration modes. PMID:24658349

  13. Six-Message Electromechanical Display System

    NASA Technical Reports Server (NTRS)

    Howard, Richard T.

    2007-01-01

    A proposed electromechanical display system would be capable of presenting as many as six distinct messages. In the proposed system, each display element would include a cylinder having a regular hexagonal cross section.

  14. Circuit electromechanics with single photon strong coupling

    SciTech Connect

    Xue, Zheng-Yuan Yang, Li-Na; Zhou, Jian

    2015-07-13

    In circuit electromechanics, the coupling strength is usually very small. Here, replacing the capacitor in circuit electromechanics by a superconducting flux qubit, we show that the coupling among the qubit and the two resonators can induce effective electromechanical coupling which can attain the strong coupling regime at the single photon level with feasible experimental parameters. We use dispersive couplings among two resonators and the qubit while the qubit is also driven by an external classical field. These couplings form a three-wave mixing configuration among the three elements where the qubit degree of freedom can be adiabatically eliminated, and thus results in the enhanced coupling between the two resonators. Therefore, our work constitutes the first step towards studying quantum nonlinear effect in circuit electromechanics.

  15. Flexoelectric MEMS: towards an electromechanical strain diode

    NASA Astrophysics Data System (ADS)

    Bhaskar, U. K.; Banerjee, N.; Abdollahi, A.; Solanas, E.; Rijnders, G.; Catalan, G.

    2016-01-01

    Piezoelectricity and flexoelectricity are two independent but not incompatible forms of electromechanical response exhibited by nanoscale ferroelectrics. Here, we show that flexoelectricity can either enhance or suppress the piezoelectric response of the cantilever depending on the ferroelectric polarity and lead to a diode-like asymmetric (two-state) electromechanical response.Piezoelectricity and flexoelectricity are two independent but not incompatible forms of electromechanical response exhibited by nanoscale ferroelectrics. Here, we show that flexoelectricity can either enhance or suppress the piezoelectric response of the cantilever depending on the ferroelectric polarity and lead to a diode-like asymmetric (two-state) electromechanical response. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06514c

  16. 78 FR 15682 - Notification of Proposed Production Activity TTI, Inc.; Subzone 196A (Electromechanical and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-12

    ... production equipment. The components and materials sourced from abroad include: Rubber and plastic gaskets... Foreign-Trade Zones Board Notification of Proposed Production Activity TTI, Inc.; Subzone 196A (Electromechanical and Circuit Protection Devices Production/ Kitting); Fort Worth, TX TTI, Inc. (TTI), operator...

  17. Non-contact method for characterization of small size thermoelectric modules.

    PubMed

    Manno, Michael; Yang, Bao; Bar-Cohen, Avram

    2015-08-01

    Conventional techniques for characterization of thermoelectric performance require bringing measurement equipment into direct contact with the thermoelectric device, which is increasingly error prone as device size decreases. Therefore, the novel work presented here describes a non-contact technique, capable of accurately measuring the maximum ΔT and maximum heat pumping of mini to micro sized thin film thermoelectric coolers. The non-contact characterization method eliminates the measurement errors associated with using thermocouples and traditional heat flux sensors to test small samples and large heat fluxes. Using the non-contact approach, an infrared camera, rather than thermocouples, measures the temperature of the hot and cold sides of the device to determine the device ΔT and a laser is used to heat to the cold side of the thermoelectric module to characterize its heat pumping capacity. As a demonstration of the general applicability of the non-contact characterization technique, testing of a thin film thermoelectric module is presented and the results agree well with those published in the literature.

  18. Electromechanical properties of amorphous indium-gallium-zinc-oxide transistors structured with an island configuration on plastic

    NASA Astrophysics Data System (ADS)

    Park, Chang Bum; Na, Hyung Il; Yoo, Soon Sung; Park, Kwon-Shik

    2016-03-01

    A comparative study of the electromechanical properties was carried out on a low-temperature-processed amorphous indium-gallium-zinc-oxide thin-film transistor, particularly with regard to the structural design of the device under the stress accumulation of an outward bending surface. Shown herein is the reliable electromechanical integrity of island-structured devices against the mechanical strain at bending radii of mm order. The onset of crack strain also closely corresponded to the electrical failure of the stressed device. These results revealed that the island configuration on the bending surface effectively suppresses the stress accumulation on sheets composed of inorganic stacked layers in a uniaxial direction.

  19. Report on Non-Contact DC Electric Field Sensors

    SciTech Connect

    Miles, R; Bond, T; Meyer, G

    2009-06-16

    This document reports on methods used to measure DC electrostatic fields in the range of 100 to 4000 V/m using a non-contact method. The project for which this report is written requires this capability. Non-contact measurements of DC fields is complicated by the effect of the accumulation of random space-charges near the sensors which interfere with the measurement of the field-of-interest and consequently, many forms of field measurements are either limited to AC measurements or use oscillating devices to create pseudo-AC fields. The intent of this document is to report on methods discussed in the literature for non-contact measurement of DC fields. Electric field meters report either the electric field expressed in volts per distance or the voltage measured with respect to a ground reference. Common commercial applications for measuring static (DC) electric fields include measurement of surface charge on materials near electronic equipment to prevent arcing which can destroy sensitive electronic components, measurement of the potential for lightning to strike buildings or other exposed assets, measurement of the electric fields under power lines to investigate potential health risks from exposure to EM fields and measurement of fields emanating from the brain for brain diagnostic purposes. Companies that make electric field sensors include Trek (Medina, NY), MKS Instruments, Boltek, Campbell Systems, Mission Instruments, Monroe Electronics, AlphaLab, Inc. and others. In addition to commercial vendors, there are research activities continuing in the MEMS and optical arenas to make compact devices using the principles applied to the larger commercial sensors.

  20. Case study of piezoelectric flexible thin films in pulse excited electromechanical transducers

    NASA Astrophysics Data System (ADS)

    Salamon, Natalia; Gozdur, Roman; Turczyński, Marcin; Lisik, Zbigniew; Soupremanien, Ulrich; Ollier, Emmanuel; Monfray, Stéphane; Skotnicki, Thomas

    2014-08-01

    The paper presents the examination of modern flexible piezoelectric thin films made of PVDF (polyvinylidene difluoride) in terms of their application in electromechanical transducers, a brief overview of available piezoelectric materials and energy harvesting devices based on piezoelectric. In order to assess the usefulness of these films from the perspective of described devices, the energy efficiency coefficient determined under the pulse excitation conditions was taken into account. Normalized volumetric efficiency ratio allows to evaluate the commercially available flexible piezoelectric films.

  1. Electromechanical Properties of Bone Tissue.

    NASA Astrophysics Data System (ADS)

    Regimbal, Raymond L.

    demonstrated that the major inorganic and organic phases of bone are electromechanically coupled, a thermodynamic consideration of the data suggests that the nature of the bond is to preserve mineral and organic phase electroneutralities by participating in electrical double layer interactions. The results are discussed in terms of bone mechanical modeling, electrokinetic properties, aging, tissue-implant compatibility and the etiologies of bone pathologic conditions.

  2. Electromechanically active polymer transducers: research in Europe

    NASA Astrophysics Data System (ADS)

    Carpi, Federico; Graz, Ingrid; Jager, Edwin; Ladegaard Skov, Anne; Vidal, Frédéric

    2013-10-01

    Smart materials and structures based on electromechanically active polymers (EAPs) represent a fast growing and stimulating field of research and development. EAPs are materials capable of changing dimensions and/or shape in response to suitable electrical stimuli. They are commonly classified in two major families: ionic EAPs (activated by an electrically induced transport of ions and/or solvent) and electronic EAPs (activated by electrostatic forces). These polymers show interesting properties, such as sizable active strains and/or stresses in response to electrical driving, high mechanical flexibility, low density, structural simplicity, ease of processing and scalability, no acoustic noise and, in most cases, low costs. Since many of these characteristics can also describe natural muscle tissues from an engineering standpoint, it is not surprising that EAP transducers are sometimes also referred to as 'muscle-like smart materials' or 'artificial muscles'. They are used not only to generate motion, but also to sense or harvest energy from it. In particular, EAP electromechanical transducers are studied for applications that can benefit from their 'biomimetic' characteristics, with possible usages from the micro- to the macro-scale, spanning several disciplines, such as mechatronics, robotics, automation, biotechnology and biomedical engineering, haptics, fluidics, optics and acoustics. Currently, the EAP field is just undergoing its initial transition from academic research into commercialization, with companies starting to invest in this technology and the first products appearing on the market. This focus issue is intentionally aimed at gathering contributions from the most influential European groups working in the EAP field. In fact, today Europe hosts the broadest EAP community worldwide. The rapid expansion of the EAP field in Europe, where it historically has strong roots, has stimulated the creation of the 'European Scientific Network for Artificial

  3. Silicon Micropore based Electromechanical Transducer to Differentiate Tumor Cells

    NASA Astrophysics Data System (ADS)

    Ali, Waqas; Raza, Muhammad U.; Khanzada, Raja R.; Kim, Young-Tae; Iqbal, Samir M.

    2015-03-01

    Solid-state micropores have been used before to differentiate cancer cells from normal cells using size-based filtering. Tumor cells differ from normal ones not only in size but also in physical properties like elasticity, shape, motility etc. Tumor cells show different physical attributes depending on the stage and type of cancer. We report a micropore based electromechanical transducer that differentiated cancer cells based on their mechanophysical properties. The device was interfaced with a high-speed patch-clamp measurement system that biased the ionic solution across the silicon-based membrane. The bias resulted in the flow of ionic current. Electrical pulses were generated when cells passed through. Different cells depicted characteristic pulses. Translocation profiles of cells that were either small or were more elastic and flexible caused electrical pulses shorter in widths and amplitudes whereas cells with larger size or lesser elasticity/flexibility showed deeper and wider pulses. Three non-small cell lung cancer (NSCLC) cell lines NCI-H1155, A549 and NCI-H460 were successfully differentiated. NCI-H1155, due to their comparatively smaller size, were found quickest in translocating through. The solid-sate micropore based electromechanical transducer could process the whole blood sample of cancer patient without any pre-processing requirements and is ideal for point-of-care applications. Support Acknowledged from NSF through ECCS-1201878.

  4. Electromechanical properties of smart aggregate: theoretical modeling and experimental validation

    NASA Astrophysics Data System (ADS)

    Wang, Jianjun; Kong, Qingzhao; Shi, Zhifei; Song, Gangbing

    2016-09-01

    Smart aggregate (SA), as a piezoceramic-based multi-functional device, is formed by sandwiching two lead zirconate titanate (PZT) patches with copper shielding between a pair of solid-machined cylindrical marble blocks with epoxy. Previous researches have successfully demonstrated the capability and reliability of versatile SAs to monitor the structural health of concrete structures. However, the previous works concentrated mainly on the applications of SAs in structural health monitoring; no reasonable theoretical model of SAs was proposed. In this paper, electromechanical properties of SAs were investigated using a proposed theoretical model. Based on one dimensional linear theory of piezo-elasticity, the dynamic solutions of a SA subjected to an external harmonic voltage were solved. Further, the electric impedance of the SA was computed, and the resonance and anti-resonance frequencies were calculated based on derived equations. Numerical analysis was conducted to discuss the effects of the thickness of epoxy layer and the dimension of PZT patch on the fundamental resonance and anti-resonance frequencies as well as the corresponding electromechanical coupling factor. The dynamic solutions based on the proposed theoretical model were further experimentally verified with two SA samples. The fundamental resonance and anti-resonance frequencies of SAs show good agreements in both theoretical and experimental results. The presented analysis and results contribute to the overall understanding of SA properties and help to optimize the working frequencies of SAs in structural health monitoring of civil structures.

  5. Electromechanical cardioplasty using a wrapped elasto-conductive epicardial mesh.

    PubMed

    Park, Jinkyung; Choi, Suji; Janardhan, Ajit H; Lee, Se-Yeon; Raut, Samarth; Soares, Joao; Shin, Kwangsoo; Yang, Shixuan; Lee, Chungkeun; Kang, Ki-Woon; Cho, Hye Rim; Kim, Seok Joo; Seo, Pilseon; Hyun, Wonji; Jung, Sungmook; Lee, Hye-Jeong; Lee, Nohyun; Choi, Seung Hong; Sacks, Michael; Lu, Nanshu; Josephson, Mark E; Hyeon, Taeghwan; Kim, Dae-Hyeong; Hwang, Hye Jin

    2016-06-22

    Heart failure remains a major public health concern with a 5-year mortality rate higher than that of most cancers. Myocardial disease in heart failure is frequently accompanied by impairment of the specialized electrical conduction system and myocardium. We introduce an epicardial mesh made of electrically conductive and mechanically elastic material, to resemble the innate cardiac tissue and confer cardiac conduction system function, to enable electromechanical cardioplasty. Our epicardium-like substrate mechanically integrated with the heart and acted as a structural element of cardiac chambers. The epicardial device was designed with elastic properties nearly identical to the epicardial tissue itself and was able to detect electrical signals reliably on the moving rat heart without impeding diastolic function 8 weeks after induced myocardial infarction. Synchronized electrical stimulation over the ventricles by the epicardial mesh with the high conductivity of 11,210 S/cm shortened total ventricular activation time, reduced inherent wall stress, and improved several measures of systolic function including increases of 51% in fractional shortening, ~90% in radial strain, and 42% in contractility. The epicardial mesh was also capable of delivering an electrical shock to terminate a ventricular tachyarrhythmia in rodents. Electromechanical cardioplasty using an epicardial mesh is a new pathway toward reconstruction of the cardiac tissue and its specialized functions. PMID:27334261

  6. Standardization of noncontact 3D measurement

    NASA Astrophysics Data System (ADS)

    Takatsuji, Toshiyuki; Osawa, Sonko; Sato, Osamu

    2008-08-01

    As the global R&D competition is intensified, more speedy measurement instruments are required both in laboratories and production process. In machinery areas, while contact type coordinate measuring machines (CMM) have been widely used, noncontact type CMMs are growing its market share which are capable of measuring enormous number of points at once. Nevertheless, since no industrial standard concerning an accuracy test of noncontact CMMs exists, each manufacturer writes the accuracy of their product according to their own rules, and this situation gives confusion to customers. The working group ISO/TC 213/WG 10 is trying to make a new ISO standard which stipulates an accuracy test of noncontact CMMs. The concept and the situation of discussion of this new standard will be explained. In National Metrology Institute of Japan (NMIJ), we are collecting measurement data which serves as a technical background of the standards together with a consortium formed by users and manufactures. This activity will also be presented.

  7. Electromechanical Technology. Post Secondary Curriculum Guide.

    ERIC Educational Resources Information Center

    Butler, Raymond H.; And Others

    This curriculum guide provides a model for a postsecondary electromechanical technology program. It is divided into 10 sections. Section 1 overviews the philosophy, purpose, and goals for vocational education in Georgia. Contents of section 2 include a definition of the guide's purpose and program objective. Section 3 describes the occupational…

  8. Electromechanical flight control actuator, volume 3

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The design verification tests which were conducted on the electromechanical actuator are described. A description is also given of the power components tests which were conducted to aid in selecting the power transistors for use in the single-channel power electronics breadboard and the results of tests which were conducted on the power electronics breadboard.

  9. Noncontact Monitoring of Blood Oxygen Saturation Using Camera and Dual-Wavelength Imaging System.

    PubMed

    Shao, Dangdang; Liu, Chenbin; Tsow, Francis; Yang, Yuting; Du, Zijian; Iriya, Rafael; Yu, Hui; Tao, Nongjian

    2016-06-01

    We present a noncontact method to monitor blood oxygen saturation (SpO2). The method uses a CMOS camera with a trigger control to allow recording of photoplethysmography (PPG) signals alternatively at two particular wavelengths, and determines the SpO2 from the measured ratios of the pulsatile to the nonpulsatile components of the PPG signals at these wavelengths. The signal-to-noise ratio (SNR) of the SpO2 value depends on the choice of the wavelengths. We found that the combination of orange (λ = 611 nm) and near infrared (λ = 880 nm) provides the best SNR for the noncontact video-based detection method. This combination is different from that used in traditional contact-based SpO 2 measurement since the PPG signal strengths and camera quantum efficiencies at these wavelengths are more amenable to SpO2 measurement using a noncontact method. We also conducted a small pilot study to validate the noncontact method over an SpO2 range of 83%-98%. This study results are consistent with those measured using a reference contact SpO2 device ( r = 0.936, ). The presented method is particularly suitable for tracking one's health and wellness at home under free-living conditions, and for those who cannot use traditional contact-based PPG devices. PMID:26415199

  10. Non-Contact Heart Rate Monitoring Using Lab Color Space.

    PubMed

    Rahman, Hamidur; Ahmed, Mobyen Uddin; Begum, Shahina

    2016-01-01

    Research progressing during the last decade focuses more on non-contact based systems to monitor Heart Rate (HR) which are simple, low-cost and comfortable to use. Most of the non-contact based systems are using RGB videos which is suitable for lab environment. However, it needs to progress considerably before they can be applied in real life applications. As luminance (light) has significance contribution on RGB videos HR monitoring using RGB videos are not efficient enough in real life applications in outdoor environment. This paper presents a HR monitoring method using Lab color facial video captured by a webcam of a laptop computer. Lab color space is device independent and HR can be extracted through facial skin color variation caused by blood circulation considering variable environmental light. Here, three different signal processing methods i.e., Fast Fourier Transform (FFT), Independent Component Analysis (ICA) and Principal Component Analysis (PCA) have been applied on the color channels in video recordings and blood volume pulse (BVP) has been extracted from the facial regions. In this study, HR is subsequently quantified and compare with a reference measurement. The result shows that high degrees of accuracy have been achieved compared to the reference measurements. Thus, this technology has significant potential for advancing personal health care, telemedicine and many real life applications such as driver monitoring. PMID:27225552

  11. Low tension graphene drums for electromechanical pressure sensing

    NASA Astrophysics Data System (ADS)

    Patel, Raj N.; Mathew, John P.; Borah, Abhinandan; Deshmukh, Mandar M.

    2016-03-01

    We present a process to fabricate electromechanical pressure sensors using multilayer graphene in a sealed drum geometry. The drum resonators are fabricated on insulating sapphire substrates with a local back gate for direct radio frequency ({\\text{}}{{rf}}) actuation and detection of the mechanical modes. Using this scheme, we show the detection and electrostatic tuning of multiple resonant modes of the membrane up to 200 MHz. The geometry of the device also helps in attaining low tensile stress in the membrane, thereby giving high gate tunability (∼1 MHz/V) of the resonator modes. We study the resonant frequency shifts in the presence of helium gas and demonstrate a sensing capability of 1 Torr pressure in a cryogenic environment.

  12. Development of a Tunable Electromechanical Acoustic Liner for Engine Nacelles

    NASA Technical Reports Server (NTRS)

    Liu, Fei; Sheplak, Mark; Cattafesta, Louis N., III

    2007-01-01

    provides the information for a designer that shows how design trade-offs can be used to satisfy specific design requirements. The optimization design of the EMHR with inductive loads aims at optimal tuning of these three resonant fiequencies. The results indicate that it is possible to keep the acoustic reactance of the resonator close to a constant over a given frequency range. An effort to mimic the second layer of the NASA 2DOF liner using a piezoelectric composite diaphragm has been made. The optimal acoustic reactance of the second layer of the NASA 2DOF liner is achieved using a thin PVDF composite diaphragm, but matching the acoustic resistance requires further investigation. Acoustic energy harvesting is achieved by connecting the EMHR to an energy reclamation circuit that converts the ac voltage signal across the piezoceramic to a conditioned dc signal. Energy harvesting experiment yields 16 m W continuous power for an incident SPL of 153 dB. Such a level is sufficient to power a variety of low power electronic devices. Finally, technology transfer has been achieved by converting the original NASA ZKTL FORTRAN code to a MATLAB code while incorporating the models of the EMHR. Initial studies indicate that the EMHR is a promising technology that may enable lowpower, light weight, tunable engine nacelle liners. This technology, however, is very immature, and additional developments are required. Recommendations for future work include testing of sample EMHR liner designs in NASA Langley s normal incidence dual-waveguide and the grazing-incidence flow facility to evaluating both the impedance characteristics as well as the energy reclamation abilities. Additional design work is required for more complex tuning circuits with greater performance. Poor electromechanical coupling limited the electromechanical tuning capabilities of the proof of concept EMHR. Different materials than those studies and perhaps novel composite material systems may dramatically improvehe

  13. Electromechanical sensing of substrate charge hidden under atomic 2D crystals.

    PubMed

    Kay, Nicholas D; Robinson, Benjamin J; Fal'ko, Vladimir I; Novoselov, Konstantin S; Kolosov, Oleg V

    2014-06-11

    The functionality of graphene and other two-dimensional materials in electronic devices is highly influenced by the film-substrate charge transfer affecting local carrier density. We demonstrate that charges buried under the few layer graphene on/in the insulating substrate can be detected using electromechanical actuation of the conductive atomically thin layers, allowing measurements of areal density of film-substrate transferred charges under few layer graphene and MoS2 suspended films.

  14. Microwave electromechanical resonator consisting of clamped carbon nanotubes in an abacus arrangement

    NASA Astrophysics Data System (ADS)

    Peng, H. B.; Chang, C. W.; Aloni, S.; Yuzvinsky, T. D.; Zettl, A.

    2007-07-01

    We describe nanoscale electromechanical resonators capable of operating in ambient-pressure air at room temperature with unprecedented fundamental resonance frequency of ˜4GHz . The devices are created from suspended carbon nanotubes loaded abacus style with inertial metal clamps, yielding short effective beam lengths. We examine the energy dissipation in the system due to air damping and contact loss. Such nanoabacus resonators open windows for immediate practical microwave frequency nanoelectromechanical system applications.

  15. Passive magnetic bearings for vehicular electromechanical batteries

    SciTech Connect

    Post, R

    1996-03-01

    This report describes the design of a passive magnetic bearing system to be used in electromechanical batteries (flywheel energy storage modules) suitable for vehicular use. One or two such EMB modules might, for example, be employed in a hybrid-electric automobile, providing efficient means for power peaking, i.e., for handling acceleration and regenerative braking power demands at high power levels. The bearing design described herein will be based on a ''dual-mode'' operating regime.

  16. Electromechanical flight control actuator, volume 2

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Schematic diagrams are given for both the four-channel electromechanical actuator and the single-channel power electronics breadboard. Detailed design data is also given on the gears used in the differential gearbox and a copy of the operations manual for the system is included. Performance test results are given for the EMA motor and its current source indicator, the drive control electronics, and the overall system. The power converter waveform test results are also summarized.

  17. Large scale electromechanical transistor with application in mass sensing

    SciTech Connect

    Jin, Leisheng; Li, Lijie

    2014-12-07

    Nanomechanical transistor (NMT) has evolved from the single electron transistor, a device that operates by shuttling electrons with a self-excited central conductor. The unfavoured aspects of the NMT are the complexity of the fabrication process and its signal processing unit, which could potentially be overcome by designing much larger devices. This paper reports a new design of large scale electromechanical transistor (LSEMT), still taking advantage of the principle of shuttling electrons. However, because of the large size, nonlinear electrostatic forces induced by the transistor itself are not sufficient to drive the mechanical member into vibration—an external force has to be used. In this paper, a LSEMT device is modelled, and its new application in mass sensing is postulated using two coupled mechanical cantilevers, with one of them being embedded in the transistor. The sensor is capable of detecting added mass using the eigenstate shifts method by reading the change of electrical current from the transistor, which has much higher sensitivity than conventional eigenfrequency shift approach used in classical cantilever based mass sensors. Numerical simulations are conducted to investigate the performance of the mass sensor.

  18. Electromechanical interaction on the deformation behavior of metallic materials

    NASA Astrophysics Data System (ADS)

    Zhao, Guangfeng

    Metallic materials play important roles in providing electrical, thermal, and mechanical functions in electronic devices and systems. The understanding of the electrical-thermal-mechanical interaction caused by the passage of electric current with high density is important to improve the performance and reliability of electronic assembly and packaging. The electromechanical interaction on the deformation behavior of copper and tin is studied in this work. The electromechanical response of Cu strips was studied by passing a DC electric current. The electric resistance linearly increased with time before the occurrence of electric fusing. The electrothermal interaction led to the buckling of the Cu strips with the maximum deflection increasing with the increase of the electric current density. The total strain was found to be proportional to the square of the electric current density. A power law relation was used to describe the dependence of the time-to-fusing on the electric current density. Using the nanoindentation technique, the effect of electric current on the indentation deformation of copper and tin was studied. The reduced contact modulus of copper and tin decreased with increasing the electric current density. With the passage of a DC electric current, the indentation hardness of copper increased slightly with increasing electric current density. With the passage of an AC electric current, the indentation hardness of copper decreased with increasing the indentation deformation. With the passage of a DC electric current, the indentation hardness of tin decreased with increasing the indentation load, showing the normal indentation size effect. Both the limit of infinite depth and the characteristic length were dependent on the electric current density. Using the tensile creep technique, the creep deformation of pure tin was studied with the passage of a DC electric current. The steady state creep rate increased with the increase in temperature, tensile

  19. As-Grown Gallium Nitride Nanowire Electromechanical Resonators

    NASA Astrophysics Data System (ADS)

    Montague, Joshua R.

    Technological development in recent years has led to a ubiquity of micro- and nano-scale electromechanical devices. Sensors for monitoring temperature, pressure, mass, etc., are now found in nearly all electronic devices at both the industrial and consumer levels. As has been true for integrated circuit electronics, these electromechanical devices have continued to be scaled down in size. For many nanometer-scale structures with large surface-to-volume ratio, dissipation (energy loss) becomes prohibitively large causing a decreasing sensitivity with decreasing sensor size. In this work, gallium nitride (GaN) nanowires are investigated as singly-clamped (cantilever) mechanical resonators with typical mechanical quality factors, Q (equal to the ratio of resonance frequency to peak full-width-at-half-maximum-power) and resonance frequencies, respectively, at or above 30,000, and near 1 MHz. These Q values---in vacuum at room temperature---indicate very low levels of dissipation; they are essentially the same as those for bulk quartz crystal resonators that form the basis of simple clocks and mass sensors. The GaN nanowires have lengths and diameters, respectively, of approximately 15 micrometers and hundreds of nanometers. As-grown GaN nanowire Q values are larger than other similarly-sized, bottom-up, cantilever resonators and this property makes them very attractive for use as resonant sensors. We demonstrate the capability of detecting sub-monolayer levels of atomic layer deposited (ALD) films, and the robust nature of the GaN nanowires structure that allows for their 'reuse' after removal of such layers. In addition to electron microscope-based measurement techniques, we demonstrate the successful capacitive detection of a single nanowire using microwave homodyne reflectometry. This technique is then extended to allow for simultaneous measurements of large ensembles of GaN nanowires on a single sample, providing statistical information about the distribution of

  20. Non-Contact Gaging with Laser Probe

    SciTech Connect

    Clinesmith, Mike

    2009-03-20

    A gage has been constructed using conventional (high end) components for the application of measuring fragile syntactic foam parts in a non-contact mode. Success with this approach has been achieved through a novel method of transferring (mapping) high accuracy local measurements of a coated aluminum master, taken on a Leitz Coordinate Measurement Machine (CMM), to the gage software system. The mapped data is then associated with local voltage readings from two (inner and outer) laser triangulating probes. This couples discreet laser probe offset and linearity characteristics to the measured master geometry. The gage software compares real part measured data against the master data to provide non-contact part inspection that results in a high accuracy and low uncertainty performance. Uncertainty from the part surface becomes the prevailing contributor to the gaging process. The gaging process provides a high speed, hands off measurement with nearly zero impedance.

  1. High voltage DC switchgear development for multi-kW space power system: Aerospace technology development of three types of solid state power controllers for 200-1100VDC with current ratings of 25, 50, and 80 amperes with one type utilizing an electromechanical device

    NASA Technical Reports Server (NTRS)

    Billings, W. W.

    1981-01-01

    Three types of solid state power controllers (SSPC's) for high voltage, high power DC system applications were developed. The first type utilizes a SCR power switch. The second type employes an electromechanical power switch element with solid state commutation. The third type utilizes a transistor power switch. Significant accomplishments include high operating efficiencies, fault clearing, high/low temperature performance and vacuum operation.

  2. Orientation Dependence of Electromechanical Characteristics of Defect-free InAs Nanowires.

    PubMed

    Zheng, Kun; Zhang, Zhi; Hu, Yibin; Chen, Pingping; Lu, Wei; Drennan, John; Han, Xiaodong; Zou, Jin

    2016-03-01

    Understanding the electrical properties of defect-free nanowires with different structures and their responses under deformation are essential for design and applications of nanodevices and strain engineering. In this study, defect-free zinc-blende- and wurtzite-structured InAs nanowires were grown using molecular beam epitaxy, and individual nanowires with different structures and orientations were carefully selected and their electrical properties and electromechanical responses were investigated using an electrical probing system inside a transmission electron microscope. Through our careful experimental design and detailed analyses, we uncovered several extraordinary physical phenomena, such as the electromechanical characteristics are dominated by the nanowire orientation, rather than its crystal structure. Our results provide critical insights into different responses induced by deformation of InAs with different structures, which is important for nanowire-based devices. PMID:26837494

  3. Noncontact depth-resolved micro-scale corneal elastography

    NASA Astrophysics Data System (ADS)

    Wang, Shang; Larin, Kirill V.

    2015-03-01

    Noninvasive high-resolution depth-resolved measurement of corneal biomechanics is of great clinical significance for improving the diagnosis and optimizing the treatment of various degenerated ocular diseases. Here, we report a micro-scale optical coherence elastography (OCE) method that enables noncontact assessment of the depthwise elasticity distribution in the cornea. The OCE system combines a focused air-puff device with phase-sensitive optical coherence tomography (OCT). Low-pressure short-duration air stream is used to load the cornea with the localized displacement at micron level. The phase-resolved OCT detection with nano-scale sensitivity probes the induced corneal deformation at various locations within a scanning line, providing the ultra-fast imaging of the corneal lamb wave propagation. With spectral analysis, the amplitude spectra and the phase spectra are available for the estimation of the frequency range of the lamb wave and the quantification of the wave propagation, respectively. Curved propagation paths following the top and bottom corneal boundaries are selected inside the cornea for measuring the phase velocity of the lamb wave at the major frequency components over the whole depths. Our pilot experiments on ex vivo rabbit eyes indicate the distinct stiffness of different layers in the cornea, including the epithelium, the anterior stroma, the posterior stroma, and the innermost region, which demonstrates the feasibility of this micro-scale OCE method for noncontact depth-resolved corneal elastography. Also, the quantification of the lamb wave dispersion in the cornea could lead to the measurement of the elastic modulus, suggesting the potential of this method for quantitative monitoring of the corneal biomechanics.

  4. Continuous wave terahertz spectrometer as a noncontact thickness measuring device.

    PubMed

    Wilk, Rafał; Breitfeld, Falk; Mikulics, Martin; Koch, Martin

    2008-06-01

    We present a low cost terahertz (THz) spectrometer with coherent detection based on two simple and robust dipole antennas driven by two laser diodes. The spectrometer covers frequencies up to 1 THz, with a peak signal-to-noise ratio exceeding 40 dB for a lock-in integration time of 30 ms. We demonstrate that the thickness profile of a sample can be reconstructed from an acquired THz image. PMID:18516122

  5. 25 CFR 502.8 - Electronic or electromechanical facsimile.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... facsimile means a game played in an electronic or electromechanical format that replicates a game of chance by incorporating all of the characteristics of the game, except when, for bingo, lotto, and other games similar to bingo, the electronic or electromechanical format broadens participation by...

  6. 25 CFR 502.8 - Electronic or electromechanical facsimile.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... facsimile means a game played in an electronic or electromechanical format that replicates a game of chance by incorporating all of the characteristics of the game, except when, for bingo, lotto, and other games similar to bingo, the electronic or electromechanical format broadens participation by...

  7. 25 CFR 502.8 - Electronic or electromechanical facsimile.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... facsimile means a game played in an electronic or electromechanical format that replicates a game of chance by incorporating all of the characteristics of the game, except when, for bingo, lotto, and other games similar to bingo, the electronic or electromechanical format broadens participation by...

  8. 25 CFR 502.8 - Electronic or electromechanical facsimile.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... facsimile means a game played in an electronic or electromechanical format that replicates a game of chance by incorporating all of the characteristics of the game, except when, for bingo, lotto, and other games similar to bingo, the electronic or electromechanical format broadens participation by...

  9. 25 CFR 502.8 - Electronic or electromechanical facsimile.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... facsimile means a game played in an electronic or electromechanical format that replicates a game of chance by incorporating all of the characteristics of the game, except when, for bingo, lotto, and other games similar to bingo, the electronic or electromechanical format broadens participation by...

  10. Visualizing Nano-Electromechanics by Vector Piezoresponse Force Microscopy

    SciTech Connect

    Rodriguez, Brian J; Jesse, Stephen; Baddorf, Arthur P; Kalinin, Sergei V; Gruverman, A.

    2005-01-01

    This is a detailed examination of the electro-mechanical and elastic coupling that occurs in the scanning probe microscopy of electro-active materials. This research is useful to detecting, imaging and understanding the orientation of nanoscale electromechanical anisotropies in material. This method has been applied to piezo electric and ferro electric thin films as well as biological samples.

  11. Solid state devices

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Solid State Device research program is directed toward developing innovative devices for space remote and in-situ sensing, and for data processing. Innovative devices can result from the standard structures in innovative materials such as low and high temperature superconductors, strained layer superlattices, or diamond films. Innovative devices can also result from innovative structures achieved using electron tunneling or nanolithography in standard materials. A final step is to use both innovative structures and innovative materials. A new area of emphasis is the miniaturization of sensors and instruments molded by using the techniques of electronic device fabrication to micromachine silicon into micromechanical and electromechanical sensors and actuators.

  12. Noncontact orientation of objects in three-dimensional space using magnetic levitation.

    PubMed

    Subramaniam, Anand Bala; Yang, Dian; Yu, Hai-Dong; Nemiroski, Alex; Tricard, Simon; Ellerbee, Audrey K; Soh, Siowling; Whitesides, George M

    2014-09-01

    This paper describes several noncontact methods of orienting objects in 3D space using Magnetic Levitation (MagLev). The methods use two permanent magnets arranged coaxially with like poles facing and a container containing a paramagnetic liquid in which the objects are suspended. Absent external forcing, objects levitating in the device adopt predictable static orientations; the orientation depends on the shape and distribution of mass within the objects. The orientation of objects of uniform density in the MagLev device shows a sharp geometry-dependent transition: an analytical theory rationalizes this transition and predicts the orientation of objects in the MagLev device. Manipulation of the orientation of the levitating objects in space is achieved in two ways: (i) by rotating and/or translating the MagLev device while the objects are suspended in the paramagnetic solution between the magnets; (ii) by moving a small external magnet close to the levitating objects while keeping the device stationary. Unlike mechanical agitation or robotic selection, orienting using MagLev is possible for objects having a range of different physical characteristics (e.g., different shapes, sizes, and mechanical properties from hard polymers to gels and fluids). MagLev thus has the potential to be useful for sorting and positioning components in 3D space, orienting objects for assembly, constructing noncontact devices, and assembling objects composed of soft materials such as hydrogels, elastomers, and jammed granular media. PMID:25157136

  13. Noncontact orientation of objects in three-dimensional space using magnetic levitation

    PubMed Central

    Subramaniam, Anand Bala; Yang, Dian; Yu, Hai-Dong; Nemiroski, Alex; Tricard, Simon; Ellerbee, Audrey K.; Soh, Siowling; Whitesides, George M.

    2014-01-01

    This paper describes several noncontact methods of orienting objects in 3D space using Magnetic Levitation (MagLev). The methods use two permanent magnets arranged coaxially with like poles facing and a container containing a paramagnetic liquid in which the objects are suspended. Absent external forcing, objects levitating in the device adopt predictable static orientations; the orientation depends on the shape and distribution of mass within the objects. The orientation of objects of uniform density in the MagLev device shows a sharp geometry-dependent transition: an analytical theory rationalizes this transition and predicts the orientation of objects in the MagLev device. Manipulation of the orientation of the levitating objects in space is achieved in two ways: (i) by rotating and/or translating the MagLev device while the objects are suspended in the paramagnetic solution between the magnets; (ii) by moving a small external magnet close to the levitating objects while keeping the device stationary. Unlike mechanical agitation or robotic selection, orienting using MagLev is possible for objects having a range of different physical characteristics (e.g., different shapes, sizes, and mechanical properties from hard polymers to gels and fluids). MagLev thus has the potential to be useful for sorting and positioning components in 3D space, orienting objects for assembly, constructing noncontact devices, and assembling objects composed of soft materials such as hydrogels, elastomers, and jammed granular media. PMID:25157136

  14. Electromechanics and Electrical Breakdown of Particulate Layers

    NASA Astrophysics Data System (ADS)

    Moslehi, Bizhan G. R.

    A comprehensive theory of the electromechanics and electrical breakdown of a current-carrying particulate layer is developed, which takes into account its inhomogeneous nature and mode of compaction. The theory treates the general case of combined surface and volume conduction and takes account of self-compression of the layer due to electrical forces. The electromechanical theory predicts the existence of a remarkably large electrical cohesive stress in the layer due to a strong field enhancement in and around the contact regions. Furthermore, it shows a decrease in the apparent resistivity of the layer with increasing electric field as a result of self-compression. The analysis of electrical breakdown of current -carrying particulate layer predicts the onset of breakdown of the layer in the form of intermittent microsparks in the gap between the contacting particles when the electric field at the contact or in the surrounding gap exceeds the threshold breakdown value. An analysis of the behavior of the layer after breakdown in terms of a simplified equivalent lumped circuit predicts increases of sparking frequency and average current as the applied average field exceeds the threshold average field for the onset of breakdown. The results of measurements on layers of glass beads and fly-ash in a standard resistivity cell are in good agreement with the theoretical predictions for the field-dependent resistivity characteristics. The work has particular significance for electrostatic precipitation and addresses the phenomenon of backdischarge and the questions of the retention, rapping, and reentrainment of precipitation ash layers.

  15. Dynamic analysis of noncontacting face seals

    NASA Technical Reports Server (NTRS)

    Etsion, I.

    1980-01-01

    The dynamic behavior of a noncontacting coned face seal is analyzed taking into account various design parameters and operating conditions. The primary seal ring motion is expressed by a set of nonlinear equations for three degrees of freedom. These equations, which are solved numerically, allow identification of two dimensionless groups of parameters that affect the seal dynamic behavior. Stability maps for various seals are presented. These maps contain a stable-to-unstable transition region in which the ring wobbles at half the shaft frequency. The effect of various parameters on seal stability is discussed and an empirical expression for critical stability is offered.

  16. Non-contact temperature measurement requirements

    NASA Technical Reports Server (NTRS)

    Higgins, D. B.; Witherow, W. K.

    1989-01-01

    The Marshall Space Flight Center is involved with levitation experiments for Spacelab, Space Station, and drop tube/tower operations. These experiments have temperature measurement requirements, that of course must be non-contact in nature. The experiment modules involved are the Acoustic Levitator Furnace (ALF), and the Modular Electromagnetic Levitator (MEL). User requirements of the ALF and drop tube are presented. The center also has temperature measurement needs that are not microgravity experiment oriented, but rather are related to the propulsion system for the STS. This requirement will also be discussed.

  17. Precision non-contact polishing tool

    DOEpatents

    Taylor, John S.

    1997-01-01

    A non-contact polishing tool that combines two orthogonal slurry flow geometries to provide flexibility in altering the shape of the removal footprint. By varying the relative contributions of the two flow geometries, the footprint shape can be varied between the characteristic shapes corresponding to the two independent flow regimes. In addition, the tool can include a pressure activated means by which the shape of the brim of the tool can be varied. The tool can be utilized in various applications, such as x-ray optical surfaces, x-ray lithography, lenses, etc., where stringent shape and finish tolerances are required.

  18. Precision non-contact polishing tool

    DOEpatents

    Taylor, J.S.

    1997-01-07

    A non-contact polishing tool is disclosed that combines two orthogonal slurry flow geometries to provide flexibility in altering the shape of the removal footprint. By varying the relative contributions of the two flow geometries, the footprint shape can be varied between the characteristic shapes corresponding to the two independent flow regimes. In addition, the tool can include a pressure activated means by which the shape of the brim of the tool can be varied. The tool can be utilized in various applications, such as x-ray optical surfaces, x-ray lithography, lenses, etc., where stringent shape and finish tolerances are required. 5 figs.

  19. Self-acting geometry for noncontact seals

    NASA Technical Reports Server (NTRS)

    Allen, G. P.

    1981-01-01

    Performance ot two self acting seal designs for a liquid oxygen (LOX) turbopump was predicted over ranges of pressure differential and speed. Predictions were compared with test results. Performance of a radial face seal for LOX was predicted up to 448 N/cu cm and 147 m/sec. Performance of a segmented circumferential seal for helium was predicted up to 69 N/cu cm and 189 m/sec. Results confirmed predictions of noncontact operation. Qualitative agreement between test and analysis was found. The LOX face seal evidently operated with mostly liquid in the self acting geometry and mostly gas across the dam.

  20. A universal noncontact flowmeter for liquids

    NASA Astrophysics Data System (ADS)

    Wegfrass, André; Diethold, Christian; Werner, Michael; Fröhlich, Thomas; Halbedel, Bernd; Hilbrunner, Falko; Resagk, Christian; Thess, André

    2012-05-01

    Lorentz force velocimetry (LFV) is a noncontact electromagnetic flow measurement technique for liquid metals that is currently used in fundamental research and metallurgy. Up to now, the application of LFV was limited to the narrow class of liquids whose electrical conductivity is of the order 106 S/m. Here, we demonstrate that LFV can be applied to liquids with conductivities up to six orders of magnitude smaller than in liquid metals. We further argue that this range can be extended to 10-3 S/m under industrial and to 10-6 S/m under laboratory conditions making LFV applicable to most liquids of practical interest.

  1. Multi-reflective acoustic wave device

    DOEpatents

    Andle, Jeffrey C.

    2006-02-21

    An acoustic wave device, which utilizes multiple localized reflections of acoustic wave for achieving an infinite impulse response while maintaining high tolerance for dampening effects, is disclosed. The device utilized a plurality of electromechanically significant electrodes disposed on most of the active surface. A plurality of sensors utilizing the disclosed acoustic wave mode device are also described.

  2. MEMS device for spacecraft thermal control applications

    NASA Technical Reports Server (NTRS)

    Swanson, Theordore D. (Inventor)

    2003-01-01

    A micro-electromechanical device that comprises miniaturized mechanical louvers, referred to as Micro Electro-Mechanical Systems (MEMS) louvers are employed to achieve a thermal control function for spacecraft and instruments. The MEMS louvers are another form of a variable emittance control coating and employ micro-electromechanical technology. In a function similar to traditional, macroscopic thermal louvers, the MEMS louvers of the present invention change the emissivity of a surface. With the MEMS louvers, as with the traditional macroscopic louvers, a mechanical vane or window is opened and closed to allow an alterable radiative view to space.

  3. The Annular Momentum Control Device (AMCD)

    NASA Technical Reports Server (NTRS)

    Anderson, W. W.; Groom, N. J.

    1975-01-01

    An annular momentum control device consisting principally of a spinning rim, a set of noncontacting magnetic bearings for supporting the rim, a noncontacting electric motor for driving the rim, and, for some applications, one or more gimbals is described. The device is intended for applications where requirements for control torque and momentum storage exist. Hardware requirements and potential unit configurations are discussed. Theoretical considerations for the passive use of the device are discussed. Potential applications of the device in other than passive configurations for the attitude control, stabilization, and maneuvering of spacecraft are reported.

  4. The effect of carbon nanofillers on the performance of electromechanical polyaniline-based composite actuators

    NASA Astrophysics Data System (ADS)

    García-Gallegos, J. C.; Martín-Gullón, I.; Conesa, J. A.; Vega-Cantú, Y. I.; Rodríguez-Macías, F. J.

    2016-01-01

    Different types of crystalline carbon nanomaterials were used to reinforce polyaniline for use in electromechanical bilayer bending actuators. The objective is to analyze how the different graphitic structures of the nanocarbons affect and improve the in situ polymerized polyaniline composites and their subsequent actuator behavior. The nanocarbons investigated were multiwalled carbon nanotubes, nitrogen-doped carbon nanotubes, helical-ribbon carbon nanofibers and graphene oxide, each one presenting different shape and structural characteristics. Films of nanocarbon-PAni composite were tested in a liquid electrolyte cell system. Experimental design was used to select the type of nanocarbon filler and composite loadings, and yielded a good balance of electromechanical properties. Raman spectroscopy suggests good interaction between PAni and the nanocarbon fillers. Electron microscopy showed that graphene oxide dispersed the best, followed by multiwall carbon nanotubes, while nitrogen-doped nanotube composites showed dispersion problems and thus poor performance. Multiwall carbon nanotube composite actuators showed the best performance based on the combination of bending angle, bending velocity and maximum working cycles, while graphene oxide attained similarly good performance due to its best dispersion. This parallel testing of a broad set of nanocarbon fillers on PAni-composite actuators is unprecedented to the best of our knowledge and shows that the type and properties of the carbon nanomaterial are critical to the performance of electromechanical devices with other conditions remaining equal.

  5. The effect of carbon nanofillers on the performance of electromechanical polyaniline-based composite actuators.

    PubMed

    García-Gallegos, J C; Martín-Gullón, I; Conesa, J A; Vega-Cantú, Y I; Rodríguez-Macías, F J

    2016-01-01

    Different types of crystalline carbon nanomaterials were used to reinforce polyaniline for use in electromechanical bilayer bending actuators. The objective is to analyze how the different graphitic structures of the nanocarbons affect and improve the in situ polymerized polyaniline composites and their subsequent actuator behavior. The nanocarbons investigated were multiwalled carbon nanotubes, nitrogen-doped carbon nanotubes, helical-ribbon carbon nanofibers and graphene oxide, each one presenting different shape and structural characteristics. Films of nanocarbon-PAni composite were tested in a liquid electrolyte cell system. Experimental design was used to select the type of nanocarbon filler and composite loadings, and yielded a good balance of electromechanical properties. Raman spectroscopy suggests good interaction between PAni and the nanocarbon fillers. Electron microscopy showed that graphene oxide dispersed the best, followed by multiwall carbon nanotubes, while nitrogen-doped nanotube composites showed dispersion problems and thus poor performance. Multiwall carbon nanotube composite actuators showed the best performance based on the combination of bending angle, bending velocity and maximum working cycles, while graphene oxide attained similarly good performance due to its best dispersion. This parallel testing of a broad set of nanocarbon fillers on PAni-composite actuators is unprecedented to the best of our knowledge and shows that the type and properties of the carbon nanomaterial are critical to the performance of electromechanical devices with other conditions remaining equal. PMID:26595669

  6. Nano-electromechanical oscillators (NEMOs) for RF technologies.

    SciTech Connect

    Wendt, Joel Robert; Czaplewski, David A.; Gibson, John Murray; Webster, James R.; Carton, Andrew James; Keeler, Bianca Elizabeth Nelson; Carr, Dustin Wade; Friedmann, Thomas Aquinas; Tallant, David Robert; Boyce, Brad Lee; Sullivan, John Patrick; Dyck, Christopher William; Chen, Xidong

    2004-12-01

    Nano-electromechanical oscillators (NEMOs), capacitively-coupled radio frequency (RF) MEMS switches incorporating dissipative dielectrics, new processing technologies for tetrahedral amorphous carbon (ta-C) films, and scientific understanding of dissipation mechanisms in small mechanical structures were developed in this project. NEMOs are defined as mechanical oscillators with critical dimensions of 50 nm or less and resonance frequencies approaching 1 GHz. Target applications for these devices include simple, inexpensive clocks in electrical circuits, passive RF electrical filters, or platforms for sensor arrays. Ta-C NEMO arrays were used to demonstrate a novel optomechanical structure that shows remarkable sensitivity to small displacements (better than 160 fm/Hz {sup 1/2}) and suitability as an extremely sensitive accelerometer. The RF MEMS capacitively-coupled switches used ta-C as a dissipative dielectric. The devices showed a unipolar switching response to a unipolar stimulus, indicating the absence of significant dielectric charging, which has historically been the major reliability issue with these switches. This technology is promising for the development of reliable, low-power RF switches. An excimer laser annealing process was developed that permits full in-plane stress relaxation in ta-C films in air under ambient conditions, permitting the application of stress-reduced ta-C films in areas where low thermal budget is required, e.g. MEMS integration with pre-existing CMOS electronics. Studies of mechanical dissipation in micro- and nano-scale ta-C mechanical oscillators at room temperature revealed that mechanical losses are limited by dissipation associated with mechanical relaxation in a broad spectrum of defects with activation energies for mechanical relaxation ranging from 0.35 eV to over 0.55 eV. This work has established a foundation for the creation of devices based on nanomechanical structures, and outstanding critical research areas that need

  7. Electromechanical transducer for acoustic telemetry system

    DOEpatents

    Drumheller, Douglas S.

    1993-01-01

    An improved electromechanical transducer is provided for use in an acoustic telemetry system. The transducer of this invention comprises a stack of ferroelectric ceramic disks interleaved with a plurality of spaced electrodes which are used to electrically pole the ceramic disks. The ceramic stack is housed in a metal tubular drill collar segment. The electrodes are preferably alternatively connected to ground potential and driving potential. This alternating connection of electrodes to ground and driving potential subjects each disk to an equal electric field; and the direction of the field alternates to match the alternating direction of polarization of the ceramic disks. Preferably, a thin metal foil is sandwiched between electrodes to facilitate the electrical connection. Alternatively, a thicker metal spacer plate is selectively used in place of the metal foil in order to promote thermal cooling of the ceramic stack.

  8. Electromechanical transducer for acoustic telemetry system

    DOEpatents

    Drumheller, D.S.

    1993-06-22

    An improved electromechanical transducer is provided for use in an acoustic telemetry system. The transducer of this invention comprises a stack of ferroelectric ceramic disks interleaved with a plurality of spaced electrodes which are used to electrically pole the ceramic disks. The ceramic stack is housed in a metal tubular drill collar segment. The electrodes are preferably alternatively connected to ground potential and driving potential. This alternating connection of electrodes to ground and driving potential subjects each disk to an equal electric field; and the direction of the field alternates to match the alternating direction of polarization of the ceramic disks. Preferably, a thin metal foil is sandwiched between electrodes to facilitate the electrical connection. Alternatively, a thicker metal spacer plate is selectively used in place of the metal foil in order to promote thermal cooling of the ceramic stack.

  9. Electromechanical actuator for thrust vector control

    NASA Astrophysics Data System (ADS)

    Zubkow, Zygmunt

    Attention is given to the development and testing of electromechanical actuator (EMA) systems for use in first- and second-stage thrust vector control of rocket engines. An overview of the test program is also presented. Designs for both first- and second-stage actuators employ redundant dc brushless, three-phase rare-earth permanent magnet motors. The first-stage actuator is about 28 hp per motor and uses a roller screw. Second-stage thrust vector control is implemented with a much smaller actuator of about 1 hp per motor. This actuator uses a gear drive with a recycling ball screw mechanism. An operational EMA is presented. This 6.5-in. actuator is capable of a stall force of 1350 pounds per motor and a frequency response of about 5 HZ.

  10. Tunable electromechanical actuation in silicone dielectric film

    NASA Astrophysics Data System (ADS)

    Lamberti, Andrea; Di Donato, Marco; Chiappone, Annalisa; Giorgis, Fabrizio; Canavese, Giancarlo

    2014-10-01

    Dielectric elastomer actuator films were fabricated on transparent conductive electrode using bi-component poly(dimethyl)siloxane (PDMS). PDMS is a well-known material in microfluidics and soft lithography for biomedical applications, being easy to process, low cost, biocompatible and transparent. Moreover its mechanical properties can be easily tuned by varying the mixing ratio between the oligomer base and the crosslinking agent. In this work we investigate the chemical composition and the electromechanical properties of PDMS thin film verifying for the first time the tuneable actuation response by simply modifying the amount of the curing agent. We demonstrate that, for a 20:1 ratio of base:crosslinker mixture, a striking 150% enhancement of Maxwell strain occurs at 1 Hz actuating frequency.

  11. Simulation of Micro-electromechanical Systems (MEMS) for the Next Generation Space Telescope

    NASA Astrophysics Data System (ADS)

    Kuhn, J. L.; Barclay, R. B.; Dutta, S. B.; Freund, M. M.; Greenhouse, M. A.; Moseley, S. H.

    2000-12-01

    The NASA Goddard Space Flight Center (GSFC) is developing optical micro-electromechanical system (MEMS) components for potential application in Next Generation Space Telescope (NGST) science instruments. In this work, we present an overview of the electro-mechanical simulation of three MEMS components for NGST, which include a reflective micro-mirror array and transmissive microshutter array for aperture control for a near infrared (NIR) multi-object spectrometer and a large aperture MEMS Fabry-Perot tunable filter for a NIR wide field camera. In all cases the device must operate at cryogenic temperatures with low power consumption and low, CMOS compatible, voltages. The goal of our simulation efforts is to adaquately predict both the performance and the reliability of the devices during ground handling, launch, and operation to prevent failures late in the development process and during flight. This goal requires detailed modeling and validation of complex electro-thermal-mechanical interactions and very large non-linear deformations, often involving surface contact. Various parameters such as spatial dimensions and device response are often difficult to measure reliably at these small scales. In addition, these devices are fabricated from a wide variety of materials including surface micro-machined aluminum, reactive ion etched (RIE) silicon nitride, and deep reactive ion etched (DRIE) bulk single crystal silicon. The above broad set of conditions combine to be a formidable challenge for space flight qualification analysis. These simulations represent NASA/GSFC's first attempts at implementing a comprehensive strategy to address complex MEMS structures.

  12. ToF-SIMS Characterization of Biocompatible Silk/Polypyrrole Electromechanical Actuators

    NASA Astrophysics Data System (ADS)

    Bradshaw, Nathan; Severt, Sean; Wang, Zhaoying; Klemke, Carly; Larson, Jesse; Zhu, Zihua; Murphy, Amanda; Leger, Janelle

    2015-03-01

    Materials capable of controlled movements that can also interface with biological environments are highly sought after for biomedical devices such as valves, blood vessel sutures, cochlear implants and controlled drug release devices. Recently we have reported the synthesis of films composed of a conductive interpenetrating network of the biopolymer silk fibroin and poly(pyrrole). These silk-PPy composites function as bilayer electromechanical actuators in a biologically-relevant environment, can be actuated repeatedly, and are able to generate forces comparable with natural muscle (>0.1 MPa), making them an ideal candidate for interfacing with biological tissues. Here, time of flight secondary ion mass spectrometry was used to investigate the migration of ions in the devices during actuation. These findings will be discussed in the context of the actuation mechanism and opportunities for further improvements in device stability and performance.

  13. Controlling Micro ElectroMechanical Systems (MEMS) in Space

    NASA Astrophysics Data System (ADS)

    Farrar, D.; Schneider, W.; Osiander, R.; Champion, J. L.; Darrin, A. G.; Douglas, D.; Swanson, T. D.

    2003-01-01

    Small spacecraft, including micro and nanosats, as they are envisioned for future missions, will require an alternative means to achieve thermal control due to their small power and mass budgets. One of the proposed alternatives is Variable Emittance (Vari-E) Coatings for spacecraft radiators. Space Technology-5 (ST-5) is a technology demonstration mission through NASA Goddard Space Flight Center (GSFC) that will utilize Vari-E Coatings. This mission involves a constellation of three (3) satellites in a highly elliptical orbit with a perigee altitude of ~200 km and an apogee of ~38,000 km. Such an environment will expose the spacecraft to a wide swing in the thermal and radiation environment of the earth's atmosphere. There are three (3) different technologies associated with this mission. The three technologies are electrophoretic, electrochromic, and Micro ElectroMechanical Systems (MEMS). The ultimate goal is to make use of Vari-E coatings, in order to achieve various levels of thermal control. The focus of this paper is to highlight the Vari-E Coating MEMS instrument, with an emphasis on the Electronic Control Unit responsible for operating the MEMS device. The Test & Evaluation approach, along with the results, is specific for application on ST-5, yet the information provides a guideline for future experiments and/or thermal applications on the exterior structure of a spacecraft.

  14. Acoustic energy harvesting using an electromechanical Helmholtz resonator.

    PubMed

    Liu, Fei; Phipps, Alex; Horowitz, Stephen; Ngo, Khai; Cattafesta, Louis; Nishida, Toshikazu; Sheplak, Mark

    2008-04-01

    This paper presents the development of an acoustic energy harvester using an electromechanical Helmholtz resonator (EMHR). The EMHR consists of an orifice, cavity, and a piezoelectric diaphragm. Acoustic energy is converted to mechanical energy when sound incident on the orifice generates an oscillatory pressure in the cavity, which in turns causes the vibration of the diaphragm. The conversion of acoustic energy to electrical energy is achieved via piezoelectric transduction in the diaphragm of the EMHR. Moreover, the diaphragm is coupled with energy reclamation circuitry to increase the efficiency of the energy conversion. Lumped element modeling of the EMHR is used to provide physical insight into the coupled energy domain dynamics governing the energy reclamation process. The feasibility of acoustic energy reclamation using an EMHR is demonstrated in a plane wave tube for two power converter topologies. The first is comprised of only a rectifier, and the second uses a rectifier connected to a flyback converter to improve load matching. Experimental results indicate that approximately 30 mW of output power is harvested for an incident sound pressure level of 160 dB with a flyback converter. Such power level is sufficient to power a variety of low power electronic devices. PMID:18397006

  15. Fundamental design concepts in multi-lane smart electromechanical actuators

    NASA Astrophysics Data System (ADS)

    Annaz, Fawaz Yahya

    2005-12-01

    The most fundamental concept in designing multi-lane smart electromechanical actuation systems, besides meeting performance requirements, is the realization of high integrity. The essential requirements for realizing high integrity (and in any safety-critical system) are hardware redundancy and intelligent monitoring. To correctly detect, identify, isolate and replace redundant components, an intelligent fault detection and fault isolation scheme is required. The effectiveness of any fault detection and fault isolation system is assessed by examining promptness of detection, sensitivity, missed fault detection, the rate of false alarms, and incorrect fault identification. These terms are very much dependent on the threshold values of the monitoring devices imbedded in the system. The main aim of this paper is to provide fundamental consolidation designs and monitoring schemes in different architectures. It will address single-type and two-type summing architectures and highlight feedback sensor integration and monitoring strategies in the former, and explore the suitability of different threshold setting methodologies such as a simulation-graphical based Monte Carlo method, decision theory and analysis of variance. The paper will also address other fundamentals that are essential at the design stage, such as control surface load estimation, force fight (between mismatch lanes) reduction through lane equalization, and threshold setting concepts (scheduled and unscheduled) in a multi-mode operation system. The analysis is based on a four-lane actuation system capable of driving aerodynamic and inertial loads (with two lanes failed) of an aileron control surface similar to that of the Sea Harrier.

  16. Non-contact detection of myocardium's mechanical activity by ultrawideband RF-radar and interpretation applying electrocardiography.

    PubMed

    Thiel, F; Kreiseler, D; Seifert, F

    2009-11-01

    Electromagnetic waves can propagate through the body and are reflected at interfaces between materials with different dielectric properties. Therefore the reason for using ultrawideband (UWB) radar for probing the human body in the frequency range from 100 MHz up to 10 GHz is obvious and suggests an ability to monitor the motion of organs within the human body as well as obtaining images of internal structures. The specific advantages of UWB sensors are high temporal and spatial resolutions, penetration into object, low integral power, and compatibility with established narrowband systems. The sensitivity to ultralow power signals makes them suitable for human medical applications including mobile and continuous noncontact supervision of vital functions. Since no ionizing radiation is used, and due to the ultralow specific absorption rate applied, UWB techniques permit noninvasive sensing with no potential risks. This research aims at the synergetic use of UWB sounding combined with magnetic resonance imaging (MRI) to gain complementary information for improved functional diagnosis and imaging, especially to accelerate and enhance cardiac MRI by applying UWB radar as a noncontact navigator of myocardial contraction. To this end a sound understanding of how myocardial's mechanic is rendered by reflected and postprocessed UWB radar signals must be achieved. Therefore, we have executed the simultaneous acquisition and evaluation of radar signals with signals from a high-resolution electrocardiogram. The noncontact UWB illumination was done from several radiographic standard positions to monitor selected superficial myocardial areas during the cyclic physiological myocardial deformation in three different respiratory states. From our findings we could conclude that UWB radar can serve as a navigator technique for high and ultrahigh field magnetic resonance imaging and can be beneficial preserving the high resolution capability of this imaging modality. Furthermore it

  17. Non-contact detection of myocardium's mechanical activity by ultrawideband RF-radar and interpretation applying electrocardiography

    NASA Astrophysics Data System (ADS)

    Thiel, F.; Kreiseler, D.; Seifert, F.

    2009-11-01

    Electromagnetic waves can propagate through the body and are reflected at interfaces between materials with different dielectric properties. Therefore the reason for using ultrawideband (UWB) radar for probing the human body in the frequency range from 100 MHz up to 10 GHz is obvious and suggests an ability to monitor the motion of organs within the human body as well as obtaining images of internal structures. The specific advantages of UWB sensors are high temporal and spatial resolutions, penetration into object, low integral power, and compatibility with established narrowband systems. The sensitivity to ultralow power signals makes them suitable for human medical applications including mobile and continuous noncontact supervision of vital functions. Since no ionizing radiation is used, and due to the ultralow specific absorption rate applied, UWB techniques permit noninvasive sensing with no potential risks. This research aims at the synergetic use of UWB sounding combined with magnetic resonance imaging (MRI) to gain complementary information for improved functional diagnosis and imaging, especially to accelerate and enhance cardiac MRI by applying UWB radar as a noncontact navigator of myocardial contraction. To this end a sound understanding of how myocardial's mechanic is rendered by reflected and postprocessed UWB radar signals must be achieved. Therefore, we have executed the simultaneous acquisition and evaluation of radar signals with signals from a high-resolution electrocardiogram. The noncontact UWB illumination was done from several radiographic standard positions to monitor selected superficial myocardial areas during the cyclic physiological myocardial deformation in three different respiratory states. From our findings we could conclude that UWB radar can serve as a navigator technique for high and ultrahigh field magnetic resonance imaging and can be beneficial preserving the high resolution capability of this imaging modality. Furthermore it

  18. Multimodal electromechanical model of piezoelectric transformers by Hamilton's principle.

    PubMed

    Nadal, Clement; Pigache, Francois

    2009-11-01

    This work deals with a general energetic approach to establish an accurate electromechanical model of a piezoelectric transformer (PT). Hamilton's principle is used to obtain the equations of motion for free vibrations. The modal characteristics (mass, stiffness, primary and secondary electromechanical conversion factors) are also deduced. Then, to illustrate this general electromechanical method, the variational principle is applied to both homogeneous and nonhomogeneous Rosen-type PT models. A comparison of modal parameters, mechanical displacements, and electrical potentials are presented for both models. Finally, the validity of the electrodynamical model of nonhomogeneous Rosen-type PT is confirmed by a numerical comparison based on a finite elements method and an experimental identification.

  19. Non-Contact Plant Growth Measurement Method and System Based on Ubiquitous Sensor Network Technologies

    PubMed Central

    Suk, Jinweon; Kim, Seokhoon; Ryoo, Intae

    2011-01-01

    This paper proposes a non-contact plant growth measurement system using infrared sensors based on the ubiquitous sensor network (USN) technology. The proposed system measures plant growth parameters such as the stem radius of plants using real-time non-contact methods, and generates diameter, cross-sectional area and thickening form of plant stems using this measured data. Non-contact sensors have been used not to cause any damage to plants during measurement of the growth parameters. Once the growth parameters are measured, they are transmitted to a remote server using the sensor network technology and analyzed in the application program server. The analyzed data are then provided for administrators and a group of interested users. The proposed plant growth measurement system has been designed and implemented using fixed-type and rotary-type infrared sensor based measurement methods and devices. Finally, the system performance is compared and verified with the measurement data that have been obtained by practical field experiments. PMID:22163849

  20. Demonstration of a non-contact x-ray source using an inductively heated pyroelectric accelerator

    NASA Astrophysics Data System (ADS)

    Klopfer, Michael; Satchouk, Vladimir; Cao, Anh; Wolowiec, Thomas; Alivov, Yahya; Molloi, Sabee

    2015-04-01

    X-ray emission from pyroelectric sources can be produced through non-contact thermal cycling using induction heating. In this study, we demonstrated a proof of concept non-contact x-ray source powered via induction heating. An induction heater operating at 62.5 kHz provided a total of 6.5 W of delivered peak thermal power with 140 V DC of driving voltage. The heat was applied to a ferrous substrate mechanically coupled to a cubic 1 cm3 Lithium Niobate (LiNbO3) pyroelectric crystal maintained in a 3-12 mTorr vacuum. The maximum temperature reached was 175 °C in 86 s of heating. The cooling cycle began immediately after heating and was provided by passive radiative cooling. The total combined cycle time was 250 s. x-ray photons were produced and analyzed in both heating and cooling phases. Maximum photon energies of 59 keV and 55 keV were observed during heating and cooling, respectively. Non-contact devices such as this, may find applications in cancer therapy (brachytherapy), non-destructive testing, medical imaging, and physics education fields.

  1. Design and fabrication of a flexible MEMS-based electromechanical sensor array for breast cancer diagnosis

    PubMed Central

    Pandya, Hardik J.; Park, Kihan; Desai, Jaydev P.

    2015-01-01

    The use of flexible micro-electro-mechanical systems (MEMS) based device provides a unique opportunity in bio-medical robotics such as characterization of normal and malignant tissues. This paper reports on design and development of a flexible MEMS-based sensor array integrating mechanical and electrical sensors on the same platform to enable the study of the change in electro-mechanical properties of the benign and cancerous breast tissues. In this work, we present the analysis for the electrical characterization of the tissue specimens and also demonstrate the feasibility of using the sensor for mechanical characterization of the tissue specimens. Eight strain gauges acting as mechanical sensors were fabricated using poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) conducting polymer on poly(dimethylsiloxane) (PDMS) as the substrate material. Eight electrical sensors were fabricated using SU-8 pillars on gold (Au) pads which were patterned on the strain gauges separated by a thin insulator (SiO2 1.0μm). These pillars were coated with gold to make it conducting. The electromechanical sensors are integrated on the same substrate. The sensor array covers 180μm × 180μm area and the size of the complete device is 20mm in diameter. The diameter of each breast tissue core used in the present study was 1mm and the thickness was 8μm. The region of interest was 200μm × 200μm. Microindentation technique was used to characterize the mechanical properties of the breast tissues. The sensor is integrated with conducting SU-8 pillars to study the electrical property of the tissue. Through electro-mechanical characterization studies using this MEMS-based sensor, we were able to measure the accuracy of the fabricated device and ascertain the difference between benign and cancer breast tissue specimens. PMID:26526747

  2. High-Throughput Non-Contact Vitrification of Cell-Laden Droplets Based on Cell Printing

    NASA Astrophysics Data System (ADS)

    Shi, Meng; Ling, Kai; Yong, Kar Wey; Li, Yuhui; Feng, Shangsheng; Zhang, Xiaohui; Pingguan-Murphy, Belinda; Lu, Tian Jian; Xu, Feng

    2015-12-01

    Cryopreservation is the most promising way for long-term storage of biological samples e.g., single cells and cellular structures. Among various cryopreservation methods, vitrification is advantageous by employing high cooling rate to avoid the formation of harmful ice crystals in cells. Most existing vitrification methods adopt direct contact of cells with liquid nitrogen to obtain high cooling rates, which however causes the potential contamination and difficult cell collection. To address these limitations, we developed a non-contact vitrification device based on an ultra-thin freezing film to achieve high cooling/warming rate and avoid direct contact between cells and liquid nitrogen. A high-throughput cell printer was employed to rapidly generate uniform cell-laden microdroplets into the device, where the microdroplets were hung on one side of the film and then vitrified by pouring the liquid nitrogen onto the other side via boiling heat transfer. Through theoretical and experimental studies on vitrification processes, we demonstrated that our device offers a high cooling/warming rate for vitrification of the NIH 3T3 cells and human adipose-derived stem cells (hASCs) with maintained cell viability and differentiation potential. This non-contact vitrification device provides a novel and effective way to cryopreserve cells at high throughput and avoid the contamination and collection problems.

  3. High-Throughput Non-Contact Vitrification of Cell-Laden Droplets Based on Cell Printing.

    PubMed

    Shi, Meng; Ling, Kai; Yong, Kar Wey; Li, Yuhui; Feng, Shangsheng; Zhang, Xiaohui; Pingguan-Murphy, Belinda; Lu, Tian Jian; Xu, Feng

    2015-01-01

    Cryopreservation is the most promising way for long-term storage of biological samples e.g., single cells and cellular structures. Among various cryopreservation methods, vitrification is advantageous by employing high cooling rate to avoid the formation of harmful ice crystals in cells. Most existing vitrification methods adopt direct contact of cells with liquid nitrogen to obtain high cooling rates, which however causes the potential contamination and difficult cell collection. To address these limitations, we developed a non-contact vitrification device based on an ultra-thin freezing film to achieve high cooling/warming rate and avoid direct contact between cells and liquid nitrogen. A high-throughput cell printer was employed to rapidly generate uniform cell-laden microdroplets into the device, where the microdroplets were hung on one side of the film and then vitrified by pouring the liquid nitrogen onto the other side via boiling heat transfer. Through theoretical and experimental studies on vitrification processes, we demonstrated that our device offers a high cooling/warming rate for vitrification of the NIH 3T3 cells and human adipose-derived stem cells (hASCs) with maintained cell viability and differentiation potential. This non-contact vitrification device provides a novel and effective way to cryopreserve cells at high throughput and avoid the contamination and collection problems. PMID:26655688

  4. High-Throughput Non-Contact Vitrification of Cell-Laden Droplets Based on Cell Printing

    PubMed Central

    Shi, Meng; Ling, Kai; Yong, Kar Wey; Li, Yuhui; Feng, Shangsheng; Zhang, Xiaohui; Pingguan-Murphy, Belinda; Lu, Tian Jian; Xu, Feng

    2015-01-01

    Cryopreservation is the most promising way for long-term storage of biological samples e.g., single cells and cellular structures. Among various cryopreservation methods, vitrification is advantageous by employing high cooling rate to avoid the formation of harmful ice crystals in cells. Most existing vitrification methods adopt direct contact of cells with liquid nitrogen to obtain high cooling rates, which however causes the potential contamination and difficult cell collection. To address these limitations, we developed a non-contact vitrification device based on an ultra-thin freezing film to achieve high cooling/warming rate and avoid direct contact between cells and liquid nitrogen. A high-throughput cell printer was employed to rapidly generate uniform cell-laden microdroplets into the device, where the microdroplets were hung on one side of the film and then vitrified by pouring the liquid nitrogen onto the other side via boiling heat transfer. Through theoretical and experimental studies on vitrification processes, we demonstrated that our device offers a high cooling/warming rate for vitrification of the NIH 3T3 cells and human adipose-derived stem cells (hASCs) with maintained cell viability and differentiation potential. This non-contact vitrification device provides a novel and effective way to cryopreserve cells at high throughput and avoid the contamination and collection problems. PMID:26655688

  5. Coupled Biomechanical Response of the Cornea Assessed by Non-Contact Tonometry. A Simulation Study

    PubMed Central

    2015-01-01

    The mechanical response of the cornea subjected to a non-contact air-jet tonometry diagnostic test represents an interplay between its geometry, the corneal material behavior and the loading. The objective is to study this interplay to better understand and interpret the results obtained with a non-contact tonometry test. A patient-specific finite element model of a healthy eye, accounting for the load free configuration, was used. The corneal tissue was modeled as an anisotropic hyperelastic material with two preferential directions. Three different sets of parameters within the human experimental range obtained from inflation tests were considered. The influence of the IOP was studied by considering four pressure levels (10–28 mmHg) whereas the influence of corneal thickness was studied by inducing a uniform variation (300–600 microns). A Computer Fluid Dynamics (CFD) air-jet simulation determined pressure loading exerted on the anterior corneal surface. The maximum apex displacement showed a linear variation with IOP for all materials examined. On the contrary, the maximum apex displacement followed a cubic relation with corneal thickness. In addition, a significant sensitivity of the apical displacement to the corneal stiffness was also obtained. Explanation to this behavior was found in the fact that the cornea experiences bending when subjected to an air-puff loading, causing the anterior surface to work in compression whereas the posterior surface works in tension. Hence, collagen fibers located at the anterior surface do not contribute to load bearing. Non-contact tonometry devices give useful information that could be misleading since the corneal deformation is the result of the interaction between the mechanical properties, IOP, and geometry. Therefore, a non-contact tonometry test is not sufficient to evaluate their individual contribution and a complete in-vivo characterization would require more than one test to independently determine the membrane

  6. 13. INTERIOR, OPERATOR'S HOUSE, ELECTROMECHANICAL INTERLOCKING MACHINE New York, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. INTERIOR, OPERATOR'S HOUSE, ELECTRO-MECHANICAL INTERLOCKING MACHINE - New York, New Haven & Hartford Railroad, Mystic River Bridge, Spanning Mystic River between Groton & Stonington, Groton, New London County, CT

  7. Non-contact scanning measurement utilizing a space mapping method

    NASA Astrophysics Data System (ADS)

    Chang, Ming; Lin, Kao-Hui

    1998-12-01

    In this study, a novel approach to a measuring methodology and calibration method for an optical non-contact scanning probe system is proposed and verified by experiments. The optical probe consists of a line laser diode and two charge-coupled device (CCD) cameras and is placed on a computer numerical control (CNC) machine to measure the workpiece profiles. A space mapping method using the least-squares algorithm is presented for the probe calibration and profile measurement. This method provides a simple and accurate calculation of the relationship between the real space plane and its related image space plane in a CCD camera. A transparent grid with regularly spaced nodal points is used to construct the space mapping function. The space coordinate of an object can be obtained from its image in the CCD camera via the mapping function. The measured profile data are smoothed by the B-spline blending function and can be transferred to a CAD/CAM package for industrial applications. Experimental results show that this technique can determine the 3-D profile of an object with an accuracy of 60 μm.

  8. An imaging colorimeter for noncontact tissue color mapping.

    PubMed

    Balas, C

    1997-06-01

    There has been a considerable effort in several medical fields, for objective color analysis and characterization of biological tissues. Conventional colorimeters have proved inadequate for this purpose, since they do not provide spatial color information and because the measuring procedure randomly affects the color of the tissue. In this paper an imaging colorimeter is presented, where the nonimaging optical photodetector of colorimeters is replaced with the charge-coupled device (CCD) sensor of a color video camera, enabling the independent capturing of the color information for any spatial point within its field-of-view. Combining imaging and colorimetry methods, the acquired image is calibrated and corrected, under several ambient light conditions, providing noncontact reproducible color measurements and mapping, free of the errors and the limitations present in conventional colorimeters. This system was used for monitoring of blood supply changes of psoriatic plaques, that have undergone Psoralens and ultraviolet-A radiation (PUVA) therapy, where reproducible and reliable measurements were demonstrated. These features highlight the potential of the imaging colorimeters as clinical and research tools for the standardization of clinical diagnosis and for the objective evaluation of treatment effectiveness. PMID:9151480

  9. Electro-mechanical energy conversion system having a permanent magnet machine with stator, resonant transfer link and energy converter controls

    DOEpatents

    Skeist, S. Merrill; Baker, Richard H.

    2006-01-10

    An electro-mechanical energy conversion system coupled between an energy source and an energy load comprising an energy converter device including a permanent magnet induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer to control the flow of power or energy through the permanent magnetic induction machine.

  10. Atrial Electromechanical Coupling in Patients with Lichen Planus

    PubMed Central

    Yaman, Mehmet; Beton, Osman; Asarcıklı, Lale Dinç; Aksakal, Aytekin; Dogdu, Orhan

    2016-01-01

    Background and objectives A chronic inflammatory disease, lichen planus may cause disturbance of atrial electromechanical coupling and increase the risk of atrial fibrillation. The aim of this study was to evaluate atrial electromechanical delay with both electrocardiography (ECG) and echocardiography in patients with lichen planus (LP). Subjects and Methods Seventy-two LP patients (43 males [59.7%], mean age: 44.0±16.7 years) were enrolled in this cross-sectional case-control study. The control group was selected in a 1:1 ratio from 70 patients in an age and sex matched manner. P wave dispersion was measured by ECG to show atrial electromechanical delay. All of the patients underwent transthoracic echocardiography for measuring inter- and intra-atrial electromechanical delays. Results The baseline characteristics of the patients and the control group were similar except for the presence of LP. P-wave dispersion measured by ECG was significantly higher in patients with LP (p<0.001). Patients with LP had significantly prolonged intra- and interatrial electromechanical delays when compared to the control group (p<0.001). In addition, all of these variables were significantly correlated with high sensitive C-reactive protein (hsCRP) levels. Conclusion Atrial electromechanical coupling, which is significantly correlated with increased hsCRP levels, is impaired in patients with LP. PMID:27482262

  11. Non- contacting capacitive diagnostic device

    DOEpatents

    Ellison, Timothy

    2005-07-12

    A non-contacting capacitive diagnostic device includes a pulsed light source for producing an electric field in a semiconductor or photovoltaic device or material to be evaluated and a circuit responsive to the electric field. The circuit is not in physical contact with the device or material being evaluated and produces an electrical signal characteristic of the electric field produced in the device or material. The diagnostic device permits quality control and evaluation of semiconductor or photovoltaic device properties in continuous manufacturing processes.

  12. Flywheel energy storage for electromechanical actuation systems

    NASA Technical Reports Server (NTRS)

    Hockney, Richard L.; Goldie, James H.; Kirtley, James L.

    1991-01-01

    The authors describe a flywheel energy storage system designed specifically to provide load-leveling for a thrust vector control (TVC) system using electromechanical actuators (EMAs). One of the major advantages of an EMA system over a hydraulic system is the significant reduction in total energy consumed during the launch profile. Realization of this energy reduction will, however, require localized energy storage capable of delivering the peak power required by the EMAs. A combined flywheel-motor/generator unit which interfaces directly to the 20-kHz power bus represents an ideal candidate for this load leveling. The overall objective is the definition of a flywheel energy storage system for this application. The authors discuss progress on four technical objectives: (1) definition of the specifications for the flywheel-motor/generator system, including system-level trade-off analysis; (2) design of the flywheel rotor; (3) design of the motor/generator; and (4) determination of the configuration for the power management system.

  13. 40 HP Electro-Mechanical Actuator

    NASA Technical Reports Server (NTRS)

    Fulmer, Chris

    1996-01-01

    This report summarizes the work performed on the 40 BP electro-mechanical actuator (EMA) system developed on NASA contract NAS3-25799 for the NASA National Launch System and Electrical Actuation (ELA) Technology Bridging Programs. The system was designed to demonstrate the capability of large, high power linear ELA's for applications such as Thrust Vector Control (TVC) on rocket engines. It consists of a motor controller, high frequency power source, drive electronics and a linear actuator. The power source is a 25kVA 20 kHz Mapham inverter. The drive electronics are based on the pulse population modulation concept and operate at a nominal frequency of 40 kHz. The induction motor is a specially designed high speed, low inertia motor capable of a 68 peak HP. The actuator was originally designed by MOOG Aerospace under an internal R & D program to meet Space Shuttle Main Engine (SSME) TVC requirements. The design was modified to meet this programs linear rate specification of 7.4 inches/second. The motor and driver were tested on a dynamometer at the Martin Marietta Space Systems facility. System frequency response and step response tests were conducted at the Marshall Space Flight Center facility. A complete description of the system and all test results can be found in the body of the report.

  14. Solitary electromechanical pulses in lobster neurons.

    PubMed

    Gonzalez-Perez, A; Mosgaard, L D; Budvytyte, R; Villagran-Vargas, E; Jackson, A D; Heimburg, T

    2016-09-01

    Investigations of nerve activity have focused predominantly on electrical phenomena. Nerves, however, are thermodynamic systems, and changes in temperature and in the dimensions of the nerve can also be observed during the action potential. Measurements of heat changes during the action potential suggest that the nerve pulse shares many characteristics with an adiabatic pulse. First experiments in the 1980s suggested small changes in nerve thickness and length during the action potential. Such findings have led to the suggestion that the action potential may be related to electromechanical solitons traveling without dissipation. However, there have been no modern attempts to study mechanical phenomena in nerves. Here, we present ultrasensitive AFM recordings of mechanical changes on the order of 2-12Å in the giant axons of the lobster. We show that the nerve thickness changes in phase with voltage changes. When stimulated at opposite ends of the same axon, colliding action potentials pass through one another and do not annihilate. These observations are consistent with a mechanical interpretation of the nervous impulse. PMID:27448851

  15. Solitary electromechanical pulses in lobster neurons.

    PubMed

    Gonzalez-Perez, A; Mosgaard, L D; Budvytyte, R; Villagran-Vargas, E; Jackson, A D; Heimburg, T

    2016-09-01

    Investigations of nerve activity have focused predominantly on electrical phenomena. Nerves, however, are thermodynamic systems, and changes in temperature and in the dimensions of the nerve can also be observed during the action potential. Measurements of heat changes during the action potential suggest that the nerve pulse shares many characteristics with an adiabatic pulse. First experiments in the 1980s suggested small changes in nerve thickness and length during the action potential. Such findings have led to the suggestion that the action potential may be related to electromechanical solitons traveling without dissipation. However, there have been no modern attempts to study mechanical phenomena in nerves. Here, we present ultrasensitive AFM recordings of mechanical changes on the order of 2-12Å in the giant axons of the lobster. We show that the nerve thickness changes in phase with voltage changes. When stimulated at opposite ends of the same axon, colliding action potentials pass through one another and do not annihilate. These observations are consistent with a mechanical interpretation of the nervous impulse.

  16. Designing Piezoelectric Films for Micro Electromechanical Systems

    SciTech Connect

    Trolier-McKinstry, Susan; Griggio, Flavio; Yaeger, Charles; Jousse, Pierre; Zhao, Dalong; Bharadwaja, Srowthi; Jackson, Thomas N; Jesse, Stephen; Kalinin, Sergei V; Wasa, Kiyotaka

    2011-01-01

    Piezoelectric thin films are of increasing interest in low-voltage micro electromechanical systems for sensing, actuation, and energy harvesting. They also serve as model systems to study fundamental behavior in piezoelectrics. Next-generation technologies such as ultrasound pill cameras, flexible ultrasound arrays, and energy harvesting systems for unattended wireless sensors will all benefit from improvements in the piezoelectric properties of the films. This paper describes tailoring the composition, microstructure, orientation of thin films, and substrate choice to optimize the response. It is shown that increases in the grain size of lead-based perovskite films from 75 to 300 nm results in 40 and 20% increases in the permittivity and piezoelectric coefficients, respectively. This is accompanied by an increase in the nonlinearity in the response. Band excitation piezoresponse force microscopy was used to interrogate the nonlinearity locally. It was found that chemical solution-derived PbZr(0.52)Ti(0.48)O(3) thin films show clusters of larger nonlinear response embedded in a more weakly nonlinear matrix. The scale of the clusters significantly exceeds that of the grain size, suggesting that collective motion of many domain walls contributes to the observed Rayleigh behavior in these films. Finally, it is shown that it is possible to increase the energy-harvesting figure of merit through appropriate materials choice, strong imprint, and composite connectivity patterns.

  17. Toward GPGPU accelerated human electromechanical cardiac simulations

    PubMed Central

    Vigueras, Guillermo; Roy, Ishani; Cookson, Andrew; Lee, Jack; Smith, Nicolas; Nordsletten, David

    2014-01-01

    In this paper, we look at the acceleration of weakly coupled electromechanics using the graphics processing unit (GPU). Specifically, we port to the GPU a number of components of Heart—a CPU-based finite element code developed for simulating multi-physics problems. On the basis of a criterion of computational cost, we implemented on the GPU the ODE and PDE solution steps for the electrophysiology problem and the Jacobian and residual evaluation for the mechanics problem. Performance of the GPU implementation is then compared with single core CPU (SC) execution as well as multi-core CPU (MC) computations with equivalent theoretical performance. Results show that for a human scale left ventricle mesh, GPU acceleration of the electrophysiology problem provided speedups of 164 × compared with SC and 5.5 times compared with MC for the solution of the ODE model. Speedup of up to 72 × compared with SC and 2.6 × compared with MC was also observed for the PDE solve. Using the same human geometry, the GPU implementation of mechanics residual/Jacobian computation provided speedups of up to 44 × compared with SC and 2.0 × compared with MC. © 2013 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons, Ltd. PMID:24115492

  18. COMPACT NON-CONTACT TOTAL EMISSION DETECTION FOR IN-VIVO MULTI-PHOTON EXCITATION MICROSCOPY

    PubMed Central

    Glancy, Brian; Karamzadeh, Nader S.; Gandjbakhche, Amir H.; Redford, Glen; Kilborn, Karl; Knutson, Jay R.; Balaban, Robert S.

    2014-01-01

    Summary We describe a compact, non-contact design for a Total Emission Detection (c-TED) system for intra-vital multi-photon imaging. To conform to a standard upright two-photon microscope design, this system uses a parabolic mirror surrounding a standard microscope objective in concert with an optical path that does not interfere with normal microscope operation. The non-contact design of this device allows for maximal light collection without disrupting the physiology of the specimen being examined. Tests were conducted on exposed tissues in live animals to examine the emission collection enhancement of the c-TED device compared to heavily optimized objective-based emission collection. The best light collection enhancement was seen from murine fat (5×-2× gains as a function of depth), while murine skeletal muscle and rat kidney showed gains of over two and just under two-fold near the surface, respectively. Gains decreased with imaging depth (particularly in the kidney). Zebrafish imaging on a reflective substrate showed close to a two-fold gain throughout the entire volume of an intact embryo (approximately 150 μm deep). Direct measurement of bleaching rates confirmed that the lower laser powers (enabled by greater light collection efficiency) yielded reduced photobleaching in vivo. The potential benefits of increased light collection in terms of speed of imaging and reduced photo-damage, as well as the applicability of this device to other multi-photon imaging methods is discussed. PMID:24251437

  19. Noncontact friction via capillary shear interaction at nanoscale.

    PubMed

    Lee, Manhee; Kim, Bongsu; Kim, Jongwoo; Jhe, Wonho

    2015-01-01

    Friction in an ambient condition involves highly nonlinear interactions of capillary force, induced by the capillary-condensed water nanobridges between contact or noncontact asperities of two sliding surfaces. Since the real contact area of sliding solids is much smaller than the apparent contact area, the nanobridges formed on the distant asperities can contribute significantly to the overall friction. Therefore, it is essential to understand how the water nanobridges mediate the 'noncontact' friction, which helps narrow the gap between our knowledge of friction on the microscopic and macroscopic scales. Here we show, by using noncontact dynamic force spectroscopy, the single capillary bridge generates noncontact friction via its shear interaction. The pinning-depinning dynamics of the nanobridge's contact line produces nonviscous damping, which occurs even without normal load and dominates the capillary-induced hydrodynamic damping. The novel nanofriction mechanism may provide a deeper microscopic view of macroscopic friction in air where numerous asperities exist. PMID:26066909

  20. Noncontact friction via capillary shear interaction at nanoscale

    PubMed Central

    Lee, Manhee; Kim, Bongsu; Kim, Jongwoo; Jhe, Wonho

    2015-01-01

    Friction in an ambient condition involves highly nonlinear interactions of capillary force, induced by the capillary-condensed water nanobridges between contact or noncontact asperities of two sliding surfaces. Since the real contact area of sliding solids is much smaller than the apparent contact area, the nanobridges formed on the distant asperities can contribute significantly to the overall friction. Therefore, it is essential to understand how the water nanobridges mediate the ‘noncontact' friction, which helps narrow the gap between our knowledge of friction on the microscopic and macroscopic scales. Here we show, by using noncontact dynamic force spectroscopy, the single capillary bridge generates noncontact friction via its shear interaction. The pinning–depinning dynamics of the nanobridge's contact line produces nonviscous damping, which occurs even without normal load and dominates the capillary-induced hydrodynamic damping. The novel nanofriction mechanism may provide a deeper microscopic view of macroscopic friction in air where numerous asperities exist. PMID:26066909

  1. Noncontact friction via capillary shear interaction at nanoscale

    NASA Astrophysics Data System (ADS)

    Lee, Manhee; Kim, Bongsu; Kim, Jongwoo; Jhe, Wonho

    2015-06-01

    Friction in an ambient condition involves highly nonlinear interactions of capillary force, induced by the capillary-condensed water nanobridges between contact or noncontact asperities of two sliding surfaces. Since the real contact area of sliding solids is much smaller than the apparent contact area, the nanobridges formed on the distant asperities can contribute significantly to the overall friction. Therefore, it is essential to understand how the water nanobridges mediate the `noncontact' friction, which helps narrow the gap between our knowledge of friction on the microscopic and macroscopic scales. Here we show, by using noncontact dynamic force spectroscopy, the single capillary bridge generates noncontact friction via its shear interaction. The pinning-depinning dynamics of the nanobridge's contact line produces nonviscous damping, which occurs even without normal load and dominates the capillary-induced hydrodynamic damping. The novel nanofriction mechanism may provide a deeper microscopic view of macroscopic friction in air where numerous asperities exist.

  2. Non-Contact Electrical Conductivity Measurement Technique for Molten Metals

    NASA Technical Reports Server (NTRS)

    Rhim, W. K.; Ishikawa, T.

    1998-01-01

    A non-contact technique of measuring the electrical conductivity (or resistivity) of conducting liquids while they are levitated by the high temperature electrostatic levitator in a high vacuum is reported.

  3. Thermal Remote Anemometer Device

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S.; Heath, D. Michele; Winfree, William P.; Miller, William E.; Welch, Christopher S.

    1988-01-01

    Thermal Remote Anemometer Device developed for remote, noncontacting, passive measurement of thermal properties of sample. Model heated locally by scanning laser beam and cooled by wind in tunnel. Thermal image of model analyzed to deduce pattern of airflow around model. For materials applications, system used for evaluation of thin films and determination of thermal diffusivity and adhesive-layer contact. For medical applications, measures perfusion through skin to characterize blood flow and used to determine viabilities of grafts and to characterize tissues.

  4. Electronic Non-Contacting Linear Position Measuring System

    DOEpatents

    Post, Richard F.

    2005-06-14

    A non-contacting linear position location system employs a special transmission line to encode and transmit magnetic signals to a receiver on the object whose position is to be measured. The invention is useful as a non-contact linear locator of moving objects, e.g., to determine the location of a magnetic-levitation train for the operation of the linear-synchronous motor drive system.

  5. Non-contact transportation using near-field acoustic levitation

    PubMed

    Ueha; Hashimoto; Koike

    2000-03-01

    Near-field acoustic levitation, where planar objects 10 kg in weight can levitate stably near the vibrating plate, is successfully applied both to non-contact transportation of objects and to a non-contact ultrasonic motor. Transporting apparatuses and an ultrasonic motor have been fabricated and their characteristics measured. The theory of near-field acoustic levitation both for a piston-like sound source and a flexural vibration source is also briefly described. PMID:10829622

  6. Control of microwave signals using bichromatic electromechanically induced transparency in multimode circuit electromechanical systems

    NASA Astrophysics Data System (ADS)

    Cheng, Jiang; Yuanshun, Cui; Xintian, Bian; Xiaowei, Li; Guibin, Chen

    2016-05-01

    We theoretically investigate the tunable delay and advancement of microwave signals based on bichromatic electromechanically induced transparency in a three-mode circuit electromechanical system, where two nanomechanical resonators with closely spaced frequencies are independently coupled to a common microwave cavity. In the presence of a strong microwave pump field, we obtain two transparency windows accompanied by steep phase dispersion in the transmitted microwave probe field. The width of the transparency window and the group delay of the probe field can be controlled effectively by the power of the pump field. It is shown that the maximum group delay of 0.12 ms and the advancement of 0.27 ms can be obtained in the current experiments. Project supported by the National Natural Science Foundation of China (Grant Nos. 11304110 and 11174101), the Jiangsu Natural Science Foundation, China (Grant Nos. BK20130413 and BK2011411), and the Natural Science Foundation of Jiangsu Higher Education Institutions of China (Grant Nos. 13KJB140002 and 15KJB460004).

  7. Simultaneous MEMS-based electro-mechanical phenotyping of breast cancer

    PubMed Central

    Pandya, Hardik J.; Park, Kihan; Chen, Wenjin; Chekmareva, Marina A.; Foran, David J.; Desai, Jaydev P.

    2015-01-01

    Carcinomas are the most commonly diagnosed cancers originating in the skin, lungs, breasts, pancreas, and other organs and glands. In most of the cases, the microenvironment within the tissue changes with the progression of disease. A key challenge is to develop a device capable of providing quantitative indicators in diagnosing cancer by measuring alteration in electrical and mechanical property of the tissues from the onset of malignancy. We demonstrate micro-electro-mechanical-systems (MEMS) based flexible polymer microsensor array capable of simultaneously measuring electro-mechanical properties of the breast tissues cores (1mm in diameter and 10μm in thickness) from onset through progression of the cancer. The electrical and mechanical signatures obtained from the tissue cores shows the capability of the device to clearly demarcate the specific stages of cancer in epithelial and stromal regions providing quantitative indicators facilitating the diagnosis of breast cancer. The present study shows that electro-mechanical properties of the breast tissue core at the micro-level are different than those at the macro-level. PMID:26224116

  8. Cardiac Electromechanical Models: From Cell to Organ

    PubMed Central

    Trayanova, Natalia A.; Rice, John Jeremy

    2011-01-01

    The heart is a multiphysics and multiscale system that has driven the development of the most sophisticated mathematical models at the frontiers of computational physiology and medicine. This review focuses on electromechanical (EM) models of the heart from the molecular level of myofilaments to anatomical models of the organ. Because of the coupling in terms of function and emergent behaviors at each level of biological hierarchy, separation of behaviors at a given scale is difficult. Here, a separation is drawn at the cell level so that the first half addresses subcellular/single-cell models and the second half addresses organ models. At the subcellular level, myofilament models represent actin–myosin interaction and Ca-based activation. The discussion of specific models emphasizes the roles of cooperative mechanisms and sarcomere length dependence of contraction force, considered to be the cellular basis of the Frank–Starling law. A model of electrophysiology and Ca handling can be coupled to a myofilament model to produce an EM cell model, and representative examples are summarized to provide an overview of the progression of the field. The second half of the review covers organ-level models that require solution of the electrical component as a reaction–diffusion system and the mechanical component, in which active tension generated by the myocytes produces deformation of the organ as described by the equations of continuum mechanics. As outlined in the review, different organ-level models have chosen to use different ionic and myofilament models depending on the specific application; this choice has been largely dictated by compromises between model complexity and computational tractability. The review also addresses application areas of EM models such as cardiac resynchronization therapy and the role of mechano-electric coupling in arrhythmias and defibrillation. PMID:21886622

  9. Cryogenic Magnetostrictive Materials and Devices

    NASA Astrophysics Data System (ADS)

    Joshi, C. H.; Mavanur, A.; Tai, C.-Y.; Han, Z.-X.; Rodenbush, A. J.; Wong, Y.

    2004-06-01

    Energen has patented KelvinAll™, the first material, to exhibit magnetostrictive properties from elevated temperatures to near absolute zero, opening up a new range of applications for magnetostrictive devices. Magnetostrictive materials change their shape in the presence of a magnetic field. This elongation is precise, predictable, reversible and repeatable thereby enabling practical electromechanical devices. KelvinAll has magnetostriction comparable to Terfenol-D at room temperature and its magnetostriction increases at cryogenic temperatures. Energen has developed and prototyped practical electromechanical devices using KelvinAll. These devices include tuners for superconducting radio frequency (SRF) cavities, components for magnetic refrigerators, flow control valves and precision translation stages some of which will be discussed in greater detail. Energen's KelvinAll products enhance performance, increase reliability and reduce development costs.

  10. Electro-mechanical analogies for modeling the structural impedance response

    NASA Astrophysics Data System (ADS)

    Zagrai, Andrei

    2007-04-01

    Electro-mechanical (E/M) impedance is a powerful structural identification and health monitoring (SHM) technique that allows for inferring high-frequency structural dynamic characteristics directly by interrogating a network of embedded piezoelectric active sensors. In recent years, there has been a considerable interest in expanding range of applications of the electromechanical impedance technique, its synergistic integration into complementary SHM methodologies, and miniaturizing the associated impedance measurement circuitry. The present work is aimed at developing an E/M impedance modeling approach that explores analogies between electrical and mechanical systems and permits representation of the mechanical system elements in terms of equivalent electrical circuits. The advantage of such a representation is that analytical modeling is substantially simplified by considering a network of electrical elements, mechanical quantities are incorporated directly into the electrical model of a measurement unit, and modern circuit design, simulation and analysis software tools can be employed to improve the method performance. The electro-mechanical model of a piezoelectric impedance sensor is discussed and development of the electrical circuit representation of the sensor-structure interaction is presented. The proposed electrical and existing mechanical models are compared showing a good agreement. Applicability of the developed modeling approach is discussed and examples of numerical calculations are provided. It is suggested that describing a sensor-structure electro-mechanical system in terms of electro-mechanical analogies could simplify analytical modeling and improve instrumentation design.

  11. Noncontact vibration measurements using magnetoresistive sensing elements

    NASA Astrophysics Data System (ADS)

    Tomassini, R.; Rossi, G.

    2016-06-01

    Contactless instrumentations is more and more used in turbomachinery testing thanks to the non-intrusive character and the possibility to monitor all the components of the machine at the same time. Performances of blade tip timing (BTT) measurement systems, used for noncontact turbine blade vibration measurements, in terms of uncertainty and resolution are strongly affected by sensor characteristics and processing methods. The sensors used for BTT generate pulses, used for precise measurements of turbine blades time of arrival. Nowadays proximity sensors used in this application are based on optical, capacitive, eddy current and microwave measuring principle. Pressure sensors has been also tried. This paper summarizes the results achieved using a novel instrumentation based on the magnetoresistive sensing elements. The characterization of the novel probe has been already published. The measurement system was validated in test benches and in a real jet-engine comparing different sensor technologies. The whole instrumentation was improved. The work presented in this paper focuses on the current developments. In particular, attention is given to the data processing software and new sensor configurations.

  12. Photothermal speckle modulation for noncontact materials characterization.

    PubMed

    Stolyarov, Alexander M; Sullenberger, Ryan M; Crompton, David R; Jeys, Thomas H; Saar, Brian G; Herzog, William D

    2015-12-15

    We have developed a noncontact, photothermal materials characterization method based on visible-light speckle imaging. This technique is applied to remotely measure the infrared absorption spectra of materials and to discriminate materials based on their thermal conductivities. A wavelength-tunable (7.5-8.7 μm), intensity-modulated, quantum cascade pump laser and a continuous-wave 532 nm probe laser illuminate a sample surface such that the two laser spots overlap. Surface absorption of the intensity-modulated pump laser induces a time-varying thermoelastic surface deformation, resulting in a time-varying 532 nm scattering speckle field from the surface. The speckle modulation amplitude, derived from a series of visible camera images, is found to correlate with the amplitude of the surface motion. By tuning the pump laser's wavelength over a molecular absorption feature, the amplitude spectrum of the speckle modulation is found to correlate to the IR absorption spectrum. As an example, we demonstrate this technique for spectroscopic identification of thin polymeric films. Furthermore, by adjusting the rate of modulation of the pump beam and measuring the associated modulation transfer to the visible speckle pattern, information about the thermal time constants of surface and sub-surface features can be revealed. Using this approach, we demonstrate the ability to distinguish between different materials (including metals, semiconductors, and insulators) based on differences in their thermal conductivities. PMID:26670512

  13. [Noncontact and noninvasive microwave biological measurements].

    PubMed

    Misawa, T; Kutsumi, Y; Tada, H; Kim, S S; Nakai, T; Miyabo, S; Hamada, T; Arai, I; Suzuki, T

    1990-01-01

    Without contact probes, the signals of small human body surface movements were obtained with microwave Doppler sensors using a two-phase interferometric method. The signals were then compared with mechanocardiographic records routinely obtained by contact transducers. Furthermore, this system was applied to patients wearing clothes. The study subjects consisted of 20 cardiac patients and 10 normal controls. 1. The microwave signals obtained in the cervical and precordial regions were similar to those of the mechanocardiographic recordings, such as the carotid pulse and jugular venous pulse tracings and the apexcardiogram. There was a significant correlation between left ventricular ejection time (LVET) obtained by microwave Doppler sensors and that by the carotid pulse tracing (r = 0.95). 2. The signals of the microwave Doppler sensor were obtained from the patients wearing clothes. The heart beat components were distinguished from respiratory motion and patients' movements using band-pass filters. These results suggest that this method is capable of evaluating cardiac function noninvasively and thus has a distinct advantage in the field of non-contact measurements.

  14. Investigation of a noncontact strain measurement technique

    SciTech Connect

    Damiano, B.; Talarico, L.J.

    1996-05-01

    The goal of this project was to investigate the feasibility of a new noncontact technique for directly and continuously monitoring peak strain in rotating components. The technique utilizes the unique strain-sensitive magnetic material properties of transformation Induced Plasticity (TRIP) steel alloys to measure strain. These alloys are weakly magnetic when unstrained but become strongly ferromagnetic after mechanical deformation. A computer study was performed to determine whether the strain-induced change in the magnetic material properties of a TRIP steel gage bonded to a rotating component would cause significant perturbations in the magnetic flux of a stationary electromagnet. The effects of strain level, distance between the rotating component and the stationary electromagnet, and motion-induced eddy currents on flux perturbation magnitude were investigated. The calculated results indicate that a TRIP steel strain sensing element can cause a significant perturbation in the magnetic flux of a stationary electromagnet. The magnetic flux perturbation magnitude was found to be inversely proportional to the distance between the magnet face and the TRIP steel element and directly proportional to the TRIP steel strain level. The effect of motion-induced eddy currents on the magnetic flux was found to be negligible. It appears that the technique can be successfully applied to measure peak strain in rotating components; however, the sensitivity of the magnetic flux perturbation magnitude to the distance between the strain sensing element and the electromagnet may require making an independent proximity measurement.

  15. Noncontact blood perfusion mapping in clinical applications

    NASA Astrophysics Data System (ADS)

    Iakovlev, Dmitry; Dwyer, Vincent; Hu, Sijung; Silberschmidt, Vadim

    2016-04-01

    Non-contact imaging photoplethysmography (iPPG) to detect pulsatile blood microcirculation in tissue has been selected as a successor to low spatial resolution and slow scanning blood perfusion techniques currently employed by clinicians. The proposed iPPG system employs a novel illumination source constructed of multiple high power LEDs with narrow spectral emission, which are temporally modulated and synchronised with a high performance sCMOS sensor. To ensure spectrum stability and prevent thermal wavelength drift due to junction temperature variations, each LED features a custom-designed thermal management system to effectively dissipate generated heat and auto-adjust current flow. The use of a multi-wavelength approach has resulted in simultaneous microvascular perfusion monitoring at various tissue depths, which is an added benefit for specific clinical applications. A synchronous detection algorithm to extract weak photoplethysmographic pulse-waveforms demonstrated robustness and high efficiency when applied to even small regions of 5 mm2. The experimental results showed evidences that the proposed system could achieve noticeable accuracy in blood perfusion monitoring by creating complex amplitude and phase maps for the tissue under examination.

  16. Acoustic enhancement for photo detecting devices

    DOEpatents

    Thundat, Thomas G; Senesac, Lawrence R; Van Neste, Charles W

    2013-02-19

    Provided are improvements to photo detecting devices and methods for enhancing the sensitivity of photo detecting devices. A photo detecting device generates an electronic signal in response to a received light pulse. An electro-mechanical acoustic resonator, electrically coupled to the photo detecting device, damps the electronic signal and increases the signal noise ratio (SNR) of the electronic signal. Increased photo detector standoff distances and sensitivities will result.

  17. Theoretical analysis of dynamic property for piezoelectric cantilever triple-layer benders with large piezoelectric and electromechanical coupling coefficients

    NASA Astrophysics Data System (ADS)

    Gong, Li Jiao; Pan, Cheng Liang; Pan, Qiao Sheng; Feng, Zhi Hua

    2016-06-01

    Ferroelectric single crystals, such as PZN-PT, provide novel prospects in piezoelectric bending devices such as actuators, sensors or energy harvesters because of their extraordinarily large piezoelectric coefficients. However, large errors may occur in some analyses on electromechanical behaviors using the conventional models. We find the bending rigidity of piezoelectric composited bender is affected not only by thickness, width and the modulus of elasticity of the different layers but also electromechanical coupling coefficients (EMCCs) of the piezoelectric material and the larger EMCCs mean more marked effect. This paper focuses on the derivation of the applied input excitation and output response characteristics in the circular frequency domain for piezoelectric cantilever triple-layer benders (PCTBs), taking into account the secondary piezoelectric effect. Analytic dynamic descriptions of such actuators and transducers are obtained. Based on the presented models dynamic features of PCTB composed of PZN-8%PT are calculated, and numerical results coincide with simulations using the finite element method (FEM).

  18. Mobile Cloud-Computing-Based Healthcare Service by Noncontact ECG Monitoring

    PubMed Central

    Fong, Ee-May; Chung, Wan-Young

    2013-01-01

    Noncontact electrocardiogram (ECG) measurement technique has gained popularity these days owing to its noninvasive features and convenience in daily life use. This paper presents mobile cloud computing for a healthcare system where a noncontact ECG measurement method is employed to capture biomedical signals from users. Healthcare service is provided to continuously collect biomedical signals from multiple locations. To observe and analyze the ECG signals in real time, a mobile device is used as a mobile monitoring terminal. In addition, a personalized healthcare assistant is installed on the mobile device; several healthcare features such as health status summaries, medication QR code scanning, and reminders are integrated into the mobile application. Health data are being synchronized into the healthcare cloud computing service (Web server system and Web server dataset) to ensure a seamless healthcare monitoring system and anytime and anywhere coverage of network connection is available. Together with a Web page application, medical data are easily accessed by medical professionals or family members. Web page performance evaluation was conducted to ensure minimal Web server latency. The system demonstrates better availability of off-site and up-to-the-minute patient data, which can help detect health problems early and keep elderly patients out of the emergency room, thus providing a better and more comprehensive healthcare cloud computing service. PMID:24316562

  19. Mobile cloud-computing-based healthcare service by noncontact ECG monitoring.

    PubMed

    Fong, Ee-May; Chung, Wan-Young

    2013-01-01

    Noncontact electrocardiogram (ECG) measurement technique has gained popularity these days owing to its noninvasive features and convenience in daily life use. This paper presents mobile cloud computing for a healthcare system where a noncontact ECG measurement method is employed to capture biomedical signals from users. Healthcare service is provided to continuously collect biomedical signals from multiple locations. To observe and analyze the ECG signals in real time, a mobile device is used as a mobile monitoring terminal. In addition, a personalized healthcare assistant is installed on the mobile device; several healthcare features such as health status summaries, medication QR code scanning, and reminders are integrated into the mobile application. Health data are being synchronized into the healthcare cloud computing service (Web server system and Web server dataset) to ensure a seamless healthcare monitoring system and anytime and anywhere coverage of network connection is available. Together with a Web page application, medical data are easily accessed by medical professionals or family members. Web page performance evaluation was conducted to ensure minimal Web server latency. The system demonstrates better availability of off-site and up-to-the-minute patient data, which can help detect health problems early and keep elderly patients out of the emergency room, thus providing a better and more comprehensive healthcare cloud computing service. PMID:24316562

  20. Mobile cloud-computing-based healthcare service by noncontact ECG monitoring.

    PubMed

    Fong, Ee-May; Chung, Wan-Young

    2013-12-02

    Noncontact electrocardiogram (ECG) measurement technique has gained popularity these days owing to its noninvasive features and convenience in daily life use. This paper presents mobile cloud computing for a healthcare system where a noncontact ECG measurement method is employed to capture biomedical signals from users. Healthcare service is provided to continuously collect biomedical signals from multiple locations. To observe and analyze the ECG signals in real time, a mobile device is used as a mobile monitoring terminal. In addition, a personalized healthcare assistant is installed on the mobile device; several healthcare features such as health status summaries, medication QR code scanning, and reminders are integrated into the mobile application. Health data are being synchronized into the healthcare cloud computing service (Web server system and Web server dataset) to ensure a seamless healthcare monitoring system and anytime and anywhere coverage of network connection is available. Together with a Web page application, medical data are easily accessed by medical professionals or family members. Web page performance evaluation was conducted to ensure minimal Web server latency. The system demonstrates better availability of off-site and up-to-the-minute patient data, which can help detect health problems early and keep elderly patients out of the emergency room, thus providing a better and more comprehensive healthcare cloud computing service.

  1. Transient modeling of electromechanical relays. Part 2: Plunger type 50 relays

    SciTech Connect

    Glinkowski, M.T.; Esztergalyos, J.

    1996-04-01

    Electromechanical, plunger type 50 relay is modeled in EMTP/ATP using TACS. Mechanical magnetic, and electrical characteristics are represented in the form of simple mathematical models that can provide a useful tool for studying the dynamic responses of the Type 50 devices and incorporating them into a power system transient analysis. This paper is the second part of a summary report by Rensselaer Polytechnic Institute (RPI) of work on relay modeling sponsored by the Bonneville Power Administration (BPA). Part 2 presents the Electro-Magnetic Transient Program/Alternative Transient Program (EMTP/ATP) model for plunger type 50 instantaneous overcurrent relays that compare with actual tests performed on the devices on a Power System Simulator (PSS).

  2. Electromechanical instabilities of thermoplastics: Theory and in situ observation.

    PubMed

    Wang, Qiming; Niu, Xiaofan; Pei, Qibing; Dickey, Michael D; Zhao, Xuanhe

    2012-10-01

    Thermoplastics under voltages are used in diverse applications ranging from insulating cables to organic capacitors. Electromechanical instabilities have been proposed as a mechanism that causes electrical breakdown of thermoplastics. However, existing experiments cannot provide direct observations of the instability process, and existing theories for the instabilities generally assume thermoplastics are mechanically unconstrained. Here, we report in situ observations of electromechanical instabilities in various thermoplastics. A theory is formulated for electromechanical instabilities of thermoplastics under different mechanical constraints. We find that the instabilities generally occur in thermoplastics when temperature is above their glass transition temperatures and electric field reaches a critical value. The critical electric field for the instabilities scales with square root of yield stress of the thermoplastic and depends on its Young's modulus and hardening property.

  3. Non-contact Laser-based Human Respiration Rate Measurement

    NASA Astrophysics Data System (ADS)

    Scalise, L.; Marchionni, P.; Ercoli, I.

    2011-08-01

    At present the majority of the instrumentation, used in clinical environments, to measure human respiration rate are based on invasive and contact devices. The gold standard instrument is considered the spirometer which is largely used; it needs a direct contact and requires a collaboration by the patient. Laser Doppler Vibrometer (LDVi) is an optical, non-contact measurement system for the assessment of a surface velocity and displacement. LDVi has already been used for the measurement of the cardiac activity and for the measurement of the chest-wall displacements. The aims of this work are to select the best measurement point on the thoracic surface for LDVi monitoring of the respiration rate (RR) and to compare measured data with the RR valued provided by the spirometer. The measurement system is composed by a LDV system and a data acquisition board installed on a PC. Tests were made on 10 different point of the thorax for each patient. Patients population was composed by 33 subjects (17 male and 16 female). The optimal measurement point was chosen considering the maximum peak-to-peak value of the displacement measured by LDV. Before extracting RR we have used a special wavelet decomposition for better selection of the expiration peaks. A standard spirometer was used for the validation of the data. From tests it results that the optimal measurement point, namely is located on the inferior part of the thoracic region (left, front side). From our tests we have obtained a close correlation between the RR values measured by the spirometer and those measured by the proposed method: a difference of 14±211 ms on the RR value is reported for the entire population of 33 subjects. Our method allows a no-contact measurement of lungs activity (respiration period), reducing the electric and biological risks. Moreover it allows to measure in critical environment like in RMN or in burned skin where is difficult or impossible to apply electrodes.

  4. Electromechanical actuation for thrust vector control applications

    NASA Astrophysics Data System (ADS)

    Roth, Mary Ellen

    At present, actuation systems for the Thrust Vector Control (TVC) for launch vehicles are hydraulic systems. The Advanced Launch System (ALS), a joint initiative between NASA and the Air Force, is a launch vehicle that is designed to be cost effective, highly reliable and operationally efficient with a goal of reducing the cost per pound to orbit. As part of this initiative, an electromechanical actuation system is being developed as an attractive alternative to the hydraulic systems used today. NASA-Lewis is developing and demonstrating an Induction Motor Controller Actuation System with a 40 hp peak rating. The controller will integrate 20 kHz resonant link Power Management and Distribution (PMAD) technology and Pulse Population Modulation (PPM) techniques to implement Field Oriented Vector Control (FOVC) of a new advanced induction motor. Through PPM, multiphase variable frequency, variable voltage waveforms can be synthesized from the 20 kHz source. FOVC shows that varying both the voltage and frequency and their ratio (V/F), permits independent control of both torque and speed while operating at maximum efficiency at any point on the torque-speed curve. The driver and the FOVC will be microprocessor controlled. For increased system reliability, a Built-in Test (BITE) capability will be included. This involves introducing testability into the design of a system such that testing is calibrated and exercised during the design, manufacturing, maintenance and prelaunch activities. An actuator will be integrated with the motor controller for performance testing of the EMA TVC system. The design and fabrication of the motor controller is being done by General Dynamics Space Systems Division. The University of Wisconsin-Madison will assist in the design of the advanced induction motor and in the implementation of the FOVC theory. A 75 hp electronically controlled dynamometer will be used to test the motor controller in all four quadrants of operation using flight type

  5. Parallel FEM Simulation of Electromechanics in the Heart

    NASA Astrophysics Data System (ADS)

    Xia, Henian; Wong, Kwai; Zhao, Xiaopeng

    2011-11-01

    Cardiovascular disease is the leading cause of death in America. Computer simulation of complicated dynamics of the heart could provide valuable quantitative guidance for diagnosis and treatment of heart problems. In this paper, we present an integrated numerical model which encompasses the interaction of cardiac electrophysiology, electromechanics, and mechanoelectrical feedback. The model is solved by finite element method on a Linux cluster and the Cray XT5 supercomputer, kraken. Dynamical influences between the effects of electromechanics coupling and mechanic-electric feedback are shown.

  6. Coupling of the electrocaloric and electromechanical effects for solid-state refrigeration

    NASA Astrophysics Data System (ADS)

    Bradeško, A.; Juričić, Äń.; Santo Zarnik, M.; Malič, B.; Kutnjak, Z.; Rojac, T.

    2016-10-01

    Electrocaloric (EC) materials have shown the potential to replace some of the technologies in current commercial refrigeration systems. The key problem when fabricating an efficient EC refrigerator is the small adiabatic temperature change that current bulk materials can achieve. Therefore, such a solid-state EC refrigerator should be engineered to enhance the EC temperature change by rectifying the induced EC heat flow. Here, we present a numerical study of a device that couples the EC and electromechanical (EM) effects in a single active material. The device consists of several elements made from a functional material with coupled EC and EM properties, allowing the elements to bend and change their temperature with the application of an electric field. The periodic excitation of these elements results in a temperature span across the device. By assuming heat exchange with the environment and a low thermal contact resistivity between the elements, we show that a device with 15 elements and an EC effect of 1.2 K achieves a temperature span between the hot and cold sides of the device equal to 12.6 K. Since the temperature span can be controlled by the number of elements in the device, the results suggest that in combination with the so-called "giant" EC effect (ΔTEC ≥ 10 K), a very large temperature span would be possible. The results of this work should motivate the development of efficient EC refrigeration systems based on a coupling of the EC and EM effects.

  7. High resolution non-contact interior profilometer

    DOEpatents

    Piltch, Martin S.; Patterson, R. Alan; Leeches, Gerald W.; Nierop, John Van; Teti, John J.

    2001-01-01

    Apparatus and method for inspecting the interior surfaces of devices such as vessels having a single entry port. Laser energy is launched into the vessel, and the light reflected from the interior surfaces is interfered with reference laser energy to produce an interference pattern. This interference pattern is analyzed to reveal information about the condition of the interior surfaces of the device inspected.

  8. Non-contact optical sensor for detection of glucose concentration using a magneto-optic effect

    NASA Astrophysics Data System (ADS)

    Ozana, Nisan; Beiderman, Yevgeny; Anand, Arun; Javidi, Baharam; Polani, Sagi; Schwarz, Ariel; Shemer, Amir; García, Javier; Zalevsky, Zeev

    2016-03-01

    In this paper we aim to experimentally verify a speckle based technique for non-contact measurement of glucose concentration in blood stream while the vision for the final device aims to contain a single wristwatch-style device containing an AC (alternating) electro-magnet generated by a solenoid, a laser and a camera. The experiments presented in work are performed in-vitro in order to verify the effects that are responsible for the operation principle. When a glucose substance is inserted into a solenoid generating an alternating magnetic field it exhibits Faraday rotation which affects the temporal changes of the secondary speckle patterns distribution. The temporal frequency resulting from the AC magnetic field was found to have a lock-in amplification role which increased the observability of the relatively small magneto-optic effect. Experimental results to support the proposed concept are presented.

  9. Noncontact speckle-based optical sensor for detection of glucose concentration using magneto-optic effect

    NASA Astrophysics Data System (ADS)

    Ozana, Nisan; Beiderman, Yevgeny; Anand, Arun; Javidi, Baharam; Polani, Sagi; Schwarz, Ariel; Shemer, Amir; Garcia, Javier; Zalevsky, Zeev

    2016-06-01

    We experimentally verify a speckle-based technique for noncontact measurement of glucose concentration in the bloodstream. The final device is intended to be a single wristwatch-style device containing a laser, a camera, and an alternating current (ac) electromagnet generated by a solenoid. The experiments presented are performed in vitro as proof of the concept. When a glucose substance is inserted into a solenoid generating an ac magnetic field, it exhibits Faraday rotation, which affects the temporal changes of the secondary speckle pattern distributions. The temporal frequency resulting from the ac magnetic field was found to have a lock-in amplification role, which increased the observability of the relatively small magneto-optic effect. Experimental results to support the proposed concept are presented.

  10. Solid state lasers for use in non-contact temperature measurements

    NASA Technical Reports Server (NTRS)

    Buoncristiani, A. M.

    1989-01-01

    The last decade has seen a series of dramatic developments in solid state laser technology. Prominent among these has been the emergence of high power semiconductor laser diode arrays and a deepening understanding of the dynamics of solid state lasers. Taken in tandem these two developments enable the design of laser diode pumped solid state lasers. Pumping solid state lasers with semiconductor diodes relieves the need for cumbersome and inefficient flashlamps and results in an efficient and stable laser with the compactness and reliability. It provides a laser source that can be reliably used in space. These new coherent sources are incorporated into the non-contact measurement of temperature. The primary focus is the development and characterization of new optical materials for use in active remote sensors of the atmosphere. In the course of this effort several new materials and new concepts were studied which can be used for other sensor applications. The general approach to the problem of new non-contact temperature measurements has had two components. The first component centers on passive sensors using optical fibers; an optical fiber temperature sensor for the drop tube was designed and tested at the Marshall Space Flight Center. Work on this problem has given insight into the use of optical fibers, especially new IR fibers, in thermal metrology. The second component of the effort is to utilize the experience gained in the study of passive sensors to examine new active sensor concepts. By active sensor are defined as a sensing device or mechanism which is interrogated in some way be radiation, usually from a laser. The status of solid state lasers as sources for active non-contact temperature sensors are summarized. Some specific electro-optic techniques are described which are applicable to the sensor problems at hand. Work on some of these ideas is in progress while other concepts are still being worked out.

  11. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Electromechanical interlocking machine; locking... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical interlocking machine, locking between electric and mechanical levers shall be maintained so that...

  12. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Electromechanical interlocking machine; locking... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical interlocking machine, locking between electric and mechanical levers shall be maintained so that...

  13. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Electromechanical interlocking machine; locking... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical interlocking machine, locking between electric and mechanical levers shall be maintained so that...

  14. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Electromechanical interlocking machine; locking... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical interlocking machine, locking between electric and mechanical levers shall be maintained so that...

  15. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Electromechanical interlocking machine; locking... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical interlocking machine, locking between electric and mechanical levers shall be maintained so that...

  16. The electromechanical behavior of a micro-ring driven by traveling electrostatic force.

    PubMed

    Ye, Xiuqian; Chen, Yibao; Chen, Da-Chih; Huang, Kuo-Yi; Hu, Yuh-Chung

    2012-01-01

    There is no literature mentioning the electromechanical behavior of micro structures driven by traveling electrostatic forces. This article is thus the first to present the dynamics and stabilities of a micro-ring subjected to a traveling electrostatic force. The traveling electrostatic force may be induced by sequentially actuated electrodes which are arranged around the flexible micro-ring. The analysis is based on a linearized distributed model considering the electromechanical coupling effects between electrostatic force and structure. The micro-ring will resonate when the traveling speeds of the electrostatic force approach some critical speeds. The critical speeds are equal to the ratio of the natural frequencies to the wave number of the correlative natural mode of the ring. Apart from resonance, the ring may be unstable at some unstable traveling speeds. The unstable regions appear not only near the critical speeds, but also near some fractions of some critical speeds differences. Furthermore the unstable regions expand with increasing driving voltage. This article may lead to a new research branch on electrostatic-driven micro devices.

  17. Electromechanical control of nitrogen-vacancy defect emission using graphene NEMS

    PubMed Central

    Reserbat-Plantey, Antoine; Schädler, Kevin G.; Gaudreau, Louis; Navickaite, Gabriele; Güttinger, Johannes; Chang, Darrick; Toninelli, Costanza; Bachtold, Adrian; Koppens, Frank H. L.

    2016-01-01

    Despite recent progress in nano-optomechanics, active control of optical fields at the nanoscale has not been achieved with an on-chip nano-electromechanical system (NEMS) thus far. Here we present a new type of hybrid system, consisting of an on-chip graphene NEMS suspended a few tens of nanometres above nitrogen-vacancy centres (NVCs), which are stable single-photon emitters embedded in nanodiamonds. Electromechanical control of the photons emitted by the NVC is provided by electrostatic tuning of the graphene NEMS position, which is transduced to a modulation of NVC emission intensity. The optomechanical coupling between the graphene displacement and the NVC emission is based on near-field dipole–dipole interaction. This class of optomechanical coupling increases strongly for smaller distances, making it suitable for nanoscale devices. These achievements hold promise for selective control of emitter arrays on-chip, optical spectroscopy of individual nano-objects, integrated optomechanical information processing and open new avenues towards quantum optomechanics. PMID:26742541

  18. Noncontacting thermoelectric detection of material imperfections in metals

    SciTech Connect

    Peter B. Nagy; Adnan H. Nayfeh; Waseem I. Faidi; Hector Carreon; Balachander Lakshminaraya; Feng Yu; Bassam Abu-Nabah

    2005-06-17

    This project was aimed at developing a new noncontacting thermoelectric method for nondestructive detection of material imperfections in metals. The method is based on magnetic sensing of local thermoelectric currents around imperfections when a temperature gradient is established throughout a conducting specimen by external heating and cooling. The surrounding intact material serves as the reference electrode therefore the detection sensitivity could be very high if a sufficiently sensitive magnetometer is used in the measurements. This self-referencing, noncontacting, nondestructive inspection technique offers the following distinct advantages over conventional methods: high sensitivity to subtle variations in material properties, unique insensitivity to the size, shape, and other geometrical features of the specimen, noncontacting nature with a substantial stand-off distance, and the ability to probe relatively deep into the material. The potential applications of this method cover a very wide range from detection metallic inclusions and segregations, inhomogeneities, and tight cracks to characterization of hardening, embrittlement, fatigue, texture, and residual stresses.

  19. A Variational Approach to the Analysis of Dissipative Electromechanical Systems

    PubMed Central

    Allison, Andrew; Pearce, Charles E. M.; Abbott, Derek

    2014-01-01

    We develop a method for systematically constructing Lagrangian functions for dissipative mechanical, electrical, and electromechanical systems. We derive the equations of motion for some typical electromechanical systems using deterministic principles that are strictly variational. We do not use any ad hoc features that are added on after the analysis has been completed, such as the Rayleigh dissipation function. We generalise the concept of potential, and define generalised potentials for dissipative lumped system elements. Our innovation offers a unified approach to the analysis of electromechanical systems where there are energy and power terms in both the mechanical and electrical parts of the system. Using our novel technique, we can take advantage of the analytic approach from mechanics, and we can apply these powerful analytical methods to electrical and to electromechanical systems. We can analyse systems that include non-conservative forces. Our methodology is deterministic, and does does require any special intuition, and is thus suitable for automation via a computer-based algebra package. PMID:24586221

  20. Electromechanical Teaching Toys for Infants and Toddlers with Disabilities.

    ERIC Educational Resources Information Center

    Hanline, Mary Frances; And Others

    1985-01-01

    The article describes the use and design of several electromechanical toys that provide motivation, reinforcement, feedback, and contingent consequences to disabled infants and toddlers. Illustrations and explanations are offered for weight bearing boards, responsive puzzles, reach and grasp wheels, body parts teaching dolls, and kickpanels. (CL)

  1. Electromechanical hand incorporates touch sensors and trigger function

    NASA Technical Reports Server (NTRS)

    Dane, D. H.

    1970-01-01

    Electromechanical hand incorporates touch sensors, concealed fingers, and a structure that allows the hand to hold a tool on a flat surface. The hands can be mounted on most types of existing manipulators either directly or by means of modified mounting brackets.

  2. Combined electromechanical impedance and fiber optic diagnosis of aerospace structures

    NASA Astrophysics Data System (ADS)

    Schlavin, Jon; Zagrai, Andrei; Clemens, Rebecca; Black, Richard J.; Costa, Joey; Moslehi, Behzad; Patel, Ronak; Sotoudeh, Vahid; Faridian, Fereydoun

    2014-03-01

    Electromechanical impedance is a popular diagnostic method for assessing structural conditions at high frequencies. It has been utilized, and shown utility, in aeronautic, space, naval, civil, mechanical, and other types of structures. By contrast, fiber optic sensing initially found its niche in static strain measurement and low frequency structural dynamic testing. Any low frequency limitations of the fiber optic sensing, however, are mainly governed by its hardware elements. As hardware improves, so does the bandwidth (frequency range * number of sensors) provided by the appropriate enabling fiber optic sensor interrogation system. In this contribution we demonstrate simultaneous high frequency measurements using fiber optic and electromechanical impedance structural health monitoring technologies. A laboratory specimen imitating an aircraft wing structure, incorporating surfaces with adjustable boundary conditions, was instrumented with piezoelectric and fiber optic sensors. Experiments were conducted at different structural boundary conditions associated with deterioration of structural health. High frequency dynamic responses were collected at multiple locations on a laboratory wing specimen and conclusions were drawn about correspondence between structural damage and dynamic signatures as well as correlation between electromechanical impedance and fiber optic sensors spectra. Theoretical investigation of the effect of boundary conditions on electromechanical impedance spectra is presented and connection to low frequency structural dynamics is suggested. It is envisioned that acquisition of high frequency structural dynamic responses with multiple fiber optic sensors may open new diagnostic capabilities for fiber optic sensing technologies.

  3. Mechanical impedance measurement and damage detection using noncontact laser ultrasound.

    PubMed

    Lee, Hyeonseok; Lim, Hyeong Uk; Hong, Jung-Wuk; Sohn, Hoon

    2014-06-01

    This Letter proposes a mechanical impedance (MI) measurement technique using noncontact laser ultrasound. The ultrasound is generated by shooting a pulse laser beam onto a target structure, and its response is measured using a laser vibrometer. Once ultrasound propagation converges to structural vibration, MI is formed over the entire structure. Because noncontact lasers are utilized, this technique is applicable in harsh environments, free of electromagnetic interference, and able to perform wide-range scanning. The formation of MI and its feasibility for damage detection are verified through thermo-mechanical finite element analysis and lab-scale experiments.

  4. [The non-contact effect of substances containing benzene rings and heterocycles on biological systems].

    PubMed

    Frolov, Iu P

    2001-01-01

    It was found that some substances containing benzolic rings and heterocyclic structures have a noncontact effect on biosystems. Some results of experiments dealing with the noncontact effect on enzyme molecules, cells, and uni- and multicellular organisms are presented. Factors influencing the efficiency of the noncontact effect were revealed. PMID:11605403

  5. Fast on-wafer electrical, mechanical, and electromechanical characterization of piezoresistive cantilever force sensors.

    PubMed

    Tosolini, G; Villanueva, L G; Perez-Murano, F; Bausells, J

    2012-01-01

    Validation of a technological process requires an intensive characterization of the performance of the resulting devices, circuits, or systems. The technology for the fabrication of micro and nanoelectromechanical systems (MEMS and NEMS) is evolving rapidly, with new kind of device concepts for applications like sensing or harvesting are being proposed and demonstrated. However, the characterization tools and methods for these new devices are still not fully developed. Here, we present an on-wafer, highly precise, and rapid characterization method to measure the mechanical, electrical, and electromechanical properties of piezoresistive cantilevers. The setup is based on a combination of probe-card and atomic force microscopy technology, it allows accessing many devices across a wafer and it can be applied to a broad range of MEMS and NEMS. Using this setup we have characterized the performance of multiple submicron thick piezoresistive cantilever force sensors. For the best design we have obtained a force sensitivity Re(F) = 158μV/nN, a noise of 5.8 μV (1 Hz-1 kHz) and a minimum detectable force of 37 pN with a relative standard deviation of σ(r) ≈ 8%. This small value of σ(r), together with a high fabrication yield >95%, validates our fabrication technology. These devices are intended to be used as bio-molecular detectors for the measurement of intermolecular forces between ligand and receptor molecule pairs.

  6. The non-contact heart rate measurement system for monitoring HRV.

    PubMed

    Huang, Ji-Jer; Yu, Sheng-I; Syu, Hao-Yi; See, Aaron Raymond

    2013-01-01

    A noncontact ECG monitoring and analysis system was developed using capacitive-coupled device integrated to a home sofa. Electrodes were placed on the backrest of a sofa separated from the body with only the chair covering and the user's clothing. The study also incorporates measurements using different fabric materials, and a pure cotton material was chosen to cover the chair's backrest. The material was chosen to improve the signal to noise ratio. The system is initially implemented on a home sofa and is able to measure non-contact ECG through thin cotton clothing and perform heart rate analysis to calculate the heart rate variability (HRV) parameters. It was also tested under different conditions and results from reading and sleeping exhibited a stable ECG. Subsequently, results from our calculated HRV were found to be identical to those of a commercially available HRV analyzer. However, HRV parameters are easily affected by motion artifacts generated during drinking or eating with the latter producing a more severe disturbance. Lastly, parameters measured are saved on a cloud database, providing users with a long-term monitoring and recording for physiological information.

  7. A high-stability non-contact dilatometer for low-amplitude temperature-modulated measurements.

    PubMed

    Luckabauer, Martin; Sprengel, Wolfgang; Würschum, Roland

    2016-07-01

    Temperature modulated thermophysical measurements can deliver valuable insights into the phase transformation behavior of many different materials. While especially for non-metallic systems at low temperatures numerous powerful methods exist, no high-temperature device suitable for modulated measurements of bulk metallic alloy samples is available for routine use. In this work a dilatometer for temperature modulated isothermal and non-isothermal measurements in the temperature range from room temperature to 1300 K is presented. The length measuring system is based on a two-beam Michelson laser interferometer with an incremental resolution of 20 pm. The non-contact measurement principle allows for resolving sinusoidal length change signals with amplitudes in the sub-500 nm range and physically decouples the length measuring system from the temperature modulation and heating control. To demonstrate the low-amplitude capabilities, results for the thermal expansion of nickel for two different modulation frequencies are presented. These results prove that the novel method can be used to routinely resolve length-change signals of metallic samples with temperature amplitudes well below 1 K. This high resolution in combination with the non-contact measurement principle significantly extends the application range of modulated dilatometry towards high-stability phase transformation measurements on complex alloys.

  8. A high-stability non-contact dilatometer for low-amplitude temperature-modulated measurements.

    PubMed

    Luckabauer, Martin; Sprengel, Wolfgang; Würschum, Roland

    2016-07-01

    Temperature modulated thermophysical measurements can deliver valuable insights into the phase transformation behavior of many different materials. While especially for non-metallic systems at low temperatures numerous powerful methods exist, no high-temperature device suitable for modulated measurements of bulk metallic alloy samples is available for routine use. In this work a dilatometer for temperature modulated isothermal and non-isothermal measurements in the temperature range from room temperature to 1300 K is presented. The length measuring system is based on a two-beam Michelson laser interferometer with an incremental resolution of 20 pm. The non-contact measurement principle allows for resolving sinusoidal length change signals with amplitudes in the sub-500 nm range and physically decouples the length measuring system from the temperature modulation and heating control. To demonstrate the low-amplitude capabilities, results for the thermal expansion of nickel for two different modulation frequencies are presented. These results prove that the novel method can be used to routinely resolve length-change signals of metallic samples with temperature amplitudes well below 1 K. This high resolution in combination with the non-contact measurement principle significantly extends the application range of modulated dilatometry towards high-stability phase transformation measurements on complex alloys. PMID:27475604

  9. A high-stability non-contact dilatometer for low-amplitude temperature-modulated measurements

    NASA Astrophysics Data System (ADS)

    Luckabauer, Martin; Sprengel, Wolfgang; Würschum, Roland

    2016-07-01

    Temperature modulated thermophysical measurements can deliver valuable insights into the phase transformation behavior of many different materials. While especially for non-metallic systems at low temperatures numerous powerful methods exist, no high-temperature device suitable for modulated measurements of bulk metallic alloy samples is available for routine use. In this work a dilatometer for temperature modulated isothermal and non-isothermal measurements in the temperature range from room temperature to 1300 K is presented. The length measuring system is based on a two-beam Michelson laser interferometer with an incremental resolution of 20 pm. The non-contact measurement principle allows for resolving sinusoidal length change signals with amplitudes in the sub-500 nm range and physically decouples the length measuring system from the temperature modulation and heating control. To demonstrate the low-amplitude capabilities, results for the thermal expansion of nickel for two different modulation frequencies are presented. These results prove that the novel method can be used to routinely resolve length-change signals of metallic samples with temperature amplitudes well below 1 K. This high resolution in combination with the non-contact measurement principle significantly extends the application range of modulated dilatometry towards high-stability phase transformation measurements on complex alloys.

  10. A review of non-contact, low-cost physiological information measurement based on photoplethysmographic imaging.

    PubMed

    Liu, He; Wang, Yadong; Wang, Lei

    2012-01-01

    In recent decades, there has been increasing interest in low-cost, non-contact and pervasive methods for measuring physiological information, such as heart rate (HR), respiratory rate, heart rate variability (HRV) and oxyhemoglobin saturation. The conventional methods including wet adhesive Ag/AgCl electrodes for HR and HRV, the capnograph device for respiratory status and pulse oximetry for oxyhemoglobin saturation provide excellent signals but are expensive, troublesome and inconvenient. A method to monitor physiological information based on photoplethysmographic imaging offers a new means for health monitoring. Blood volume can be indirectly assessed in terms of blood velocity, blood flow rate and blood pressure, which, in turn, can reflect changes in physiological parameters. Changes in blood volume can be determined from the spectra of light reflected from or transmitted through body tissues. Images of an area of the skin surface are consecutively captured with the color camera of a computer or smartphone and, by processing and analyzing the light signals, physiological information such as HR, respiratory rate, HRV and oxyhemoglobin saturation can be acquired. In this paper, we review the latest developments in using photoplethysmographic imaging for non-contact health monitoring and discuss the challenges and future directions for this field. PMID:23366332

  11. A Study of a Handrim-Activated Power-Assist Wheelchair Based on a Non-Contact Torque Sensor

    PubMed Central

    Nam, Ki-Tae; Jang, Dae-Jin; Kim, Yong Chol; Heo, Yoon; Hong, Eung-Pyo

    2016-01-01

    Demand for wheelchairs is increasing with growing numbers of aged and disabled persons. Manual wheelchairs are the most commonly used assistive device for mobility because they are convenient to transport. Manual wheelchairs have several advantages but are not easy to use for the elderly or those who lack muscular strength. Therefore, handrim-activated power-assist wheelchairs (HAPAW) that can aid driving power with a motor by detecting user driving intentions through the handrim are being researched. This research will be on HAPAW that judge user driving intentions by using non-contact torque sensors. To deliver the desired motion, which is sensed from handrim rotation relative to a fixed controller, a new driving wheel mechanism is designed by applying a non-contact torque sensor, and corresponding torques are simulated. Torques are measured by a driving wheel prototype and compared with simulation results. The HAPAW prototype was developed using the wheels and a driving control algorithm that uses left and right input torques and time differences are used to check if the non-contact torque sensor can distinguish users’ driving intentions. Through this procedure, it was confirmed that the proposed sensor can be used effectively in HAPAW. PMID:27509508

  12. A Study of a Handrim-Activated Power-Assist Wheelchair Based on a Non-Contact Torque Sensor.

    PubMed

    Nam, Ki-Tae; Jang, Dae-Jin; Kim, Yong Chol; Heo, Yoon; Hong, Eung-Pyo

    2016-01-01

    Demand for wheelchairs is increasing with growing numbers of aged and disabled persons. Manual wheelchairs are the most commonly used assistive device for mobility because they are convenient to transport. Manual wheelchairs have several advantages but are not easy to use for the elderly or those who lack muscular strength. Therefore, handrim-activated power-assist wheelchairs (HAPAW) that can aid driving power with a motor by detecting user driving intentions through the handrim are being researched. This research will be on HAPAW that judge user driving intentions by using non-contact torque sensors. To deliver the desired motion, which is sensed from handrim rotation relative to a fixed controller, a new driving wheel mechanism is designed by applying a non-contact torque sensor, and corresponding torques are simulated. Torques are measured by a driving wheel prototype and compared with simulation results. The HAPAW prototype was developed using the wheels and a driving control algorithm that uses left and right input torques and time differences are used to check if the non-contact torque sensor can distinguish users' driving intentions. Through this procedure, it was confirmed that the proposed sensor can be used effectively in HAPAW. PMID:27509508

  13. Method and apparatus for non-contact charge measurement

    NASA Technical Reports Server (NTRS)

    Wang, Taylor G. (Inventor); Lin, Kuan-Chan (Inventor); Hightower, James C. (Inventor)

    1994-01-01

    A method and apparatus for the accurate non-contact detection and measurement of static electric charge on an object using a reciprocating sensing probe that moves relative to the object. A monitor measures the signal generated as a result of this cyclical movement so as to detect the electrostatic charge on the object.

  14. Effect of Microstructure on the Electro-Mechanical Behaviour of Cu Films on Polyimide

    NASA Astrophysics Data System (ADS)

    Berger, J.; Glushko, O.; Marx, V. M.; Kirchlechner, C.; Cordill, M. J.

    2016-06-01

    Metal films on polymer substrates are commonly used in flexible electronic devices and may be exposed to large deformations during application. For flexible electronics, the main requirement is to remain conductive while stretching and compressing. Therefore, the electro-mechanical behaviour of 200-nm-thick Cu films on polyimide with two different microstructures (as-deposited and annealed) were studied by executing in situ fragmentation experiments with x-ray diffraction, under an atomic force microscope, and with 4-point probe resistance measurements in order to correlate the plastic deformation with the electrical behaviour. The three in situ techniques clearly demonstrate different behaviours controlled by the microstructure. Interestingly, the as-deposited film with a bi-modal microstructure is more suited for flexible electronic applications than an annealed film with homogenous 1- µm-sized grains. The as-deposited film reaches a higher yield stress, with unchanged electrical conductivity, and does not show extensive surface deformation during straining.

  15. Thin broadband noise absorption through acoustic reactance control by electro-mechanical coupling without sensor.

    PubMed

    Zhang, Yumin; Chan, Yum-Ji; Huang, Lixi

    2014-05-01

    Broadband noise with profound low-frequency profile is prevalent and difficult to be controlled mechanically. This study demonstrates effective broadband sound absorption by reducing the mechanical reactance of a loudspeaker using a shunt circuit through electro-mechanical coupling, which induces reactance with different signs from that of loudspeaker. An RLC shunt circuit is connected to the moving coil to provide an electrically induced mechanical impedance which counters the cavity stiffness at low frequencies and reduces the system inertia above the resonance frequency. A sound absorption coefficient well above 0.5 is demonstrated across frequencies between 150 and 1200 Hz. The performance of the proposed device is superior to existing passive absorbers of the same depth (60 mm), which has lower frequency limits of around 300 Hz. A passive noise absorber is further proposed by paralleling a micro-perforated panel with shunted loudspeaker which shows potentials in absorbing band-limit impulse noise.

  16. Promising future energy storage systems: Nanomaterial based systems, Zn-air, and electromechanical batteries

    NASA Astrophysics Data System (ADS)

    Koopman, R.; Richardson, J.

    1993-10-01

    Future energy storage systems will require longer shelf life, higher duty cycles, higher efficiency, higher energy and power densities, and be fabricated in an environmentally conscious process. This paper describes several possible future systems which have the potential of providing stored energy for future electric and hybrid vehicles. Three of the systems have their origin in the control of material structure at the molecular level and the subsequent nanoengineering into useful device and components: aerocapacitors, nanostructure multilayer capacitors, and the lithium ion battery. The zinc-air battery is a high energy density battery which can provide vehicles with long range (400 km in autos) and be rapidly refueled with a slurry of zinc particles and electrolyte. The electromechanical battery is a battery-sized module containing a high-speed rotor integrated with an iron-less generator mounted on magnetic bearings and housed in an evacuated chamber.

  17. An experimental evaluation of the fully coupled hysteretic electro-mechanical behaviour of piezoelectric actuators

    NASA Astrophysics Data System (ADS)

    Butcher, Mark; Davino, Daniele; Giustiniani, Alessandro; Masi, Alessandro

    2016-04-01

    Piezoelectrics are the most commonly used of the multifunctional smart materials in industrial applications, because of their relatively low cost and ease of use in electric and electronic oriented applications. Nevertheless, while datasheets usually give just small signal quasi-static parameters, their full potential can only be exploited only if a full characterization is available because the maximum stroke or the higher piezo coupling coefficients are available at different electro-mechanical biases, where often small signal analysis is not valid. In this paper a method to get the quasi-static fully coupled characterization is presented. The method is tested on a commercial piezo actuator but can be extended to similar devices.

  18. Promising future energy storage systems: Nanomaterial based systems, Zn-air and electromechanical batteries

    SciTech Connect

    Koopman, R.; Richardson, J.

    1993-10-01

    Future energy storage systems will require longer shelf life, higher duty cycles, higher efficiency, higher energy and power densities, and be fabricated in an environmentally conscious process. This paper describes several possible future systems which have the potential of providing stored energy for future electric and hybrid vehicles. Three of the systems have their origin in the control of material structure at the molecular level and the subsequent nanoengineering into useful device and components: aerocapacitors, nanostructure multilayer capacitors, and the lithium ion battery. The zinc-air battery is a high energy density battery which can provide vehicles with long range (400 km in autos) and be rapidly refueled with a slurry of zinc particles and electrolyte. The electromechanical battery is a battery-sized module containing a high-speed rotor integrated with an iron-less generator mounted on magnetic bearings and housed in an evacuated chamber.

  19. Non-contact optical Liquid Level Sensors

    NASA Astrophysics Data System (ADS)

    Kiseleva, L. L.; Tevelev, L. V.; Shaimukhametov, R. R.

    2016-06-01

    Information about characteristics of the optical liquid level sensor are present. Sensors are used to control of the light level limit fluid - water, kerosene, alcohol, solutions, etc. Intrinsically safe, reliable and easy to use. The operating principle of the level sensor is an optoelectronic infrared device.

  20. Electromechanical transducer for rapid detection, discrimination and quantification of lung cancer cells

    NASA Astrophysics Data System (ADS)

    Ali, Waqas; Jalvhei Moghaddam, Fatemeh; Usman Raza, Muhammad; Bui, Loan; Sayles, Bailey; Kim, Young-Tae; Iqbal, Samir M.

    2016-05-01

    Tumor cells are malignant derivatives of normal cells. There are characteristic differences in the mechanophysical properties of normal and tumor cells, and these differences stem from the changes that occur in the cell cytoskeleton during cancer progression. There is a need for viable whole blood processing techniques for rapid and reliable tumor cell detection that do not require tagging. Micropore biosensors have previously been used to differentiate tumor cells from normal cells and we have used a micropore-based electromechanical transducer to differentiate one type of tumor cells from the other types. This device generated electrical signals that were characteristic of the cell properties. Three non-small cell lung cancer (NSCLC) cell lines, NCl-H1155, A549 and NCI-H460, were successfully differentiated. NCI-H1155, due to their comparatively smaller size, were found to be the quickest in translocating through the micropore. Their translocation through a 15 μm micropore caused electrical pulses with an average translocation time of 101 ± 9.4 μs and an average peak amplitude of 3.71 ± 0.42 μA, whereas translocation of A549 and NCI-H460 caused pulses with average translocation times of 126 ± 17.9 μs and 148 ± 13.7 μs and average peak amplitudes of 4.58 ± 0.61 μA and 5.27 ± 0.66 μA, respectively. This transformation of the differences in cell properties into differences in the electrical profiles (i.e. the differences in peak amplitudes and translocation times) with this electromechanical transducer is a quantitative way to differentiate these lung cancer cells. The solid-state micropore device processed whole biological samples without any pre-processing requirements and is thus ideal for point-of-care applications.

  1. Palmprint Recognition across Different Devices

    PubMed Central

    Jia, Wei; Hu, Rong-Xiang; Gui, Jie; Zhao, Yang; Ren, Xiao-Ming

    2012-01-01

    In this paper, the problem of Palmprint Recognition Across Different Devices (PRADD) is investigated, which has not been well studied so far. Since there is no publicly available PRADD image database, we created a non-contact PRADD image database containing 12,000 grayscale captured from 100 subjects using three devices, i.e., one digital camera and two smart-phones. Due to the non-contact image acquisition used, rotation and scale changes between different images captured from a same palm are inevitable. We propose a robust method to calculate the palm width, which can be effectively used for scale normalization of palmprints. On this PRADD image database, we evaluate the recognition performance of three different methods, i.e., subspace learning method, correlation method, and orientation coding based method, respectively. Experiments results show that orientation coding based methods achieved promising recognition performance for PRADD. PMID:22969380

  2. Determination of effective mechanical properties of a double-layer beam by means of a nano-electromechanical transducer

    SciTech Connect

    Hocke, Fredrik; Pernpeintner, Matthias; Gross, Rudolf; Zhou, Xiaoqing; Kippenberg, Tobias J.; Schliesser, Albert; Huebl, Hans

    2014-09-29

    We investigate the mechanical properties of a doubly clamped, double-layer nanobeam embedded into an electromechanical system. The nanobeam consists of a highly pre-stressed silicon nitride and a superconducting niobium layer. By measuring the mechanical displacement spectral density both in the linear and the nonlinear Duffing regime, we determine the pre-stress and the effective Young's modulus of the nanobeam. An analytical double-layer model quantitatively corroborates the measured values. This suggests that this model can be used to design mechanical multilayer systems for electro- and optomechanical devices, including materials controllable by external parameters such as piezoelectric, magnetostrictive, or in more general multiferroic materials.

  3. Determination of effective mechanical properties of a double-layer beam by means of a nano-electromechanical transducer

    NASA Astrophysics Data System (ADS)

    Hocke, Fredrik; Pernpeintner, Matthias; Zhou, Xiaoqing; Schliesser, Albert; Kippenberg, Tobias J.; Huebl, Hans; Gross, Rudolf

    2014-09-01

    We investigate the mechanical properties of a doubly clamped, double-layer nanobeam embedded into an electromechanical system. The nanobeam consists of a highly pre-stressed silicon nitride and a superconducting niobium layer. By measuring the mechanical displacement spectral density both in the linear and the nonlinear Duffing regime, we determine the pre-stress and the effective Young's modulus of the nanobeam. An analytical double-layer model quantitatively corroborates the measured values. This suggests that this model can be used to design mechanical multilayer systems for electro- and optomechanical devices, including materials controllable by external parameters such as piezoelectric, magnetostrictive, or in more general multiferroic materials.

  4. Kirchhoff plate theory-based electromechanically-coupled analytical model considering inertia and stiffness effects of a surface-bonded piezoelectric patch

    NASA Astrophysics Data System (ADS)

    Yoon, Heonjun; Youn, Byeng D.; Kim, Heung Soo

    2016-02-01

    As a compact and durable design concept, piezoelectric energy harvesting skin (PEH skin) has been recently proposed for self-powered electronic device applications. This study aims to develop an electromechanically-coupled analytical model of PEH skin considering the inertia and stiffness effects of a piezoelectric patch. Based on Kirchhoff plate theory, Hamilton’s principle is used to derive the electromechanically-coupled differential equation of motion. Due to the geometric discontinuity of the piezoelectric patch, the Rayleigh-Ritz method is applied to calculate the natural frequency and corresponding mode shapes. The electrical circuit equation is derived from Gauss’s law. Output voltage is estimated by solving the equation of motion and electrical circuit equation, simultaneously. For the purpose of evaluating the predictive capability, the results of the electromechanically-coupled analytical model are compared with those of the finite element method in a hierarchical manner. The outstanding merits of the electromechanically-coupled analytical model of PEH skin are three-fold: (1) consideration of the inertia and stiffness effects of the piezoelectric patches; (2) physical parameterization between the two-dimensional mechanical configuration and piezoelectric transduction; (3) manipulability of the twisting modes of a cantilever plate with a small aspect ratio.

  5. A tunable carbon nanotube electromechanical oscillator

    NASA Astrophysics Data System (ADS)

    Sazonova, Vera; Yaish, Yuval; Üstünel, Hande; Roundy, David; Arias, Tomás A.; McEuen, Paul L.

    2004-09-01

    Nanoelectromechanical systems (NEMS) hold promise for a number of scientific and technological applications. In particular, NEMS oscillators have been proposed for use in ultrasensitive mass detection, radio-frequency signal processing, and as a model system for exploring quantum phenomena in macroscopic systems. Perhaps the ultimate material for these applications is a carbon nanotube. They are the stiffest material known, have low density, ultrasmall cross-sections and can be defect-free. Equally important, a nanotube can act as a transistor and thus may be able to sense its own motion. In spite of this great promise, a room-temperature, self-detecting nanotube oscillator has not been realized, although some progress has been made. Here we report the electrical actuation and detection of the guitar-string-like oscillation modes of doubly clamped nanotube oscillators. We show that the resonance frequency can be widely tuned and that the devices can be used to transduce very small forces.

  6. Non-contact large-scale separated surfaces flatness measurement by using laser beam and laser distance sensor

    NASA Astrophysics Data System (ADS)

    Li, Xudong; Fan, Bo; Jiang, Hongzhi; Zhao, Huijie

    2015-07-01

    Large-scale separated surface is very common in modern manufacturing industry. The measurement of the flatness of such surfaces is one of the most important procedures when evaluating the manufacturing quality. Usually, the measurement needs to be accomplished in an in-situ and non-contact way. Although there are many conventional approaches such as autocollimator, capacitance displacement sensor and even CMM, they can not meet the needs from the separated surfaces measurement either because of their contact-nature or inapplicable to separated surfaces. A non-contact large-scale separated surfaces flatness measurement device utilizing laser beam and laser distance sensor (LDS) is proposed. The laser beam is rotated to form an optical reference plane. The LDS is used to measure the distance between the surface and the sensor accurately. A Position Sensitive Detector (PSD) is mounted with the LDS firmly to determine the distance between the LDS and the reference plane and then the distance between the surface and the reference plane can be obtained by subtracting the two distances. The device can be easily mounted on a machine-tool spindle and is moved to measure all the separated surfaces. Then all the data collected are used to evaluate the flatness of these separated surfaces. The accuracy analysis, the corresponding flatness evaluation algorithm, the prototype construction and experiments are also discussed. The proposed approach and device feature as high accuracy, in-situ usage and the higher degree of automatic measurement, and can be used in the areas that call for non-contact and separated surfaces measurement.

  7. Ionically-mediated electromechanical hysteresis in transition metal oxides.

    PubMed

    Kim, Yunseok; Morozovska, Anna N; Kumar, Amit; Jesse, Stephen; Eliseev, Eugene A; Alibart, Fabien; Strukov, Dmitri; Kalinin, Sergei V

    2012-08-28

    Nanoscale electromechanical activity, remanent polarization states, and hysteresis loops in paraelectric TiO(2) and SrTiO(3) thin films are observed using scanning probe microscopy. The coupling between the ionic dynamics and incipient ferroelectricity in these materials is analyzed using extended Landau-Ginzburg-Devonshire (LGD) theory. The possible origins of electromechanical coupling including ionic dynamics, surface-charge induced electrostriction, and ionically induced ferroelectricity are identified. For the latter, the ionic contribution can change the sign of first order LGD expansion coefficient, rendering material effectively ferroelectric. The lifetime of these ionically induced ferroelectric states is then controlled by the transport time of the mobile ionic species and well above that of polarization switching. These studies provide possible explanation for ferroelectric-like behavior in centrosymmetric transition metal oxides.

  8. Controller modeling and evaluation for PCV electro-mechanical actuator

    NASA Astrophysics Data System (ADS)

    Parker, Joey K.

    1993-11-01

    Hydraulic actuators are currently used to operate the propellant control valves (PCV) for the space shuttle main engine (SSME) and other rocket engines. These actuators are characterized by large power to weight ratios, large force capabilities, and rapid accelerations, which favor their use in control valve applications. However, hydraulic systems are also characterized by susceptibility to contamination, which leads to frequent maintenance requirements. The Control Mechanisms Branch (EP34) of the Component Development Division of the Propulsion Laboratory at the Marshall Space Flight Center (MSFC) has been investigating the application of electromechanical actuators as replacements for the hydraulic units in PCV's over the last few years. This report deals with some testing and analysis of a PCV electromechanical actuator (EMA) designed and fabricated by HR Textron, Inc. This prototype actuator has undergone extensive testing by EP34 personnel since early 1993. At this time, the performance of the HR Textron PCV EMA does not meet requirements for position tracking.

  9. Controller modeling and evaluation for PCV electro-mechanical actuator

    NASA Technical Reports Server (NTRS)

    Parker, Joey K.

    1993-01-01

    Hydraulic actuators are currently used to operate the propellant control valves (PCV) for the space shuttle main engine (SSME) and other rocket engines. These actuators are characterized by large power to weight ratios, large force capabilities, and rapid accelerations, which favor their use in control valve applications. However, hydraulic systems are also characterized by susceptibility to contamination, which leads to frequent maintenance requirements. The Control Mechanisms Branch (EP34) of the Component Development Division of the Propulsion Laboratory at the Marshall Space Flight Center (MSFC) has been investigating the application of electromechanical actuators as replacements for the hydraulic units in PCV's over the last few years. This report deals with some testing and analysis of a PCV electromechanical actuator (EMA) designed and fabricated by HR Textron, Inc. This prototype actuator has undergone extensive testing by EP34 personnel since early 1993. At this time, the performance of the HR Textron PCV EMA does not meet requirements for position tracking.

  10. A Bio-Inspired Electromechanical System: Artificial Hair Cell

    NASA Astrophysics Data System (ADS)

    Ahn, Kang-Hun

    Inspired by recent biophysical study on the auditory sensory organs, we study electromechanical system which functions similar to the hair cell of the ear. One of the important mechanisms of hair cells, adaptation, is mimicked by an electromechanical feedback loop. The proposed artificial hair cell functions similar to a living sensory organ in the sense that it senses input force signal in spite of the relatively strong noise. Numerical simulation of the proposed system shows otoacoustic sound emission, which was observed in the experiments on the hair cells of the bullfrog. This spontaneous motion is noise-induced periodic motion which is controlled by the time scale of adaptation process and the mechanical damping.

  11. Decreasing Outer Hair Cell Membrane Cholesterol Increases Cochlear Electromechanics

    NASA Astrophysics Data System (ADS)

    Brownell, William E.; Jacob, Stefan; Hakizimana, Pierre; Ulfendahl, Mats; Fridberger, Anders

    2011-11-01

    The effect of decreasing membrane cholesterol on the mechanical response of the cochlea to acoustic and/or electrical stimulation was monitored using laser interferometry. In contrast to pharmacological interventions that typically decrease cochlear electromechanics, reducing membrane cholesterol increased the response. The electromechanical response in untreated preparations was asymmetric with greater displacements in response to positive currents and cholesterol depletion increased the asymmetry. The results confirm that outer hair cell electromotility is enhanced by low membrane cholesterol. The asymmetry of the response indicates the outer hair cell resting membrane potential is hyperpolarized relative to the voltage of maximum gain for the outer hair cell voltage-displacement function. The magnitude of the response increase suggests a non-uniform distribution of cholesterol along the lateral wall of normal adult outer hair cells.

  12. Ab-initio modeling of electromechanical coupling at Si surfaces

    SciTech Connect

    Hoppe, Sandra; Müller, Stefan; Michl, Anja; Weissmüller, Jörg

    2014-08-21

    The electromechanical coupling at the silicon (100) and (111) surfaces was studied via density functional theory by calculating the response of the ionization potential and the electron affinity to different types of strain. We find a branched strain response of those two quantities with different coupling coefficients for negative and positive strain values. This can be attributed to the reduced crystal symmetry due to anisotropic strain, which partially lifts the degeneracy of the valence and conduction bands. Only the Si(111) electron affinity exhibits a monotonously linear strain response, as the conduction band valleys remain degenerate under strain. The strain response of the surface dipole is linear and seems to be dominated by volume changes. Our results may help to understand the mechanisms behind electromechanical coupling at an atomic level in greater detail and for different electronic and atomic structures.

  13. A review of mechanical and electromechanical properties of piezoelectric nanowires.

    PubMed

    Espinosa, Horacio D; Bernal, Rodrigo A; Minary-Jolandan, Majid

    2012-09-01

    Piezoelectric nanowires are promising building blocks in nanoelectronic, sensing, actuation and nanogenerator systems. In spite of great progress in synthesis methods, quantitative mechanical and electromechanical characterization of these nanostructures is still limited. In this article, the state-of-the art in experimental and computational studies of mechanical and electromechanical properties of piezoelectric nanowires is reviewed with an emphasis on size effects. The review covers existing characterization and analysis methods and summarizes data reported in the literature. It also provides an assessment of research needs and opportunities. Throughout the discussion, the importance of coupling experimental and computational studies is highlighted. This is crucial for obtaining unambiguous size effects of nanowire properties, which truly reflect the effect of scaling rather than a particular synthesis route. We show that such a combined approach is critical to establish synthesis-structure-property relations that will pave the way for optimal usage of piezoelectric nanowires. PMID:22581695

  14. Non-contact current and voltage sensor

    SciTech Connect

    Carpenter, Gary D; El-Essawy, Wael; Ferreira, Alexandre Peixoto; Keller, Thomas Walter; Rubio, Juan C; Schappert, Michael A

    2014-03-25

    A detachable current and voltage sensor provides an isolated and convenient device to measure current passing through a conductor such as an AC branch circuit wire, as well as providing an indication of an electrostatic potential on the wire, which can be used to indicate the phase of the voltage on the wire, and optionally a magnitude of the voltage. The device includes a housing that contains the current and voltage sensors, which may be a ferrite cylinder with a hall effect sensor disposed in a gap along the circumference to measure current, or alternative a winding provided through the cylinder along its axis and a capacitive plate or wire disposed adjacent to, or within, the ferrite cylinder to provide the indication of the voltage.

  15. Non-contact direct measurement of the magnetocaloric effect in thin samples

    SciTech Connect

    Cugini, F. Porcari, G.; Solzi, M.

    2014-07-15

    An experimental setup, based on a non-contact temperature sensor, is proposed to directly measure the magnetocaloric effect of samples few micrometers thick. The measurement of the adiabatic temperature change of foils and ribbons is fundamental to design innovative devices based on magnetocaloric thin materials or micro-structuring bulk samples. The reliability of the proposed setup is demonstrated by comparing the measurements performed on a bulk gadolinium sample with the results obtained by an experimental setup based on a Cernox bare chip thermoresistance and by in-field differential scanning calorimetry. We show that this technique can measure the adiabatic temperature variation on gadolinium sheets as thin as 27 μm. Heat transfer simulations are added to describe the capability of the presented technique.

  16. Non-contact direct measurement of the magnetocaloric effect in thin samples.

    PubMed

    Cugini, F; Porcari, G; Solzi, M

    2014-07-01

    An experimental setup, based on a non-contact temperature sensor, is proposed to directly measure the magnetocaloric effect of samples few micrometers thick. The measurement of the adiabatic temperature change of foils and ribbons is fundamental to design innovative devices based on magnetocaloric thin materials or micro-structuring bulk samples. The reliability of the proposed setup is demonstrated by comparing the measurements performed on a bulk gadolinium sample with the results obtained by an experimental setup based on a Cernox bare chip thermoresistance and by in-field differential scanning calorimetry. We show that this technique can measure the adiabatic temperature variation on gadolinium sheets as thin as 27 μm. Heat transfer simulations are added to describe the capability of the presented technique. PMID:25085161

  17. The non-contact precision measurement and noise reduction method for liquid volume metrology

    NASA Astrophysics Data System (ADS)

    Wang, Jintao; Liu, Ziyong; Tong, Lin; Zhang, Long; Guo, Ligong; Bao, Xuesong

    2011-12-01

    Liquid volume is one important metrology method for commercial transaction in international trade, and vertical tank is used as main metrology tool. One non-contact optical measurement system was raised by using laser scanning method. The coordinates of vertical tank shell were acquired by phase-shift ranging method and angular measurement, and the set of coordinates is named as data cloud. The measurement errors of distance and angle are 2mm and 2" respectively. Wavelet was applied to noise reduction and curve feature extraction for data cloud. Iterative method was used to deduce the radius at each course height. One 1000m3 vertical tank used as test object, comparison experiment was carried out with strap method (international arbitral standard). The experimental results show that the noise due to tank shell surface characteristics and laser scanning devices could be filtered satisfactorily, and the local curve features of tank shell were described correctly.

  18. A nonlinear model for the layer between plates in acoustic noncontact transportation

    NASA Astrophysics Data System (ADS)

    Li, Jin; Cao, Wenwu; Zhang, Wenjun

    2014-12-01

    To more accurately describe the noncontact transport behavior of traveling acoustic waves, a nonlinear model is presented in this paper for the squeeze gas film with consideration of gas inertia in the case of a large amplitude motion and low viscosity of the gas. A closed form solution is derived for the vertical and horizontal forces of the film from this model. Our results have shown that the gas inertia has a significant influence on the pressure distribution in the squeeze film, and the inertial force is higher than the viscous force. The predicted levitation and horizontal driving forces are found to be in good agreement with our experimental measurements. Our inertia model provides a powerful tool for the force estimation and its potential benefits could be far reaching. The accurate prediction of these forces is useful to design the system for levitating and transporting planar objects, such as MEMS devices, glass substrates, and IC chips

  19. Electromechanical tuning of vertically-coupled photonic crystal nanobeams.

    PubMed

    Midolo, L; Yoon, S N; Pagliano, F; Xia, T; van Otten, F W M; Lermer, M; Höfling, S; Fiore, A

    2012-08-13

    We present the design, the fabrication and the characterization of a tunable one-dimensional (1D) photonic crystal cavity (PCC) etched on two vertically-coupled GaAs nanobeams. A novel fabrication method which prevents their adhesion under capillary forces is introduced. We discuss a design to increase the flexibility of the structure and we demonstrate a large reversible and controllable electromechanical wavelength tuning (> 15 nm) of the cavity modes. PMID:23038566

  20. Effect of nonlinear electromechanical interaction upon wind power generator behavior

    NASA Astrophysics Data System (ADS)

    Selyutskiy, Yury D.; Klimina, Liubov A.

    2014-12-01

    A mathematical model is developed for describing a small horizontal axis wind turbine with electric generator, such that the electromechanical interaction is non-linear in current. Dependence of steady regimes of the system upon parameters of the model is studied. In particular, it is shown that increase of wind speed causes qualitative restructuring of the set of steady regimes, which leads to considerable change in behavior of the wind power generator. The proposed model is verified against data obtained in experiments.

  1. Electromechanical actuator for the tongs of a servomanipulator

    DOEpatents

    Martin, H. Lee; Killough, Stephen M.

    1986-01-01

    Computer-augmented electromechanical system is provided for controlling the tongs of a servomanipulator. The mechanical tongs are motor-driven through the remote slave arm of the manipulator, and the motor control current is supplied by a position sensor which senses the position of a spring-loaded trigger in the master arm handle on the manipulator. The actuator for the tongs provides the operator with artificial force reflection in a unilateral force-force control loop.

  2. Nano-hierarchical structure and electromechanical coupling properties of clamshell.

    PubMed

    Li, Tao; Zeng, Kaiyang

    2012-10-01

    Electromechanical coupling is a nearly universal property of biomaterials, and may play an important role in many physiological and functional phenomena. The intrinsic or externally-generated electric field within biomaterials may also contribute to their predominant mechanical properties. Mollusc shells are well known for their outstanding mechanical properties, which are generally believed to originate from their hierarchical structures in multi-levels. This paper is therefore focused on the studies of the hierarchical structures and electromechanical coupling behaviors of clamshell from micro- to nano-levels, and in particular, the biopolymer concentrated regions. Detailed studies are performed to characterize the piezoelectric and ferroelectric properties of clamshell. It was found that the piezoresponse of clamshell is originated from the biopolymers between the mineral grains, as well as those intercalated within the mineral crystalline structure after the biomineralization process. Local ferroelectric hysteresis loops of clamshell have also been observed and analyzed on the samples with different orientations, biopolymer contents, or moisture contents. It is believed that the overall functioning of the clamshell or even other mollusc shells may incorporate many mechanisms interacting together, rather than originate from the hierarchical structure alone. This study of the electromechanical coupling effects of clamshell can be a path to have more comprehensive understandings of the properties and behaviors of mollusc shells.

  3. Electromechanical decoupled model for cantilever-beam piezoelectric energy harvesters

    NASA Astrophysics Data System (ADS)

    Tan, T.; Yan, Z.; Hajj, M.

    2016-09-01

    Analysis of cantilever-based piezoelectric energy harvesting systems is usually performed using coupled equations that represent the mechanical displacement and the voltage output. These equations are then solved simultaneously. In contrast to this representation, we use analytical solutions of the governing equation to derive an algebraic equation of the power as a function of the beam displacement, electromechanical coefficients, and the load resistance. Such an equation can be more useful in the design of such harvesters. Particularly, the mechanical displacement is computed from a mechanical governing equation with modified natural frequency and damping ratio that account for the electromechanical coupling. The voltage and the harvested power are then obtained by relating them directly to the mechanical displacement. We validate the proposed analysis by comparing its solution including the tip displacement and harvested power with those of numerical simulations of the governing equations. To demonstrate the generality of the proposed approach, we consider the cases of base excitation, galloping, and autoparametric vibration. The model proposed in this study simplifies the electromechanical coupling problem for practical applications of cantilever-beam piezoelectric energy harvesting systems.

  4. Theory of electromechanical resonance in magnetostrictive - piezoelectric multilayer composites

    NASA Astrophysics Data System (ADS)

    Filippov, D. A.; Nan, C. W.; Srinivasan, G.

    2005-03-01

    The theory of electromechanical resonance in multilayer magnetostrictive - piezoelectric composites is developed. The theory is based on the use of initial (not effective) parameters of magnetostrictive and piezoelectric phases. Equations of motion were used to obtain an expression for the frequency-dependence of magnetoelectric response in a multilayer composite [1,2]. The enhanced magnetoelectric response at the electromechanical resonance is dependent on the interface coupling. The calculations predict a peak in the magnetoelectric voltage coefficient at electromechanical resonance, with a two-order of magnitude increase relative to low-frequency values. These predictions are in agreement with data for ferrite-lead zirconante titanate (PZT) bilayers and metal-PZT-metal trilayers. 1. M. I. Bichurin, D.A. Filippov, V. M. Petrov, V. M. Laletin, N. Paddubnaya, and G. Srinivasan, Phys. Rev., B 68, 132408 (2003). 2. D. A. Fillipov, M. I. Bichurin, V. M. Petrov, V. M. Laletsin, N. N. Puddubnaya, and G. Srinivasan, Magnetoelectric Interaction Phenomena in Crystals-NATO Science Series II. Vol. 164, Eds. M. Fiebig, V. V. Eremenko, and I. E. Chupis (Kluwer Academic Publishers, London, 2004), p.71-80. - supported by grants from the Russian Ministry of Education (Å02-3.4-278), the Universities of Russia Foundation (UNR 01.01.026) and the National Science Foundation (DMR-0302254).

  5. Modeling of dielectric viscoelastomers with application to electromechanical instabilities

    NASA Astrophysics Data System (ADS)

    Wang, Shuolun; Decker, Martina; Henann, David L.; Chester, Shawn A.

    2016-10-01

    Soft dielectrics are electrically-insulating elastomeric materials, which are capable of large deformation and electrical polarization, and are used as smart transducers for converting between mechanical and electrical energy. While much theoretical and computational modeling effort has gone into describing the ideal, time-independent behavior of these materials, viscoelasticity is a crucial component of the observed mechanical response and hence has a significant effect on electromechanical actuation. In this paper, we report on a constitutive theory and numerical modeling capability for dielectric viscoelastomers, able to describe electromechanical coupling, large-deformations, large-stretch chain-locking, and a time-dependent mechanical response. Our approach is calibrated to the widely-used soft dielectric VHB 4910, and the finite-element implementation of the model is used to study the role of viscoelasticity in instabilities in soft dielectrics, namely (1) the pull-in instability, (2) electrocreasing, (3) electrocavitation, and (4) wrinkling of a pretensioned three-dimensional diaphragm actuator. Our results show that viscoelastic effects delay the onset of instability under monotonic electrical loading and can even suppress instabilities under cyclic loading. Furthermore, quantitative agreement is obtained between experimentally measured and numerically simulated instability thresholds. Our finite-element implementation will be useful as a modeling platform for further study of electromechanical instabilities and for harnessing them in design and is provided as online supplemental material to aid other researchers in the field.

  6. Micro electromechanical systems (MEMS) for mechanical engineers

    SciTech Connect

    Lee, A. P., LLNL

    1996-11-18

    The ongoing advances in Microelectromechanical Systems (MEMS) are providing man-kind the freedom to travel to dimensional spaces never before conceivable. Advances include new fabrication processes, new materials, tailored modeling tools, new fabrication machines, systems integration, and more detailed studies of physics and surface chemistry as applied to the micro scale. In the ten years since its inauguration, MEMS technology is penetrating industries of automobile, healthcare, biotechnology, sports/entertainment, measurement systems, data storage, photonics/optics, computer, aerospace, precision instruments/robotics, and environment monitoring. It is projected that by the turn of the century, MEMS will impact every individual in the industrial world, totaling sales up to $14 billion (source: System Planning Corp.). MEMS programs in major universities have spawned up all over the United States, preparing the brain-power and expertise for the next wave of MEMS breakthroughs. It should be pointed out that although MEMS has been initiated by electrical engineering researchers through the involvement of IC fabrication techniques, today it has evolved such that it requires a totally multi-disciplinary team to develop useful devices. Mechanical engineers are especially crucial to the success of MEMS development, since 90% of the physical realm involved is mechanical. Mechanical engineers are needed for the design of MEMS, the analysis of the mechanical system, the design of testing apparatus, the implementation of analytical tools, and the packaging process. Every single aspect of mechanical engineering is being utilized in the MEMS field today, however, the impact could be more substantial if more mechanical engineers are involved in the systems level designing. In this paper, an attempt is made to create the pathways for a mechanical engineer to enter in the MEMS field. Examples of application in optics and medical devices will be used to illustrate how mechanical

  7. System and method for interfacing large-area electronics with integrated circuit devices

    DOEpatents

    Verma, Naveen; Glisic, Branko; Sturm, James; Wagner, Sigurd

    2016-07-12

    A system and method for interfacing large-area electronics with integrated circuit devices is provided. The system may be implemented in an electronic device including a large area electronic (LAE) device disposed on a substrate. An integrated circuit IC is disposed on the substrate. A non-contact interface is disposed on the substrate and coupled between the LAE device and the IC. The non-contact interface is configured to provide at least one of a data acquisition path or control path between the LAE device and the IC.

  8. Thermo-electromechanical Behavior of Piezoelectric Nanofibers.

    PubMed

    Baniasadi, Mahmoud; Xu, Zhe; Hong, Seokjin; Naraghi, Mohammad; Minary-Jolandan, Majid

    2016-02-01

    High performance piezoelectric devices based on arrays of PVDF-TrFE nanofibers have been introduced in the literature for a variety of applications including energy harvesting and sensing. In this Research Article, we utilize uniaxial tensile test on arrays of nanofibers, microtensile, and nanoindentation and piezo-response force microscopy (PFM) on individual nanofibers, as wells as DSC, XRD, and FTIR spectroscopy to investigate the effect of annealing on microstructure, mechanical, and piezoelectric properties of arrays and individual electrospun nanofibers. For PVDF-TrFE nanofibers annealing in a temperature between the Curie and melting temperature (in paraelectric phase) results in ∼70% increase in crystallinity of the nanofibers. The findings of our multiscale experiments reveal that this improvement in crystallinity results in ∼3-fold increase in elastic modulus, and ∼55% improvement in piezoelectric constant. Meanwhile, the ductility and tensile toughness of the nanofibers drop by ∼1 order of magnitude. In addition, nanoscale cracks were observed on the surface of the annealed nanofibers; however, they did not result in significant change in the strength of the nanofibers. The results of this work may have important implications for applications of PVDF-TrFE in energy harvesting, biomedical, and sensor areas.

  9. Anatomical co-registration using spatio-temporal features of a non-contact near-infrared optical scanner

    NASA Astrophysics Data System (ADS)

    Jung, Young-Jin; Gonzalez, Jean; Rodriguez, Suset; Velez Mejia, Maximiliano; Clark, Gabrielle; Godavarty, Anuradha

    2014-02-01

    Non-contact based near-infrared (NIR) optical imaging devices are developed for non-invasive imaging of deep tissues in various clinical applications. Most of these devices focus on obtaining the spatial information for anatomical co-registration of blood vessels as in sub-surface vein localization applications. In the current study, the anatomical co-registration of blood vessels based on spatio-temporal features was performed using NIR optical imaging without the use of external contrast agents. A 710 nm LED source and a compact CCD camera system were employed during simple cuff (0 to 60 mmHg) experiment in order to acquire the dynamic NIR data from the dorsum of a hand. The spatio-temporal features of dynamic NIR data were extracted from the cuff experimental study to localize vessel according to blood dynamics. The blood vessels shape is currently reconstructed from the dynamic data based on spatio-temporal features. Demonstrating the spatio-temporal feature of blood dynamic imaging using a portable non-contact NIR imaging device without external contrast agents is significant for applications such as peripheral vascular diseases.

  10. Double-Layer Mediated Electromechanical Response of Amyloid Fibrils in Liquid Environment

    SciTech Connect

    Nikiforov, Maxim; Thompson, G. L.; Reukov, Vladimir V; Jesse, Stephen; Guo, Senli; Rodriguez, Brian; Seal, Katyayani; Vertegel, Alexey; Kalinin, Sergei V

    2010-01-01

    Harnessing electrical bias-induced mechanical motion on the nanometer and molecular scale is a critical step toward understanding the fundamental mechanisms of redox processes and implementation of molecular electromechanical machines. Probing these phenomena in biomolecular systems requires electromechanical measurements be performed in liquid environments. Here we demonstrate the use of band excitation piezoresponse force microscopy for probing electromechanical coupling in amyloid fibrils. The approaches for separating the elastic and electromechanical contributions based on functional fits and multivariate statistical analysis are presented. We demonstrate that in the bulk of the fibril the electromechanical response is dominated by double-layer effects (consistent with shear piezoelectricity of biomolecules), while a number of electromechanically active hot spots possibly related to structural defects are observed.

  11. Sequence-specific DNA detection at 10 fM by electromechanical signal transduction.

    PubMed

    Esfandiari, Leyla; Lorenzini, Michael; Kocharyan, Gayane; Monbouquette, Harold G; Schmidt, Jacob J

    2014-10-01

    Target DNA fragments at 10 fM concentration (approximately 6 × 10(5) molecules) were detected against a DNA background simulating the noncomplementary genomic DNA present in real samples using a simple, PCR-free, optics-free approach based on electromechanical signal transduction. The development of a rapid, sensitive, and cost-effective nucleic acid detection platform is highly desired for a range of diverse applications. We previously described a potentially low-cost device for sequence-specific nucleic acid detection based on conductance change measurement of a pore blocked by electrophoretically mobilized bead-(peptide nucleic acid probe) conjugates upon hybridization with target nucleic acid. Here, we demonstrate the operation of our device with longer DNA targets, and we describe the resulting improvement in the limit of detection (LOD). We investigated the detection of DNA oligomers of 110, 235, 419, and 1613 nucleotides at 1 pM to 1 fM and found that the LOD decreased as DNA length increased, with 419 and 1613 nucleotide oligomers detectable down to 10 fM. In addition, no false positive responses were obtained with noncomplementary, control DNA fragments of similar length. The 1613-base DNA oligomer is similar in size to 16S rRNA, which suggests that our device may be useful for detection of pathogenic bacteria at clinically relevant concentrations based on recognition of species-specific 16S rRNA sequences.

  12. A High-order Eulerian-Lagrangian Finite Element Method for Coupled Electro-mechanical Systems

    NASA Astrophysics Data System (ADS)

    Brandstetter, Gerd

    The main focus of this work is on the development of a high-order Eulerian-Lagrangian finite element method for the simulation of electro-mechanical systems. The coupled problem is solved by a staggered scheme, where the mechanical motion is discretized by standard Lagrangian finite elements, and the electrical field is solved on a fixed Eulerian grid with embedded boundary conditions. Traditional Lagrangian-Lagrangian or arbitrary Lagrangian-Eulerian (ALE) methods encounter deficiencies, for example, when dealing with mesh distortion due to large deformations, or topology changes due to contacting bodies. The presented Eulerian-Lagrangian approach addresses these issues in a natural way. Within this context we develop a high-order immersed boundary discontinuous-Galerkin (IB-DG) method, which is shown to be necessary for (i) the accurate representation of the electrical gradient along nonlinear boundary features such as singular corners, and (ii) to achieve full convergence during the iterative global solution. We develop an implicit scheme based on the mid-point rule, as well as an explicit scheme based on the centered-difference method, with the incorporation of energy conserving, frictionless contact algorithms for an elastic-to-rigid-surface contact. The performance of the proposed method is assessed for several benchmark tests: the electro-static force vector around a singular corner, the quasi-static pull-in of an electro-mechanically actuated switch, the excitation of a carbon nanotube at resonance, and the cyclic impact simulation of a micro-electro-mechanical resonant-switch. We report improved accuracy for the high-order method as compared to low-order methods, and linear convergence in the iterative solution of the staggered scheme. Additionally, we investigate a Newton-Krylov shooting scheme in order to directly find cyclic steady states of electro-mechanical devices excited at resonance-- as opposed to a naive time-stepping from zero initial

  13. Noncontact anterior cruciate ligament injuries: risk factors and prevention strategies.

    PubMed

    Griffin, L Y; Agel, J; Albohm, M J; Arendt, E A; Dick, R W; Garrett, W E; Garrick, J G; Hewett, T E; Huston, L; Ireland, M L; Johnson, R J; Kibler, W B; Lephart, S; Lewis, J L; Lindenfeld, T N; Mandelbaum, B R; Marchak, P; Teitz, C C; Wojtys, E M

    2000-01-01

    An estimated 80,000 anterior cruciate ligament (ACL) tears occur annually in the United States. The highest incidence is in individuals 15 to 25 years old who participate in pivoting sports. With an estimated cost for these injuries of almost a billion dollars per year, the ability to identify risk factors and develop prevention strategies has widespread health and fiscal importance. Seventy percent of ACL injuries occur in noncontact situations. The risk factors for non-contact ACL injuries fall into four distinct categories: environmental, anatomic, hormonal, and biomechanical. Early data on existing neuromuscular training programs suggest that enhancing body control may decrease ACL injuries in women. Further investigation is needed prior to instituting prevention programs related to the other risk factors.

  14. Non-contact intracellular binding of chloroplasts in vivo

    NASA Astrophysics Data System (ADS)

    Li, Yuchao; Xin, Hongbao; Liu, Xiaoshuai; Li, Baojun

    2015-06-01

    Non-contact intracellular binding and controllable manipulation of chloroplasts in vivo was demonstrated using an optical fiber probe. Launching a 980-nm laser beam into a fiber, which was placed about 3 μm above the surface of a living plant (Hydrilla verticillata) leaf, enabled stable binding of different numbers of chloroplasts, as well as their arrangement into one-dimensional chains and two-dimensional arrays inside the leaf without damaging the chloroplasts. Additionally, the formed chloroplast chains were controllably transported inside the living cells. The optical force exerted on the chloroplasts was calculated to explain the experimental results. This method provides a flexible method for studying intracellular organelle interaction with highly organized organelle-organelle contact in vivo in a non-contact manner.

  15. Non-contact intracellular binding of chloroplasts in vivo.

    PubMed

    Li, Yuchao; Xin, Hongbao; Liu, Xiaoshuai; Li, Baojun

    2015-06-04

    Non-contact intracellular binding and controllable manipulation of chloroplasts in vivo was demonstrated using an optical fiber probe. Launching a 980-nm laser beam into a fiber, which was placed about 3 μm above the surface of a living plant (Hydrilla verticillata) leaf, enabled stable binding of different numbers of chloroplasts, as well as their arrangement into one-dimensional chains and two-dimensional arrays inside the leaf without damaging the chloroplasts. Additionally, the formed chloroplast chains were controllably transported inside the living cells. The optical force exerted on the chloroplasts was calculated to explain the experimental results. This method provides a flexible method for studying intracellular organelle interaction with highly organized organelle-organelle contact in vivo in a non-contact manner.

  16. Non-contact rail flaw detection system: first field test

    NASA Astrophysics Data System (ADS)

    Rizzo, Piervincenzo; Coccia, Stefano; Lanza di Scalea, Francesco; Bartoli, Ivan; Fateh, Mahmood

    2007-04-01

    Researchers at UCSD, with the initial support of NSF and the current support of the Federal Railroad Administration (FRA), have been working on a flaw detection prototype for rails that uses non-contact ultrasonic probing and robust data processing algorithms to provide high speed and high reliability defect detection in these structures. Besides the obvious advantages of non-contact probing, the prototype uses ultrasonic guided waves able to detect and quantify transverse cracks in the rail head, notoriously the most dangerous of all rail track defects. This paper will report on the first field test which was conducted in Gettysburg, PA in March 2006 with the technical support of ENSCO, Inc. Good results were obtained for the detection of both surface-breaking and internal cracks ranging in size from 2% cross-sectional head area (H.A.) reduction to 80% H.A. reduction.

  17. Theory of noncontact friction for atom-surface interactions

    NASA Astrophysics Data System (ADS)

    Jentschura, U. D.; Janke, M.; DeKieviet, M.

    2016-08-01

    The noncontact (van der Waals) friction is an interesting physical effect, which has been the subject of controversial scientific discussion. The direct friction term due to the thermal fluctuations of the electromagnetic field leads to a friction force proportional to 1 /Z5 (where Z is the atom-wall distance). The backaction friction term takes into account the feedback of thermal fluctuations of the atomic dipole moment onto the motion of the atom and scales as 1 /Z8 . We investigate noncontact friction effects for the interactions of hydrogen, ground-state helium, and metastable helium atoms with α -quartz (SiO2), gold (Au), and calcium difluorite (CaF2). We find that the backaction term dominates over the direct term induced by the thermal electromagnetic fluctuations inside the material, over wide distance ranges. The friction coefficients obtained for gold are smaller than those for SiO2 and CaF2 by several orders of magnitude.

  18. Photonic non-contact estimation of blood lactate level.

    PubMed

    Abraham, Chen; Beiderman, Yevgeny; Ozana, Nisan; Tenner, Felix; Schmidt, Michael; Sanz, Martin; Garcia, Javier; Zalevsky, Zeev

    2015-10-01

    The ability to measure the blood lactate level in a non-invasive, non-contact manner is very appealing to the sports industry as well as the home care field. That is mainly because this substance level is an imperative parameter in the course of devolving a personal workout programs. Moreover, the blood lactate level is also a pivotal means in estimation of muscles' performance capability. In this manuscript we propose an optical non-contact approach to estimate the concentration level of this parameter. Firstly, we introduce the connection between the physiological muscle tremor and the lactate blood levels. Secondly, we suggest a photonic optical method to estimate the physiological tremor. Lastly, we present the results of tests conducted to establish proof of concept to this connection. PMID:26504661

  19. Non-contacting Hand Image Certification System Using Morphological Analysis

    NASA Astrophysics Data System (ADS)

    Moritani, Motoki; Saitoh, Fumihiko

    This paper proposes a non-contacting certification system by using morphological analysis of hand images to access security control. The non-contacting hand image certification system is more effective than contacting system where psychological resistance and conformability are required. The morphology is applied to get useful individual characteristic even if the pose of a hand is changed. First, a hand image is captured using the transmitted lighting. Next, the wrist area is removed from the hand area. The pattern spectrum that represents the form of the hand area is measured by the morphological analysis, and the spectrum is normalized to the invariant pattern to the scale change. Finally, the certification of an individual is performed by the neural network. The experimental results show that the sufficient accuracy to certificate individuals was obtained by the proposed system.

  20. Sensors for noncontact vibration diagnostics in rotating machinery

    NASA Astrophysics Data System (ADS)

    Procházka, Pavel

    2016-06-01

    The paper deals with electromagnetic sensors for noncontact vibration diagnostics in rotating machinery. The sensors were designed for operational measurements in turbomachinery by means of the tip-timing method. The main properties of eddy-current, Hall effect, induction and magnetoresistive sensors are described and compared. Possible arrangements of the experimental systems for static and dynamic calibration of the sensors are suggested and discussed.

  1. Noncontacting measurement technologies for space propulsion condition monitoring

    NASA Astrophysics Data System (ADS)

    Randall, M. R.; Barkhoudarian, S.; Collins, J. J.; Schwartzbart, A.

    1987-12-01

    This paper describes four noncontacting measurement technologies that can be used in a turbopump condition monitoring system. The isotope wear analyzer, fiberoptic deflectometer, brushless torque-meter, and fiberoptic pyrometer can be used to monitor component wear, bearing degradation, instantaneous shaft torque, and turbine blade cracking, respectively. A complete turbopump condition monitoring system including these four technologies could predict remaining component life, thus reducing engine operating costs and increasing reliability.

  2. Noncontacting measurement technologies for space propulsion condition monitoring

    NASA Technical Reports Server (NTRS)

    Randall, M. R.; Barkhoudarian, S.; Collins, J. J.; Schwartzbart, A.

    1987-01-01

    This paper describes four noncontacting measurement technologies that can be used in a turbopump condition monitoring system. The isotope wear analyzer, fiberoptic deflectometer, brushless torque-meter, and fiberoptic pyrometer can be used to monitor component wear, bearing degradation, instantaneous shaft torque, and turbine blade cracking, respectively. A complete turbopump condition monitoring system including these four technologies could predict remaining component life, thus reducing engine operating costs and increasing reliability.

  3. Non-contact fluid characterization in containers using ultrasonic waves

    DOEpatents

    Sinha, Dipen N.

    2012-05-15

    Apparatus and method for non-contact (stand-off) ultrasonic determination of certain characteristics of fluids in containers or pipes are described. A combination of swept frequency acoustic interferometry (SFAI), wide-bandwidth, air-coupled acoustic transducers, narrowband frequency data acquisition, and data conversion from the frequency domain to the time domain, if required, permits meaningful information to be extracted from such fluids.

  4. Inductive Non-Contact Position Sensor

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert; Garcia, Alyssa; Simmons, Stephen

    2010-01-01

    Optical hardware has been developed to measure the depth of defects in the Space Shuttle Orbiter's windows. In this hardware, a mirror is translated such that its position corresponds to the defect's depth, so the depth measurement problem is transferred to a mirror-position measurement problem. This is preferable because the mirror is internal to the optical system and thus accessible. Based on requirements supplied by the window inspectors, the depth of the defects needs to be measured over a range of 200 microns with a resolution of about 100 nm and an accuracy of about 400 nm. These same requirements then apply to measuring the position of the mirror, and in addition, since this is a scanning system, a response time of about 10 ms is needed. A market search was conducted and no sensor that met these requirements that also fit into the available housing volume (less than one cubic inch) was found, so a novel sensor configuration was constructed to meet the requirements. This new sensor generates a nearly linearly varying magnetic field over a small region of space, which can easily be sampled, resulting in a voltage proportional to position. Experiments were done with a range of inductor values, drive voltages, drive frequencies, and inductor shapes. A rough mathematical model was developed for the device that, in most aspects, describes how it operates and what electrical parameters should be chosen for best performance. The final configuration met all the requirements, yielding a small rugged sensor that was easy to use and had nanometer resolution over more than the 200-micron range required. The inductive position sensor is a compact device (potentially as small as 2 cubic centimeters), which offers nanometer-position resolution over a demonstrated range of nearly 1 mm. One of its advantages is the simplicity of its electrical design. Also, the sensor resolution is nearly uniform across its operational range, which is in contrast to eddy current and

  5. Noncontact tissue oxygenation measurement using near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Niwayama, Masatsugu; Murata, Hideaki; Shinohara, Shigenobu

    2006-07-01

    Here, we present a noncontact tissue oxygenation monitor that uses near-infrared spectroscopy (NIRS). We examined changes in sensitivity of tissue oxygenation measurement due to changes in the distance between the optical probe and the skin surface using a Monte Carlo simulation and in vivo tests. We also examined the effects of skin and fat layer thickness. Photon migration was analyzed in a model consisting of the skin, fat, and muscle layers. The relationship between measurement sensitivity and the probe-tissue distance was obtained from the results of the simulation and was used for correction of measurements. A noncontact tissue oximeter was used to perform the in vivo tests and measure oxygen consumption of the forearm muscle. The value of corrected oxygen consumption was 0.12±0.03ml/(100gmin), which is consistent with previously reported values obtained using contact NIRS measurement and magnetic resonance spectroscopy. Quantitative measurement of oxygenation using noncontact NIRS is potentially useful for novel applications such as quantification of inflammation.

  6. Measuring elastic constants using non-contact ultrasonic techniques

    NASA Astrophysics Data System (ADS)

    Edwards, R. S.; Perry, R.; Cleanthous, D.; Backhouse, D. J.; Moore, I. J.; Clough, A. R.; Stone, D. I.

    2012-05-01

    The use of ultrasound for measuring elastic constants and phase transitions is well established. Standard measurements use piezoelectric transducers requiring couplant and contact with the sample. Recently, non-destructive testing (NDT) has seen an increase in the use of non-contact ultrasonic techniques, for example electromagnetic acoustic transducers (EMATs) and laser ultrasound, due to their many benefits. For measurements of single crystals over a range of temperatures non-contact techniques could also bring many benefits. These techniques do not require couplant, and hence do not suffer from breaking of the bond between transducer and sample during thermal cycling, and will potentially lead to a simpler and more adaptable measurement system with lower risk of sample damage. We present recent work adapting EMAT advances from NDT to measurements of single crystals at cryogenic temperatures and illustrate this with measurements of magnetic phase transitions in Gd64Sc36 using both contact and non-contact transducers. We discuss the measurement techniques implemented to overcome noise problems, and a digital pulse-echo-overlap technique, using data analysis in the frequency domain to measure the velocity.

  7. Non-contact friction for ion-surface interactions

    NASA Astrophysics Data System (ADS)

    Jentschura, Ulrich D.; Lach, Grzegorz

    2015-05-01

    Non-contact friction forces are exerted on physical systems through dissipative processes, when the two systems are not in physical contact with each other, or, in quantum mechanical terms, when the overlap of their wave functions is negligible. Non-contact friction is mediated by the exchange of virtual quanta, with the additional requirement that the scattering process needs to have an inelastic component. For finite-temperature ion-surface interactions, the friction is essentially caused by Ohmic resistance due to the motion of the image charge moving in a dielectric material. A conceivable experiment is difficult because the friction force needs to be isolated from the interaction with the image charge, which significantly distorts the ion's flight path. We propose an experimental setup which is designed to minimize the influence of the image charge interaction though a compensation mechanism, and evaluate the energy loss due to non-contact friction for helium ions (He+) interacting with gold, vanadium, titanium and graphite surfaces. Interactions with the infinite series of mirror charges in the plates are summed in terms of the logarithmic derivatives of the Gamma function, and of the Hurwitz zeta function.

  8. Laser device

    DOEpatents

    Scott, Jill R.; Tremblay, Paul L.

    2004-11-23

    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  9. Laser device

    DOEpatents

    Scott, Jill R.; Tremblay, Paul L.

    2007-07-10

    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  10. Use of radars to monitor stream discharge by noncontact methods

    USGS Publications Warehouse

    Costa, J.E.; Cheng, R.T.; Haeni, F.P.; Melcher, N.; Spicer, K.R.; Hayes, E.; Plant, W.; Hayes, K.; Teague, C.; Barrick, D.

    2006-01-01

    Conventional measurements of river flows are costly, time-consuming, and frequently dangerous. This report evaluates the use of a continuous wave microwave radar, a monostatic UHF Doppler radar, a pulsed Doppler microwave radar, and a ground-penetrating radar to measure river flows continuously over long periods and without touching the water with any instruments. The experiments duplicate the flow records from conventional stream gauging stations on the San Joaquin River in California and the Cowlitz River in Washington. The purpose of the experiments was to directly measure the parameters necessary to compute flow: surface velocity (converted to mean velocity) and cross-sectional area, thereby avoiding the uncertainty, complexity, and cost of maintaining rating curves. River channel cross sections were measured by ground-penetrating radar suspended above the river. River surface water velocity was obtained by Bragg scattering of microwave and UHF Doppler radars, and the surface velocity data were converted to mean velocity on the basis of detailed velocity profiles measured by current meters and hydroacoustic instruments. Experiments using these radars to acquire a continuous record of flow were conducted for 4 weeks on the San Joaquin River and for 16 weeks on the Cowlitz River. At the San Joaquin River the radar noncontact measurements produced discharges more than 20% higher than the other independent measurements in the early part of the experiment. After the first 3 days, the noncontact radar discharge measurements were within 5% of the rating values. On the Cowlitz River at Castle Rock, correlation coefficients between the USGS stream gauging station rating curve discharge and discharge computed from three different Doppler radar systems and GPR data over the 16 week experiment were 0.883, 0.969, and 0.992. Noncontact radar results were within a few percent of discharge values obtained by gauging station, current meter, and hydroacoustic methods. Time

  11. Highly Enhanced Electromechanical Stability of Large-Area Graphene with Increased Interfacial Adhesion Energy by Electrothermal-Direct Transfer for Transparent Electrodes.

    PubMed

    Kim, Jangheon; Kim, Gi Gyu; Kim, Soohyun; Jung, Wonsuk

    2016-09-01

    Graphene, a two-dimensional sheet of carbon atoms in a hexagonal lattice structure, has been extensively investigated for research and industrial applications as a promising material with outstanding electrical, mechanical, and chemical properties. To fabricate graphene-based devices, graphene transfer to the target substrate with a clean and minimally defective surface is the first step. However, graphene transfer technologies require improvement in terms of uniform transfer with a clean, nonfolded and nontorn area, amount of defects, and electromechanical reliability of the transferred graphene. More specifically, uniform transfer of a large area is a key challenge when graphene is repetitively transferred onto pretransferred layers because the adhesion energy between graphene layers is too low to ensure uniform transfer, although uniform multilayers of graphene have exhibited enhanced electrical and optical properties. In this work, we developed a newly suggested electrothermal-direct (ETD) transfer method for large-area high quality monolayer graphene with less defects and an absence of folding or tearing of the area at the surface. This method delivers uniform multilayer transfer of graphene by repetitive monolayer transfer steps based on high adhesion energy between graphene layers and the target substrate. To investigate the highly enhanced electromechanical stability, we conducted mechanical elastic bending experiments and reliability tests in a highly humid environment. This ETD-transferred graphene is expected to replace commercial transparent electrodes with ETD graphene-based transparent electrodes and devices such as a touch panels with outstanding electromechanical stability. PMID:27564120

  12. Mechanism of Electromechanical Coupling in Voltage-Gated Potassium Channels

    PubMed Central

    Blunck, Rikard; Batulan, Zarah

    2012-01-01

    Voltage-gated ion channels play a central role in the generation of action potentials in the nervous system. They are selective for one type of ion – sodium, calcium, or potassium. Voltage-gated ion channels are composed of a central pore that allows ions to pass through the membrane and four peripheral voltage sensing domains that respond to changes in the membrane potential. Upon depolarization, voltage sensors in voltage-gated potassium channels (Kv) undergo conformational changes driven by positive charges in the S4 segment and aided by pairwise electrostatic interactions with the surrounding voltage sensor. Structure-function relations of Kv channels have been investigated in detail, and the resulting models on the movement of the voltage sensors now converge to a consensus; the S4 segment undergoes a combined movement of rotation, tilt, and vertical displacement in order to bring 3–4e+ each through the electric field focused in this region. Nevertheless, the mechanism by which the voltage sensor movement leads to pore opening, the electromechanical coupling, is still not fully understood. Thus, recently, electromechanical coupling in different Kv channels has been investigated with a multitude of techniques including electrophysiology, 3D crystal structures, fluorescence spectroscopy, and molecular dynamics simulations. Evidently, the S4–S5 linker, the covalent link between the voltage sensor and pore, plays a crucial role. The linker transfers the energy from the voltage sensor movement to the pore domain via an interaction with the S6 C-termini, which are pulled open during gating. In addition, other contact regions have been proposed. This review aims to provide (i) an in-depth comparison of the molecular mechanisms of electromechanical coupling in different Kv channels; (ii) insight as to how the voltage sensor and pore domain influence one another; and (iii) theoretical predictions on the movement of the cytosolic face of the Kv channels during

  13. Micro Electro-Mechanical System (MEMS) Pressure Sensor for Footwear

    DOEpatents

    Kholwadwala, Deepesh K.; Rohrer, Brandon R.; Spletzer, Barry L.; Galambos, Paul C.; Wheeler, Jason W.; Hobart, Clinton G.; Givler, Richard C.

    2008-09-23

    Footwear comprises a sole and a plurality of sealed cavities contained within the sole. The sealed cavities can be incorporated as deformable containers within an elastic medium, comprising the sole. A plurality of micro electro-mechanical system (MEMS) pressure sensors are respectively contained within the sealed cavity plurality, and can be adapted to measure static and dynamic pressure within each of the sealed cavities. The pressure measurements can provide information relating to the contact pressure distribution between the sole of the footwear and the wearer's environment.

  14. Electromechanical characterization of silver-clad BSCCO tapes.

    SciTech Connect

    Salib, S.; Iyer, A. N.; Vipulanandan, C.; Salama, K.; Balachandran, U.; Energy Technology; Univ. of Houston

    1998-01-01

    During the fabrication of silver-clad BSCCO tapes they are subjected to stresses which could lead to degradation in their current transport property. In the present investigation, studies were made to evaluate the electromechanical characteristics of silver-clad BSCCO conductors. The tensile strain tolerance characteristics of the monofilament, multifilament and composite (15 and 30% of Ag powder by volume) tapes were evaluated at 77 K. The average irreversible strain of monofilament and composite tapes were 0.19 and 0.47%, respectively. No noticeable improvement in strain tolerance was observed with the multifilament tapes. Detailed phase and microstructural analysis have been conducted using scanning electron microscopy.

  15. Hopf and period-doubling bifurcations in an electromechanical resonator

    NASA Astrophysics Data System (ADS)

    Mahboob, I.; Dupuy, R.; Nishiguchi, K.; Fujiwara, A.; Yamaguchi, H.

    2016-08-01

    An electromechanical resonator is developed in which the dissipation can be dynamically eliminated. The resultant motional dynamics captured by the Van der Pol equation of motion opens up the possibility of a Hopf bifurcation where the mechanical resonance loses stability when the dissipation is eliminated and period-doubling bifurcations when the dissipation becomes negative. In this latter regime, the mechanical spectral response is characterised by multi-stability spanning a bandwidth that is more than an order of magnitude wider than the intrinsic linewidth and it sustains a peak structure that can be tuned by the input used to dynamically manipulate the dissipation.

  16. Design of high power electromechanical actuator for thrust vector control

    NASA Technical Reports Server (NTRS)

    Cowan, J. R.; Myers, W. N.

    1991-01-01

    NASA-Marshall has undertaken the development of electromechanical actuators (EMAs) for thrust vector control (TVC) augmentation system implementation. The TVC EMA presented has as its major components two three-phase brushless dc motors, a two-pass gear-reduction system, and a roller screw for rotary-to-linear motion conversion. System control is furnished by a solid-state electronic controller and power supply; a pair of resolvers deliver position feedback to the controller, such that precise positioning is achieved. Peformance comparisons have been conducted between the EMA and comparable-performance hydraulic systems applicable to TVCs.

  17. Design and application of electromechanical actuators for deep space missions

    NASA Technical Reports Server (NTRS)

    Haskew, Tim A.; Wander, John

    1995-01-01

    This third semi-annual progress report covers the reporting period from August 16, 1994 through February 15, 1995 on NASA Grant NAG8-240, 'Design and Application of Electromechanical Actuators for Deep Space Missions'. There are two major report sections: Motor Control Status/Electrical Experiment Planning and Experiment Planning and Initial Results. The primary emphasis of our efforts during the reporting period has been final construction and testing of the laboratory facilities. As a result, this report is dedicated to that topic.

  18. Electro-mechanical sensing in freestanding monolayered gold nanoparticle membranes

    NASA Astrophysics Data System (ADS)

    Gauvin, M.; Grisolia, J.; Alnasser, T.; Viallet, B.; Xie, S.; Brugger, J.; Ressier, L.

    2016-06-01

    The electro-mechanical sensing properties of freestanding monolayered membranes of dodecanethiol coated 7 nm gold nanoparticles (NPs) are investigated using AFM force spectroscopy and conductive AFM simultaneously. The electrical resistance of the NP membranes increases sensitively with the point-load force applied in the center of the membranes using an AFM tip. Numerical simulations of electronic conduction in a hexagonally close-packed two-dimensional (2D) array of NPs under point load-deformation are carried out on the basis of electronic transport measurements at low temperatures and strain modeling of the NP membranes by finite element analysis. These simulations, supporting AFM-based electro-mechanical measurements, attribute the high strain sensitivity of the monolayered NP membranes to the exponential dependence of the tunnel electron transport in 2D NP arrays on the strain-induced length variation of the interparticle junctions. This work thus evidences a new class of highly sensitive nano-electro-mechanical systems based on freestanding monolayered gold NP membranes.The electro-mechanical sensing properties of freestanding monolayered membranes of dodecanethiol coated 7 nm gold nanoparticles (NPs) are investigated using AFM force spectroscopy and conductive AFM simultaneously. The electrical resistance of the NP membranes increases sensitively with the point-load force applied in the center of the membranes using an AFM tip. Numerical simulations of electronic conduction in a hexagonally close-packed two-dimensional (2D) array of NPs under point load-deformation are carried out on the basis of electronic transport measurements at low temperatures and strain modeling of the NP membranes by finite element analysis. These simulations, supporting AFM-based electro-mechanical measurements, attribute the high strain sensitivity of the monolayered NP membranes to the exponential dependence of the tunnel electron transport in 2D NP arrays on the strain

  19. Numerical Evaluation of Strain Rate Effect on Mechanical and Electromechanical Coupling Responses in BaTiO3 Single-Crystal Nanofilm

    NASA Astrophysics Data System (ADS)

    Tian, Xiao Bao; Yang, Xin Hua; Cao, Wei Zhong

    2014-02-01

    The mechanical and electromechanical coupling responses of a ferroelectric single-crystal nanofilm under displacement loading at different strain rates have been simulated using the molecular dynamics method based on the shell model. While the linear stress-strain relation is independent of the strain rate, strong strain rate dependence is exhibited in the electromechanical coupling response for strain rates between 0 ns-1 and 0.5 ns-1. There is an approximate semilogarithmic linear relationship between the polarization stability strain and the strain rate. With increasing strain rate, local 180° domain switches take place sequentially from inside to outside in the stable domain structure evolution, and the number of domain walls increases. However, after the strain rate exceeds 0.5 ns-1, it has almost no effect on the␣domain structure. This work is helpful for improving ferroelectric device design and expanding ferroelectric application fields.

  20. Stretchable and transparent electrodes based on patterned silver nanowires by laser-induced forward transfer for non-contacted printing techniques

    NASA Astrophysics Data System (ADS)

    Araki, Teppei; Mandamparambil, Rajesh; Martinus Peterus van Bragt, Dirk; Jiu, Jinting; Koga, Hirotaka; van den Brand, Jeroen; Sekitani, Tsuyoshi; den Toonder, Jaap M. J.; Suganuma, Katsuaki

    2016-11-01

    Silver nanowires (AgNWs) are excellent candidate electrode materials in next-generation wearable devices due to their high flexibility and high conductivity. In particular, patterning techniques for AgNWs electrode manufacture are very important in the roll-to-roll printing process to achieve high throughput and special performance production. It is also essential to realize a non-contact mode patterning for devices in order to keep the pre-patterned components away from mechanical damages. Here, we report a successful non-contact patterning of AgNWs-based stretchable and transparent electrodes by laser-induced forward transfer (LIFT) technique. The technique was used to fabricate a 100% stretchable electrode with a width of 200 μm and electrical resistivity 10‑4 Ωcm. Experiments conducted integrating the stretchable electrode on rubber substrate in which LED was pre-fabricated showed design flexibility resulting from non-contact printing. Further, a patterned transparent electrode showed over 80% in optical transmittance and less than 100 Ω sq‑1 in sheet resistance by the optimized LIFT technique.

  1. Calculating frequency at loads in simulations of electro-mechanical transients

    SciTech Connect

    Nutaro, James J; Protopopescu, Vladimir A

    2012-01-01

    This paper introduces a new method for calculating frequency at an electrical load in simulations of electro-mechanical transients. The method is designed for simulation studies that require accurate models of sensors such as phasor measurement units and F-Net devices, which measure frequency at locations away from generating plants. These sensors are poised to become critical components in the control systems of electrical power grids, and therefore simulation tools that incorporate accurate models of these devices are essential. The method proposed here corrects two drawbacks of using numerically computed phase angle derivatives to approximate frequency. First, it eliminates spurious spikes in frequencies calculated at loads. Second, it eliminates instabilities induced by the simulator in studies of frequency responsive loads. The proposed method is derived from a simplified model of the generators and loads in an electrical system, but in the final analysis does not depend critically on these simplifications and is therefore applicable to more sophisticated models. The method is demonstrated with the simplified model applied to the IEEE 14 and 300 bus systems.

  2. Self-sensing ionic electromechanically active actuator with patterned carbon electrodes

    NASA Astrophysics Data System (ADS)

    Kruusamäe, Karl; Kaasik, Friedrich; Punning, Andres; Aabloo, Alvo

    2013-04-01

    In comparison to other ionic electromechanically active polymers (ionic EAP), carbon-polymer composite (CPC) actuators are considered especially attractive due to possibility of producing completely metal-free devices. However, mechanical response of ionic EAP-s is, in addition to voltage and frequency, dependent on environmental variables such as humidity and temperature. Therefore, similarly to other EAPs, one of the major challenges lies in achieving controlled actuation of the CPC sample. Due to their size and added complexity, external feedback devices (e.g. laser displacement sensors and video cameras) tend to inhibit the application of micro-scale actuators. Hence, self-sensing EAP actuators - capable for simultaneous actuation and sensing - are often desired. A thin polyvinylidene fluoride-cohexafluoropropylene film with ionic liquid (EMIMBF4) was prepared and masked coincidently on opposite surfaces prior to spray painting carbide-derived carbon electrodes. The purpose of masking was to create different electrically insulated electrodes on the same surface of polymer in order to achieve separate sections for actuator and sensor on one piece of CPC material. Solution of electrode paint consisting of carbide-derived carbon, EMIMBF4 and dimethylacetamide was applied to the polymer film. After removing the masking tape, a completely metal-free CPC actuator with sophisticated electrode geometry was achieved to foster simultaneous sensing and actuation, i.e. self-sensing carbon-polymer actuator was created.

  3. MEMS and microfluidics for diagnostics devices.

    PubMed

    Rosen, Y; Gurman, P

    2010-06-01

    There are conditions in clinical medicine demanding critical therapeutic decisions. These conditions necessitate accuracy, rapidity, accessibility, cost-effectiveness and mobility. New technologies have been developed in order to address these challenges. Microfluidics and Micro Electro-Mechanical Systems are two of such technologies. Microfluidics, a discipline that involves processing fluids at the microscale in etched microchannels, is being used to build lab- on-a-chip systems to run chemical and biological assays. These systems are being transformed into handheld devices designed to be used at remote settings or at the bedside. MEMS are microscale electromechanical elements integrated in lab chip systems or used as individual components. MEMS based sensors represents a highly developed field with successful commercialized products currently being incorporated into vitro,ex vivo and in vivo devices. In the present paper several examples of microfluidic devices and MEMS sensors are introduced together with some current examples of commercialized products. Future challenges and trends will be discussed. PMID:20199381

  4. Illumination-compensated non-contact imaging photoplethysmography via dual-mode temporally coded illumination

    NASA Astrophysics Data System (ADS)

    Amelard, Robert; Scharfenberger, Christian; Wong, Alexander; Clausi, David A.

    2015-03-01

    Non-contact camera-based imaging photoplethysmography (iPPG) is useful for measuring heart rate in conditions where contact devices are problematic due to issues such as mobility, comfort, and sanitation. Existing iPPG methods analyse the light-tissue interaction of either active or passive (ambient) illumination. Many active iPPG methods assume the incident ambient light is negligible to the active illumination, resulting in high power requirements, while many passive iPPG methods assume near-constant ambient conditions. These assumptions can only be achieved in environments with controlled illumination and thus constrain the use of such devices. To increase the number of possible applications of iPPG devices, we propose a dual-mode active iPPG system that is robust to changes in ambient illumination variations. Our system uses a temporally-coded illumination sequence that is synchronized with the camera to measure both active and ambient illumination interaction for determining heart rate. By subtracting the ambient contribution, the remaining illumination data can be attributed to the controlled illuminant. Our device comprises a camera and an LED illuminant controlled by a microcontroller. The microcontroller drives the temporal code via synchronizing the frame captures and illumination time at the hardware level. By simulating changes in ambient light conditions, experimental results show our device is able to assess heart rate accurately in challenging lighting conditions. By varying the temporal code, we demonstrate the trade-off between camera frame rate and ambient light compensation for optimal blood pulse detection.

  5. Troubleshooting of an Electromechanical System (Westinghouse PLC Controlling a Pneumatic Robot). High-Technology Training Module.

    ERIC Educational Resources Information Center

    Tucker, James D.

    This training module on the troubleshooting of an electromechanical system, The Westinghouse Programmable Logic Controller (PLC) controlling a pneumatic robot, is used for a troubleshooting unit in an electromechanical systems/robotics and automation systems course. In this unit, students locate and repair a defect in a PLC-operated machine. The…

  6. Electro-mechanical sensing in freestanding monolayered gold nanoparticle membranes.

    PubMed

    Gauvin, M; Grisolia, J; Alnasser, T; Viallet, B; Xie, S; Brugger, J; Ressier, L

    2016-06-01

    The electro-mechanical sensing properties of freestanding monolayered membranes of dodecanethiol coated 7 nm gold nanoparticles (NPs) are investigated using AFM force spectroscopy and conductive AFM simultaneously. The electrical resistance of the NP membranes increases sensitively with the point-load force applied in the center of the membranes using an AFM tip. Numerical simulations of electronic conduction in a hexagonally close-packed two-dimensional (2D) array of NPs under point load-deformation are carried out on the basis of electronic transport measurements at low temperatures and strain modeling of the NP membranes by finite element analysis. These simulations, supporting AFM-based electro-mechanical measurements, attribute the high strain sensitivity of the monolayered NP membranes to the exponential dependence of the tunnel electron transport in 2D NP arrays on the strain-induced length variation of the interparticle junctions. This work thus evidences a new class of highly sensitive nano-electro-mechanical systems based on freestanding monolayered gold NP membranes. PMID:27194578

  7. Design and application of electromechanical actuators for deep space missions

    NASA Astrophysics Data System (ADS)

    Haskew, Tim A.; Wander, John

    1993-09-01

    The annual report Design and Application of Electromechanical Actuators for Deep Space Missions is presented. The reporting period is 16 Aug. 1992 to 15 Aug. 1993. However, the primary focus will be work performed since submission of our semi-annual progress report in Feb. 1993. Substantial progress was made. We currently feel confident in providing guidelines for motor and control strategy selection in electromechanical actuators to be used in thrust vector control (TVC) applications. A small portion was presented in the semi-annual report. At this point, we have implemented highly detailed simulations of various motor/drive systems. The primary motor candidates were the brushless dc machine, permanent magnet synchronous machine, and the induction machine. The primary control implementations were pulse width modulation and hysteresis current control. Each of the two control strategies were applied to each of the three motor choices. With either pulse width modulation or hysteresis current control, the induction machine was always vector controlled. A standard test position command sequence for system performance evaluation is defined. Currently, we are gathering all of the necessary data for formal presentation of the results. Briefly stated for TVC application, we feel that the brushless dc machine operating under PWM current control is the best option. Substantial details on the topic, with supporting simulation results, will be provided later, in the form of a technical paper prepared for submission and also in the next progress report with more detail than allowed for paper publication.

  8. An electromechanical model of neuronal dynamics using Hamilton's principle

    PubMed Central

    Drapaca, Corina S.

    2015-01-01

    Damage of the brain may be caused by mechanical loads such as penetration, blunt force, shock loading from blast, and by chemical imbalances due to neurological diseases and aging that trigger not only neuronal degeneration but also changes in the mechanical properties of brain tissue. An understanding of the interconnected nature of the electro-chemo-mechanical processes that result in brain damage and ultimately loss of functionality is currently lacking. While modern mathematical models that focus on how to link brain mechanics to its biochemistry are essential in enhancing our understanding of brain science, the lack of experimental data required by these models as well as the complexity of the corresponding computations render these models hard to use in clinical applications. In this paper we propose a unified variational framework for the modeling of neuronal electromechanics. We introduce a constrained Lagrangian formulation that takes into account Newton's law of motion of a linear viscoelastic Kelvin–Voigt solid-state neuron as well as the classic Hodgkin–Huxley equations of the electronic neuron. The system of differential equations describing neuronal electromechanics is obtained by applying Hamilton's principle. Numerical simulations of possible damage dynamics in neurons will be presented. PMID:26236195

  9. Electromechanical impedance response of a cracked Timoshenko beam.

    PubMed

    Zhang, Yuxiang; Xu, Fuhou; Chen, Jiazhao; Wu, Cuiqin; Wen, Dongdong

    2011-01-01

    Typically, the Electromechanical Impedance (EMI) technique does not use an analytical model for basic damage identification. However, an accurate model is necessary for getting more information about any damage. In this paper, an EMI model is presented for predicting the electromechanical impedance of a cracked beam structure quantitatively. A coupled system of a cracked Timoshenko beam with a pair of PZT patches bonded on the top and bottom surfaces has been considered, where the bonding layers are assumed as a Kelvin-Voigt material. The shear lag model is introduced to describe the load transfer between the PZT patches and the beam structure. The beam crack is simulated as a massless torsional spring; the dynamic equations of the coupled system are derived, which include the crack information and the inertial forces of both PZT patches and adhesive layers. According to the boundary conditions and continuity conditions, the analytical expression of the admittance of PZT patch is obtained. In the case study, the influences of crack and the inertial forces of PZT patches are analyzed. The results show that: (1) the inertial forces affects significantly in high frequency band; and (2) the use of appropriate frequency range can improve the accuracy of damage identification. PMID:22164017

  10. Nanotechnology in Auditory Research: Membrane Electromechanics in Hearing

    PubMed Central

    Araya, Mussie; Brownell, William E.

    2016-01-01

    The soft, thin membranes that envelop all living cells are 2D, nanoscale, fluid assemblies of phospholipids, sterols, proteins and other molecules. Mechanical interactions between these components facilitate membrane function, a key example of which is ion flow mediated by the mechanical opening and closing of channels. Hearing and balance are initiated by the modulation of ion flow through mechanoreceptor channels in stereocilia membranes. Cochlear amplification by the outer hair cell involves modulation of ion movement by the membrane protein prestin. Voltage gated ion channels shape the receptor potential in hair cells and are responsible for the initiation of action potentials that are at the heart of sensory processing in the brain. All three processes require a membrane and their kinetics are modulated by the mechanical (ie. material) properties of the membrane. This chapter reviews the methodology for measuring the mechanics of cellular membranes and introduces a method for examining membrane electromechanics. The approach allows examination of electromechanically mediated interactions between the different molecular species in the membrane that contribute to the biology of hearing and balance. PMID:27259937

  11. Electromechanical properties of zigzag-shaped carbon nanotubes.

    PubMed

    Liu, Lizhao; Gao, Junfeng; Guo, Xu; Zhao, Jijun

    2013-10-28

    Atomic structural models of zigzag-shaped carbon nanotubes (Z-CNTs) were constructed by periodically introducing pentagons and heptagons into pristine CNTs. In terms of formation energies, the Z-CNTs present comparable energetic stabilities to those of the pristine CNTs and are more stable than C60 fullerene. The mechanical properties of these Z-CNTs, including the Young's modulus, intrinsic strength and failure behaviour, were systematically investigated by first-principles computations. Compared with the pristine CNTs with an average Young's modulus of about 1.0 TPa, incorporation of pentagons and heptagons in the Z-CNTs will reduce the average Young's modulus to several hundreds of GPa. Moreover, the computational results also showed that under uniaxial tensile strain, the intrinsic strength and failure strain of the Z-CNTs are also lower than those of the pristine CNTs. Generally, the Young's modulus and intrinsic strength of the Z-CNTs are exponentially inverse to curvature, which can be expressed by simple formulae. In particular, the electronic properties of the armchair Z-CNTs can be tailored by uniaxial tensile strain. It was also found that through applying tensile strain, a semiconductor-metal or metal-semiconductor transition can be triggered. The localized-delocalized partial charge distribution near the Fermi energy for the strained Z-CNTs can explain the semiconductor-metal or metal-semiconductor transition. This significant electromechanical coupling effect suggests the Z-CNTs have potential applications in nanoscale electromechanical sensors and switches.

  12. An electromechanical model of neuronal dynamics using Hamilton's principle.

    PubMed

    Drapaca, Corina S

    2015-01-01

    Damage of the brain may be caused by mechanical loads such as penetration, blunt force, shock loading from blast, and by chemical imbalances due to neurological diseases and aging that trigger not only neuronal degeneration but also changes in the mechanical properties of brain tissue. An understanding of the interconnected nature of the electro-chemo-mechanical processes that result in brain damage and ultimately loss of functionality is currently lacking. While modern mathematical models that focus on how to link brain mechanics to its biochemistry are essential in enhancing our understanding of brain science, the lack of experimental data required by these models as well as the complexity of the corresponding computations render these models hard to use in clinical applications. In this paper we propose a unified variational framework for the modeling of neuronal electromechanics. We introduce a constrained Lagrangian formulation that takes into account Newton's law of motion of a linear viscoelastic Kelvin-Voigt solid-state neuron as well as the classic Hodgkin-Huxley equations of the electronic neuron. The system of differential equations describing neuronal electromechanics is obtained by applying Hamilton's principle. Numerical simulations of possible damage dynamics in neurons will be presented.

  13. (Electro)Mechanical Properties of Olefinic Block Copolymers

    NASA Astrophysics Data System (ADS)

    Spontak, Richard

    2014-03-01

    Conventional styrenic triblock copolymers (SBCs) swollen with a midblock-selective oil have been previously shown to exhibit excellent electromechanical properties as dielectric elastomers. In this class of electroactive polymers, compliant electrodes applied as active areas to opposing surfaces of an elastomer attract each other, and thus compress the elastomer due to the onset of a Maxwell stress, upon application of an external electric field. This isochoric process is accompanied by an increase in lateral area, which yields the electroactuation strain (measuring beyond 300% in SBC systems). Performance parameters such as the Maxwell stress, transverse strain, dielectric breakdown, energy density and electromechanical efficiency are determined directly from the applied electric field and resulting electroactuation strain. In this study, the same principle used to evaluate SBC systems is extended to olefinic block copolymers (OBCs), which can be described as randomly-coupled multiblock copolymers that consist of crystallizable polyethylene hard segments and rubbery poly(ethylene-co-octene) soft segments. Considerations governing the development of a methodology to fabricate electroresponsive OBC systems are first discussed for several OBCs differing in composition and bulk properties. Evidence of electroactuation in selectively-solvated OBC systems is presented and performance metrics measured therefrom are quantitatively compared with dielectric elastomers derived from SBC and related materials.

  14. Design and application of electromechanical actuators for deep space missions

    NASA Technical Reports Server (NTRS)

    Haskew, Tim A.; Wander, John

    1993-01-01

    The annual report Design and Application of Electromechanical Actuators for Deep Space Missions is presented. The reporting period is 16 Aug. 1992 to 15 Aug. 1993. However, the primary focus will be work performed since submission of our semi-annual progress report in Feb. 1993. Substantial progress was made. We currently feel confident in providing guidelines for motor and control strategy selection in electromechanical actuators to be used in thrust vector control (TVC) applications. A small portion was presented in the semi-annual report. At this point, we have implemented highly detailed simulations of various motor/drive systems. The primary motor candidates were the brushless dc machine, permanent magnet synchronous machine, and the induction machine. The primary control implementations were pulse width modulation and hysteresis current control. Each of the two control strategies were applied to each of the three motor choices. With either pulse width modulation or hysteresis current control, the induction machine was always vector controlled. A standard test position command sequence for system performance evaluation is defined. Currently, we are gathering all of the necessary data for formal presentation of the results. Briefly stated for TVC application, we feel that the brushless dc machine operating under PWM current control is the best option. Substantial details on the topic, with supporting simulation results, will be provided later, in the form of a technical paper prepared for submission and also in the next progress report with more detail than allowed for paper publication.

  15. Nanotechnology in Auditory Research: Membrane Electromechanics in Hearing.

    PubMed

    Araya, Mussie; Brownell, William E

    2016-01-01

    The soft, thin membranes that envelop all living cells are 2D, nanoscale, fluid assemblies of phospholipids, sterols, proteins, and other molecules. Mechanical interactions between these components facilitate membrane function, a key example of which is ion flow mediated by the mechanical opening and closing of channels. Hearing and balance are initiated by the modulation of ion flow through mechanoreceptor channels in stereocilia membranes. Cochlear amplification by the outer hair cell involves modulation of ion movement by the membrane protein prestin. Voltage-gated ion channels shape the receptor potential in hair cells and are responsible for the initiation of action potentials that are at the heart of sensory processing in the brain. All three processes require a membrane and their kinetics are modulated by the mechanical (i.e., material) properties of the membrane. This chapter reviews the methodology for measuring the mechanics of cellular membranes and introduces a method for examining membrane electromechanics. The approach allows examination of electromechanically mediated interactions between the different molecular species in the membrane that contribute to the biology of hearing and balance. PMID:27259937

  16. Optical device for straightness measurement

    NASA Astrophysics Data System (ADS)

    Vekteris, Vladas; Jurevicius, Mindaugas; Turla, Vytautas

    2015-11-01

    The present paper describes the research of the optical device for two-dimensional straightness measurement of technological machines. Mathematical study of an optical device, operating on the phase principle and measuring transversal displacements of machine parts in two directions ( X and Y) during their linear longitudinal motion in a machine (alongside the Z axis), is presented. How to estimate the range of travel along the Z axis is analytically shown. At this range, the measurer gives correct measurements of transverse displacement. The necessary distance from the objective focus to the image plane was defined mathematically. The sample results of measuring the displacement of the table of a technological machine by using the optical device are presented in the paper. This optical device for non-contact straightness measurement can be used for measurement straightness in turning, milling, drilling, grinding machines and other technological machines, also in geodesy and cartography, and for moving accuracy testing of mechatronic devices, robotics and others.

  17. Electro-Mechanical Systems for Extreme Space Environments

    NASA Technical Reports Server (NTRS)

    Mojarradi, Mohammad M.; Tyler, Tony R.; Abel, Phillip B.; Levanas, Greg

    2011-01-01

    Exploration beyond low earth orbit presents challenges for hardware that must operate in extreme environments. The current state of the art is to isolate and provide heating for sensitive hardware in order to survive. However, this protection results in penalties of weight and power for the spacecraft. This is particularly true for electro-mechanical based technology such as electronics, actuators and sensors. Especially when considering distributed electronics, many electro-mechanical systems need to be located in appendage type locations, making it much harder to protect from the extreme environments. The purpose of this paper to describe the advances made in the area of developing electro-mechanical technology to survive these environments with minimal protection. The Jet Propulsion Lab (JPL), the Glenn Research Center (GRC), the Langley Research Center (LaRC), and Aeroflex, Inc. over the last few years have worked to develop and test electro-mechanical hardware that will meet the stringent environmental demands of the moon, and which can also be leveraged for other challenging space exploration missions. Prototype actuators and electronics have been built and tested. Brushless DC actuators designed by Aeroflex, Inc have been tested with interface temperatures as low as 14 degrees Kelvin. Testing of the Aeroflex design has shown that a brushless DC motor with a single stage planetary gearbox can operate in low temperature environments for at least 120 million cycles (measured at motor) if long life is considered as part of the design. A motor control distributed electronics concept developed by JPL was built and operated at temperatures as low as -160 C, with many components still operational down to -245 C. Testing identified the components not capable of meeting the low temperature goal of -230 C. This distributed controller is universal in design with the ability to control different types of motors and read many different types of sensors. The controller

  18. Studies on the Evaluation Methods for the Food Quality with a Non-contact type Capacitance Sensor.

    NASA Astrophysics Data System (ADS)

    Narumiya, Tadaoki; Hagura, Yoshio

    Changes of capacitance and temperature of ethyl alcohol, hamburger and dough with cheese filling were measured with specially-made measuring devices during the freezing and thawing. The results of measurement of capacitance and temperature suggest a linear correlation for ethyl alcohol as a single constituent substance. The adequate correlation is too estimated from the results of food samples, though the capacitance of food sample varies greatly at the start and end of freezing and thawing process. It has been demonstrated that the quality or physical condition of food sample can be determined easily by the measurement of capacitance using the specially-made devices. Also the quality or physical condition of food can be determined easily by the non-contact and non-destructive measurements of capacitance. A variety application of the present technique is conceivable for the process control of the freezing and thawing foods.

  19. Impacting device for testing insulation

    NASA Technical Reports Server (NTRS)

    Redmon, J. W. (Inventor)

    1984-01-01

    An electro-mechanical impacting device for testing the bonding of foam insulation to metal is descirbed. The device lightly impacts foam insulation attached to metal to determine whether the insulation is properly bonded to the metal and to determine the quality of the bond. A force measuring device, preferably a load cell mounted on the impacting device, measures the force of the impact and the duration of the time the hammer head is actually in contact with the insulation. The impactor is designed in the form of a handgun having a driving spring which can propel a plunger forward to cause a hammer head to impact the insulation. The device utilizes a trigger mechanism which provides precise adjustements, allowing fireproof operation.

  20. EDITORIAL: High-resolution noncontact atomic force microscopy High-resolution noncontact atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Pérez, Rubén; García, Ricardo; Schwarz, Udo

    2009-06-01

    Progress in nanoscience and nanotechnology requires tools that enable the imaging and manipulation of matter at the atomic and molecular scale. During the last two decades or so, scanning probe-based techniques have proven to be particularly versatile in this regard. Among the various probe-based approaches, atomic force microscopy (AFM) stands out in many ways, including the total number of citations and the breadth of possible applications, ranging from materials characterization to nanofabrication and biological studies. However, while nanometer scale operation in different environments became routine, atomic resolution imaging remained elusive for a long time. The reason for this initial deficiency was that contact with the sample blunts atomically sharp tips, which are mandatory for successful atomic resolution imaging. This problem was overcome in the mid-1990s with the introduction of noncontact atomic force microscopy (NC-AFM), which represents a version of AFM where the cantilever is oscillated close to the sample surface without actually 'touching' it. This allows the preservation of the atomic sharpness of the tip while interaction-induced changes in the cantilever's resonance frequency are used to quantify the tip-sample distance. Since then, progress has been steady and includes the development of commercial instruments as well as the addition of many new capabilities beyond imaging, such as the identification and manipulation of individual atoms. A series of annual international conferences, starting in Osaka in 1998, have contributed significantly to this outstanding performance. The program of the most recent conference from this series, held in Madrid on 15-19 September 2008, reflects the maturity of this field, with an increasing number of groups developing strong activities that involve novel approaches and applications covering areas well beyond the original vacuum-based imaging. In this special issue of Nanotechnology we present a selection of

  1. Dielectric fluctuations in force microscopy: noncontact friction and frequency jitter.

    PubMed

    Yazdanian, Showkat M; Marohn, John A; Loring, Roger F

    2008-06-14

    Electric force microscopy, in which a charged probe oscillates tens to hundreds of nanometers above a sample surface, provides direct mechanical detection of relaxation in molecular materials. Noncontact friction, the damping of the probe's motions, reflects the dielectric function at the resonant frequency of the probe, while fluctuations in the probe frequency are induced by slower molecular motions. We present a unified theoretical picture of both measurements, which relates the noncontact friction and the power spectrum of the frequency jitter to dielectric properties of the sample and to experimental geometry. Each observable is related to an equilibrium correlation function associated with electric field fluctuations, which is determined by two alternative, complementary strategies for a dielectric continuum model of the sample. The first method is based on the calculation of a response function associated with the polarization of the dielectric by a time-varying external charge distribution. The second approach employs a stochastic form of Maxwell's equations, which incorporate a fluctuating electric polarization, to compute directly the equilibrium correlation function in the absence of an external charge distribution. This approach includes effects associated with the propagation of radiation. In the experimentally relevant limit that the tip-sample distance is small compared to pertinent wavelengths of radiation, the two methods yield identical results. Measurements of the power spectrum of frequency fluctuations of an ultrasensitive cantilever together with measurements of the noncontact friction over a poly(methylmethacrylate) film are used to estimate the minimum experimentally detectable frequency jitter. The predicted jitter for this polymer is shown to exceed this threshold, demonstrating the feasibility of the measurement. PMID:18554042

  2. Non-contact photoacoustic tomography with a laser Doppler vibrometer

    NASA Astrophysics Data System (ADS)

    Xu, Guan; Wang, Cheng; Feng, Ting; Oliver, David E.; Wang, Xueding

    2014-03-01

    Most concurrent photoacoustic tomography systems are based on traditional ultrasound measurement regime, which requires the contact or acoustic coupling material between the biological tissue and the ultrasound transducer. This study investigates the feasibility of non-contact measurement of photacoustic signals generated inside biomedical tissues by observing the vibrations at the surface of the tissues with a commercial laser Doppler vibrometer. The vibrometer with 0- 2MHz measurement bandwidth and 5 MHz sampling frequency was integrated to a conventional rotational PAT data acquisition system. The data acquisition of the vibrometer was synchronized to the laser illumination from an Nd:YAG laser with output at 532nm. The laser energy was tuned to 17.5mJ per square centimeter. The PA signals were acquired at 120 angular locations uniformly distributed around the scanned objects. The frequency response of the measurement system was first calibrated. 2-inch-diamater cylindrical phantoms containing small rubber plates and biological tissues were afterwards imaged. The phantoms were made from 5% intralipid solution in 10% porcine gelatin to simulate the light scattering in biological tissue and to backscatter the measurement laser from the vibrometer. Time-domain backprojection method was used for the image reconstruction. Experiments with real-tissue phantoms show that with laser illumination of 17.5 mJ/cm2 at 532 nm, the non-contact photoacoustic (PA) imaging system with 15dB detection bandwidth of 2.5 MHz can resolve spherical optical inclusions with dimension of 500μm and multi-layered structure with optical contrast in strongly scattering medium. The experiment results prompt the potential implementation of the non-contact PAT to achieve "photoacoustic camera".

  3. Dielectric and Electromechanical Properties of Polyurethane and Polydimethylsiloxane Blends and their Nanocomposites

    NASA Astrophysics Data System (ADS)

    Cakmak, Enes

    Conventional means of converting electrical energy to mechanical work are generally considered too noisy and bulky for many contemporary technologies such as microrobotic, microfluidic, and haptic devices. Dielectric electroactive polymers (D-EAPs) constitude a growing class of electroactive polymers (EAP) that are capable of producing mechanica work induced by an applied electric field. D-EAPs are considered remarkably efficient and well suited for a wide range of applications, including ocean-wave energy harvesters and prosthetic devices. However, the real-world application of D-EAPs is very limited due to a number of factors, one of which is the difficulty of producing high actuation strains at acceptably low electric fields. D-EAPs are elastomeric polymers and produce large strain response induced by external electric field. The electromechanical properties of D-EAPs depend on the dielectric properties and mechanical properties of the D-EAP. In terms of dielectric behavior, these actuators require a high dielectric constant, low dielectric loss, and high dielectric strength to produce an improved actuation response. In addition to their dielectric properties, the mechanical properties of D-EAPs, such as elastic moduli and hysteresis, are also of importance. Therefore, material properties are a key feature of D-EAP technology. DE actuator materials reported in the literature cover many types of elastomers and their composites formed with dielectric fillers. Along with polymeric matrix materials, various ceramic, metal, and organic fillers have been employed in enhancing dielectric behavior of DEs. This work describes an effort to characterize elastomer blends and composites of different matrix and dielectric polymer fillers according to their dielectric, mechanical, and electromechanical responses. This dissertation focuses on the development and characterization of polymer-polymer blends and composites from a high-k polyurethane (PU) and polydimethylsiloxane

  4. Noncontact monitoring of cardiorespiratory activity by electromagnetic coupling.

    PubMed

    Teichmann, Daniel; Foussier, Jérôme; Jia, Jing; Leonhardt, Steffen; Walter, Marian

    2013-08-01

    In this paper, the method of noncontact monitoring of cardiorespiratory activity by electromagnetic coupling with human tissue is investigated. Two measurement modalities were joined: an inductive coupling sensor based on magnetic eddy current induction and a capacitive coupling sensor based on displacement current induction. The system's sensitivity to electric tissue properties and its dependence on motion are analyzed theoretically as well as experimentally for the inductive and capacitive coupling path. The potential of both coupling methods to assess respiration and pulse without contact and a minimum of thoracic wall motion was verified by laboratory experiments. The demonstrator was embedded in a chair to enable recording from the back part of the thorax.

  5. Noncontact Measurement Of Shaft Speed, Torque, And Power

    NASA Technical Reports Server (NTRS)

    Madzsar, George C.

    1993-01-01

    Noncontact fiber-optic sensor and associated electronic equipment measure twist and speed of rotation of shaft. Measurements determine torque and power. Response of sensor remains linear even at cryogenic temperatures. Reflective strips on rotating shaft reflect two series of light pulses back into optical system. Bidirectional coupler in each of two optical fiber paths separates reflected light from incident light, sending it to photodiode for output to analog-to-digital converter and computer. Sensor requires no slip rings or telemetry to transfer signals from shaft. Well suited for providing data on performances of turbopumps for such cryogenic fluids as liquid oxygen and liquid hydrogen.

  6. Noncontact Ultrasonic Transport of Liquid Using a Flexural Vibration Plate

    NASA Astrophysics Data System (ADS)

    Ding, Mingjie; Koyama, Daisuke; Nakamura, Kentaro

    2012-09-01

    We have succeeded in the noncontact transportation of ethanol droplets inside a semi cylindrical acoustic waveguide. The waveguide was composed of a vibration bottom plate and a semi cylindrical reflector, and a propagating acoustic field was excited in the waveguide. The droplet was levitated at the nodal position of the standing wave mode in the cross section of the waveguide and transported by the traveling wave component in the horizontal direction. The transportation distance was 65 mm and the terminal velocity reached 2.3 m/s when the droplet was 1.5 mm in diameter and 1.38 g in weight.

  7. Noncontact inspection laser system for characterization of piezoelectric samples

    SciTech Connect

    Jimenez, F.J.; Frutos, J. de

    2004-11-01

    In this work measurements on a piezoelectric sample in dynamic behavior were taken, in particular, around the frequencies of resonance for the sample where the nonlineal effects are accentuated. Dimension changes in the sample need to be studied as that will allow a more reliable characterization of the piezoelectric samples. The goal of this research is to develop an inspection system able to obtain measurements, using a noncontact laser displacement transducer, also able to visualize, in three-dimensional graphic environment, the displacement that takes place in a piezoelectric sample surface. In resonant mode, the vibration mode of the sample is visualized.

  8. A noncontacting motion monitoring system for an astronaut translation aid

    NASA Technical Reports Server (NTRS)

    Finley, Tom D.

    1990-01-01

    The development of a noncontacting motion sensing system designed to monitor the movement of a cart along a track in the low earth orbit space environment is described. The system uses Hall effect sensors to detect the position of small permanent magnets located along the track. The measurement criteria are described, the system design is discussed, and estimates of the system error are given. The system will be used on the Crew and Equipment Translation Aid (CETA) experiment scheduled for the STS37 flight in November 1990. It will allow the position, velocity, and acceleration of the cart to be determined as it moves along the track.

  9. Microelectromechanical reprogrammable logic device

    PubMed Central

    Hafiz, M. A. A.; Kosuru, L.; Younis, M. I.

    2016-01-01

    In modern computing, the Boolean logic operations are set by interconnect schemes between the transistors. As the miniaturization in the component level to enhance the computational power is rapidly approaching physical limits, alternative computing methods are vigorously pursued. One of the desired aspects in the future computing approaches is the provision for hardware reconfigurability at run time to allow enhanced functionality. Here we demonstrate a reprogrammable logic device based on the electrothermal frequency modulation scheme of a single microelectromechanical resonator, capable of performing all the fundamental 2-bit logic functions as well as n-bit logic operations. Logic functions are performed by actively tuning the linear resonance frequency of the resonator operated at room temperature and under modest vacuum conditions, reprogrammable by the a.c.-driving frequency. The device is fabricated using complementary metal oxide semiconductor compatible mass fabrication process, suitable for on-chip integration, and promises an alternative electromechanical computing scheme. PMID:27021295

  10. Microelectromechanical reprogrammable logic device

    NASA Astrophysics Data System (ADS)

    Hafiz, M. A. A.; Kosuru, L.; Younis, M. I.

    2016-03-01

    In modern computing, the Boolean logic operations are set by interconnect schemes between the transistors. As the miniaturization in the component level to enhance the computational power is rapidly approaching physical limits, alternative computing methods are vigorously pursued. One of the desired aspects in the future computing approaches is the provision for hardware reconfigurability at run time to allow enhanced functionality. Here we demonstrate a reprogrammable logic device based on the electrothermal frequency modulation scheme of a single microelectromechanical resonator, capable of performing all the fundamental 2-bit logic functions as well as n-bit logic operations. Logic functions are performed by actively tuning the linear resonance frequency of the resonator operated at room temperature and under modest vacuum conditions, reprogrammable by the a.c.-driving frequency. The device is fabricated using complementary metal oxide semiconductor compatible mass fabrication process, suitable for on-chip integration, and promises an alternative electromechanical computing scheme.

  11. Effect of carbon nanofillers on the microstructure and electromechanical properties of electroactive polymers

    NASA Astrophysics Data System (ADS)

    Sigamani, Nirmal Shankar

    Both ionic and electronic electroactive polymers (EAPs) have displayed great potential as actuators. Current ionic EAPs have limited practical application due to their slow response time and their low blocked force; furthermore, their ion transport-based mechanism necessitates the presence of an electrolyte, which complicates issues of packaging and device lifetime. On the other hand, despite the advantages of electronic EAPs such as their efficient electromechanical coupling and relatively rapid response time, there are major obstacles blocking their transition to application as well; most notably, they require high actuation voltages (threshold voltage needed to generate electroactive strain) and they have low blocked stress (the stress at which the actuator stops moving). Hence, the main objective of this study was to develop a new kind of polymer nanocomposite for actuator applications that would exhibit simultaneous improvement in both electromechanical response and strain energy density. As a first step, we investigated the impact of the 2-dimensional GO and reduced GO on the electromechanical response of PVDF, a polar polymer. The 1 wt % reduced-GO-PVDF nanocomposites showed a tremendous improvement in dielectric permittivity and electrical conductivity. The dielectric permittivity at 1 KHz increased almost eight fold, while the electrical conductivity showed an increase of four orders of magnitude in comparison to the corresponding values for the unmodified PVDF. The reduced GO-PVDF polymer films showed a bending actuation response with a DC electric field, thus demonstrating its potential as EAP. The mechanism responsible for this bending actuation response is determined to be electrostriction, because the strain (S11) exhibited a quadratic response with the applied electric field while Joule heating and Maxwell stress effects were shown to be negligible. Although coefficient of electrostriction of reduced GO-PVDF is higher than most of the existing

  12. Non-contact FBG sensing based steam turbine rotor dynamic balance vibration detection system

    NASA Astrophysics Data System (ADS)

    Li, Tianliang; Tan, Yuegang; Cai, Lin

    2015-10-01

    This paper has proposed a non-contact vibration sensor based on fiber Bragg grating sensing, and applied to detect vibration of steam turbine rotor dynamic balance experimental platform. The principle of the sensor has been introduced, as well as the experimental analysis; performance of non-contact FBG vibration sensor has been analyzed in the experiment; in addition, turbine rotor dynamic vibration detection system based on eddy current displacement sensor and non-contact FBG vibration sensor have built; finally, compared with results of signals under analysis of the time domain and frequency domain. The analysis of experimental data contrast shows that: the vibration signal analysis of non-contact FBG vibration sensor is basically the same as the result of eddy current displacement sensor; it verified that the sensor can be used for non-contact measurement of steam turbine rotor dynamic balance vibration.

  13. Initial Evaluation of a New Electromechanical Cooler for Safeguards Applications

    SciTech Connect

    Coleman, RL

    2002-10-21

    The use of liquid nitrogen (LN{sub 2}) constitutes the current state of the art in cryogenic cooling for high-purity germanium (HPGe) detectors, which are widely used for {gamma}-ray and characteristic X-ray spectroscopy because of their excellent energy discrimination. Use of LN{sub 2} requires a liquid nitrogen supply, cumbersome storage tanks and plumbing, and the frequent attention of personnel to be sure that nitrogen levels are sufficient to maintain the detectors at a sufficiently low operating temperature. Safety hazards also are associated with the use of LN{sub 2}, both because of the potential for severe frostbite on exposure to skin and because it displaces ambient oxygen when it evaporates in closed spaces. Existing electromechanical coolers have, until now, been more expensive to procure and maintain than LN{sub 2} systems. Performance and reliability have also been serious issues because of microphonic degradation of photon energy peak resolution and cooler failures due to compressor oil becoming entrained in the refrigerant. This report describes the results of tests of a new HPGe detector cooling technology, the PerkinElmer ORTEC{reg_sign} Products X-Cooler{trademark} that, according to the manufacturer, significantly reduces the lifetime cost of the cooling system without degradation of the output signal. The manufacturer claims to have overcome cost, performance and reliability problems of older-generation electromechanical coolers, but the product has no significant history of use, and this project is the first independent evaluation of its performance for Total cost savings for the DOE and other agencies that use HPGe systems extensively for safeguards monitoring is expected to be quite significant if the new electromechanical cooler technology is shown to be reliable and if performance characteristics indicate its usefulness for this application. The technology also promises to make HPGe monitoring, characterization and detection available for

  14. Design and fabrication of a flexible MEMS-based electro-mechanical sensor array for breast cancer diagnosis

    NASA Astrophysics Data System (ADS)

    Pandya, Hardik J.; Park, Kihan; Desai, Jaydev P.

    2015-07-01

    The use of flexible micro-electro-mechanical systems (MEMS)-based devices provides a unique opportunity in bio-medical robotics such as the characterization of normal and malignant tissues. This paper reports on the design and development of a flexible MEMS-based sensor array integrating mechanical and electrical sensors on the same platform to enable the study of the change in electro-mechanical properties of benign and cancerous breast tissues. In this work, we present the analysis of the electrical characterization of the tissue specimens and also demonstrate the feasibility of using the sensor for the mechanical characterization of tissue specimens. Eight strain gauges acting as mechanical sensors were fabricated using poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) conducting polymer on poly(dimethylsiloxane) (PDMS) as the substrate material. Eight electrical sensors were fabricated using SU-8 pillars on gold (Au) pads which were patterned on the strain gauges separated by a thin insulator (SiO2 1.0 μm). These pillars were coated with gold to make them conducting. The electro-mechanical sensors are integrated on the same substrate. The sensor array covers a 180 μm  ×  180 μm area and the size of the complete device is 20 mm in diameter. The diameter of each breast tissue core used in the present study was 1 mm and the thickness was 8 μm. The region of interest was 200 μm  ×  200 μm. A microindentation technique was used to characterize the mechanical properties of the breast tissues. The sensor is integrated with conducting SU-8 pillars to study the electrical property of the tissue. Through electro-mechanical characterization studies using this MEMS-based sensor, we were able to measure the accuracy of the fabricated device and ascertain the difference between benign and cancers breast tissue specimens.

  15. High-efficiency interferometer for noncontact detection of ultrasounds

    NASA Astrophysics Data System (ADS)

    Czarnek, Robert; Yu, Chin-Jye; Dax, F. R.

    1995-06-01

    Semi-solid metalworking (SSM) incorporates elements of both casting and forging for the manufacture of near-net shape discrete parts. The SSM process capitalizes on thixotropy, a physical state wherein a partially molten material behaves like a fluid when a shear stress is applied. Effective process control depends on the accurate measurement of the ratio between solid and liquid in the feedstock. Due to the high temperature of the material, only noncontact measurements are practical. Surface temperature measurements are not reliable and do not give accurate readings of the bulk material temperature. Since the speed of sound changes during the transition from the solid to the liquid state, ultrasonics offers the potential to determine when a material becomes semi-solid. This paper summarizes attempts to use this change as the means of measuring the solid fraction of semi-solid feedstock. A real time solid fraction sensor system using noncontact laser ultrasonics was developed to measure the SSM material's solid fraction during heating. The system includes a high power Nd:Yag laser for ultrasound generation and a Fabry-Perot interferometer for receiving. The interferometer was optimized for maximum light efficiency and for immunity to the electro-magnetic noise generated by the induction furnaces used in heating the SSM billets. Tests have demonstrated excellent signal to noise ratio at room temperature and at temperatures up to 579 degrees C. A summary of the test results is presented.

  16. Noncontact imaging photoplethysmography to effectively access pulse rate variability

    NASA Astrophysics Data System (ADS)

    Sun, Yu; Hu, Sijung; Azorin-Peris, Vicente; Kalawsky, Roy; Greenwald, Stephen

    2013-06-01

    Noncontact imaging photoplethysmography (PPG) can provide physiological assessment at various anatomical locations with no discomfort to the patient. However, most previous imaging PPG (iPPG) systems have been limited by a low sample frequency, which restricts their use clinically, for instance, in the assessment of pulse rate variability (PRV). In the present study, plethysmographic signals are remotely captured via an iPPG system at a rate of 200 fps. The physiological parameters (i.e., heart and respiration rate and PRV) derived from the iPPG datasets yield statistically comparable results to those acquired using a contact PPG sensor, the gold standard. More importantly, we present evidence that the negative influence of initial low sample frequency could be compensated via interpolation to improve the time domain resolution. We thereby provide further strong support for the low-cost webcam-based iPPG technique and, importantly, open up a new avenue for effective noncontact assessment of multiple physiological parameters, with potential applications in the evaluation of cardiac autonomic activity and remote sensing of vital physiological signs.

  17. Non-Contact EDDY Current Hole Eccentricity and Diameter Measurement

    NASA Technical Reports Server (NTRS)

    Chern, E. James

    1998-01-01

    Precision holes are among the most critical features of a mechanical component. Deviations from permissible tolerances can impede operation and result in unexpected failure. We have developed an automated non-contact eddy current hole diameter and eccentricity measuring system. The operating principle is based on the eddy current lift-off effect, which is the coil impedance as a function of the distance between the coil and the test object. An absolute eddy current probe rotates in the hole. The impedance of each angular position is acquired and input to the computer for integration and analysis. The eccentricity of the hole is the profile of the impedance as a function of angular position as compared to a straight line, an ideal hole. The diameter of the hole is the sum of the diameter of the probe and twice the distance-calibrated impedance. An eddy current image is generated by integrating angular scans for a plurality of depths between the top and bottom to display the eccentricity profile. This system can also detect and image defects in the hole. The method for non-contact eddy current hole diameter and eccentricity measurement has been granted a patent by the U.S. Patent and Trademark Office.

  18. Microwave sensor design for noncontact process monitoring at elevated temperature

    NASA Astrophysics Data System (ADS)

    Yadam, Yugandhara Rao; Arunachalam, Kavitha

    2016-02-01

    In this work we present a microwave sensor for noncontact monitoring of liquid level at high temperatures. The sensor is a high gain, directional conical lensed horn antenna with narrow beam width (BW) designed for operation over 10 GHz - 15 GHz. Sensor design and optimization was carried out using 3D finite element method based electromagnetic (EM) simulation software HFSS®. A rectangular to circular waveguide feed was designed to convert TE10 to TE11 mode for wave propagation in the conical horn. Swept frequency simulations were carried out to optimize antenna flare angle and length to achieve better than -10 dB return loss (S11), standing wave ratio (SWR) less than 2.0, 20° half power BW (HPBW) and 15 dB gain over 10 GHz - 15 GHz. The sensor was fabricated using Aluminum and was characterized in an anechoic test box using a vector network analyzer (E5071C, Agilent Technologies, USA). Experimental results of noncontact level detection are presented for boiling water in a metal canister.

  19. Noncontact detection of ultrasonic waves using fiber optic Sagnac interferometer.

    PubMed

    Jang, Tae Seong; Lee, Seung Seok; Kwon, Il Bum; Lee, Wang Joo; Lee, Jung Ju

    2002-06-01

    This paper describes a fiber optic sensor suitable for noncontact detection of ultrasonic waves. This sensor is based on the fiber optic Sagnac interferometer, which has a path-matched configuration and does not require active stabilization. Quadrature phase bias between two interfering laser beams in the Sagnac loop is applied by controlling the birefringence using a fiber polarization controller. A stable quadrature phase bias can be confirmed by observing the interferometer output according to the change of phase bias. Additional signal processing is not needed for the detection of ultrasonic waves using the Sagnac interferometer. Ultrasonic oscillations produced by conventional ultrasonic piezoelectric transducers were successfully detected, and the performance of this interferometer was investigated by a power spectrum analysis of the output signal. Based on the validation of the fiber optic Sagnac interferometer, noncontact detection of laser-generated surface waves was performed. The configured Sagnac interferometer is very effective for the detection of small displacement with high frequency, such as ultrasonic waves used in conventional nondestructive testing (NDT).

  20. Non-Contact Laser Based Ultrasound Evaluation of Canned Foods

    NASA Astrophysics Data System (ADS)

    Shelton, David

    2005-03-01

    Laser-Based Ultrasound detection was used to measure the velocity of compression waves transmitted through canned foods. Condensed broth, canned pasta, and non-condensed soup were evaluated in these experiments. Homodyne adaptive optics resulted in measurements that were more accurate than the traditional heterodyne method, as well as yielding a 10 dB gain in signal to noise. A-Scans measured the velocity of ultrasound sent through the center of the can and were able to distinguish the quantity of food stuff in its path, as well as distinguish between meat and potato. B-Scans investigated the heterogeneity of the sample’s contents. The evaluation of canned foods was completely non-contact and would be suitable for continuous monitoring in production. These results were verified by conducting the same experiments with a contact piezo transducer. Although the contact method yields a higher signal to noise ratio than the non-contact method, Laser-Based Ultrasound was able to detect surface waves the contact transducer could not.

  1. Non-contact optical three dimensional liner metrology.

    SciTech Connect

    Sebring, R. J.; Anderson, W. E.; Bartos, J. J.; Garcia, F.; Randolph, B.; Salazar, M. A.; Edwards, J. M.

    2001-01-01

    We optically captured the 'as-built' liner geometry of NTLX (near term liner experiments) for Shiva Star using ultra-precision ranging lasers. We subsequently verified the resulting digitized geometry against the 3D CAD model of the part. The results confirmed that the Liner contours are within designed tolerances but revealed subtle fabrication artifacts that would typically go undetected. These features included centimeters long waviness and saddle and bulge regions of 1 micron or less in magnitude. The laser technology typically provided 10 micron spatial resolution with {+-}12 nanometer ranging precision. Atlas liners in the future may have to be diamond turned and will have the centimeter wavelength and 100 angstrom amplitude requirements. The advantages of using laser technology are (1) it avoids surface damage that may occur with conventional contact probes and (2) dramatically improves spatial resolution over CMM, capacitance and inductance type probes. Our work is the result of a perceived future need to develop precision, non-contact, liner inspection techniques to verify geometry, characterize machining artifacts and map wall thickness on delicate diamond turned surfaces. Capturing 'as-built' geometry in a non-contact way coupled with part-to-CAD verification software tools creates a new metrology competency for MST-7.

  2. A non-contact fiber Bragg grating vibration sensor.

    PubMed

    Li, Tianliang; Tan, Yuegang; Wei, Li; Zhou, Zude; Zheng, Kai; Guo, Yongxing

    2014-01-01

    A non-contact vibration sensor based on fiber Bragg grating (FBG) sensing has been proposed and studied in this paper. The principle of the sensor as well as simulation and experimental analyses are introduced. When the distance between the movable head and the measured shaft changed, the diaphragm deformed under magnetic coupling of the permanent magnet on the measured magnetic shaft. As a result, the center wavelength of the FBG connected to the diaphragm changed, based on which the vibration displacement of the rotating shaft could be obtained. Experimental results show that the resonant frequency of the sensor is about 1500 Hz and the working band ranges within 0-1300 Hz, which is consistent with the simulation analysis result; the sensitivity is -1.694 pm/μm and the linearity is 2.92% within a range of 2-2.4 mm. It can be used to conduct non-contact measurement on the vibration of the rotating shaft system.

  3. Non-Contact Conductivity Measurement for Automated Sample Processing Systems

    NASA Technical Reports Server (NTRS)

    Beegle, Luther W.; Kirby, James P.

    2012-01-01

    A new method has been developed for monitoring and control of automated sample processing and preparation especially focusing on desalting of samples before analytical analysis (described in more detail in Automated Desalting Apparatus, (NPO-45428), NASA Tech Briefs, Vol. 34, No. 8 (August 2010), page 44). The use of non-contact conductivity probes, one at the inlet and one at the outlet of the solid phase sample preparation media, allows monitoring of the process, and acts as a trigger for the start of the next step in the sequence (see figure). At each step of the muti-step process, the system is flushed with low-conductivity water, which sets the system back to an overall low-conductivity state. This measurement then triggers the next stage of sample processing protocols, and greatly minimizes use of consumables. In the case of amino acid sample preparation for desalting, the conductivity measurement will define three key conditions for the sample preparation process. First, when the system is neutralized (low conductivity, by washing with excess de-ionized water); second, when the system is acidified, by washing with a strong acid (high conductivity); and third, when the system is at a basic condition of high pH (high conductivity). Taken together, this non-contact conductivity measurement for monitoring sample preparation will not only facilitate automation of the sample preparation and processing, but will also act as a way to optimize the operational time and use of consumables

  4. Characterization of noncontact piezoelectric transducer with conically shaped piezoelement

    NASA Technical Reports Server (NTRS)

    Williams, James H., Jr.; Ochi, Simeon C. U.

    1988-01-01

    The characterization of a dynamic surface displacement transducer (IQI Model 501) by a noncontact method is presented. The transducer is designed for ultrasonic as well as acoustic emission measurements and, according to the manufacturer, its characteristic features include a flat frequency response range which is from 50 to 1000 kHz and a quality factor Q of less than unity. The characterization is based on the behavior of the transducer as a receiver and involves exciting the transducer directly by transient pulse input stress signals of quasi-electrostatic origin and observing its response in a digital storage oscilloscope. Theoretical models for studying the response of the transducer to pulse input stress signals and for generating pulse stress signals are presented. The characteristic features of the transducer which include the central frequency f sub o, quality factor Q, and flat frequency response range are obtained by this noncontact characterization technique and they compare favorably with those obtained by a tone burst method which are also presented.

  5. Damage visualization using synchronized noncontact laser ultrasonic scanning

    NASA Astrophysics Data System (ADS)

    Liu, Peipei; Sunarsa, Timotius Yonathan; Sohn, Hoon

    2016-04-01

    This paper presents a damage visualization technique using a fully noncontact laser ultrasonic measurement system and a synchronized scanning strategy. The noncontact laser ultrasonic measurement system is composed of a Q-switched Nd:YAG laser for ultrasonic wave generation and a laser Doppler vibrometer (LDV) for ultrasonic wave detection. The laser beams for ultrasonic wave generation and detection are shot on the target structure with a constant and tiny distance, and these two laser beams are synchronously moved over the scanning area. Compared with conventional laser scanning strategies, the ultrasonic responses detected through the synchronized scanning strategy owns a much higher and more stable signal to noise ratio and the scanning time can be significantly reduced with less time averaging. By spatial comparison in the scanning area, damage can be detected and visualized without relying on baseline data obtained from the pristine condition of the target structure. In this paper, the developed technique is validated by visualization hidden corrosion in a steel straight pipe and a steel elbow pipe.

  6. Dry-contact and noncontact biopotential electrodes: methodological review.

    PubMed

    Chi, Yu Mike; Jung, Tzyy-Ping; Cauwenberghs, Gert

    2010-01-01

    Recent demand and interest in wireless, mobile-based healthcare has driven significant interest towards developing alternative biopotential electrodes for patient physiological monitoring. The conventional wet adhesive Ag/AgCl electrodes used almost universally in clinical applications today provide an excellent signal but are cumbersome and irritating for mobile use. While electrodes that operate without gels, adhesives and even skin contact have been known for many decades, they have yet to achieve any acceptance for medical use. In addition, detailed knowledge and comparisons between different electrodes are not well known in the literature. In this paper, we explore the use of dry/noncontact electrodes for clinical use by first explaining the electrical models for dry, insulated and noncontact electrodes and show the performance limits, along with measured data. The theory and data show that the common practice of minimizing electrode resistance may not always be necessary and actually lead to increased noise depending on coupling capacitance. Theoretical analysis is followed by an extensive review of the latest dry electrode developments in the literature. The paper concludes with highlighting some of the novel systems that dry electrode technology has enabled for cardiac and neural monitoring followed by a discussion of the current challenges and a roadmap going forward.

  7. The control of neural cell-to-cell interactions through non-contact electrical field stimulation using graphene electrodes.

    PubMed

    Heo, Chaejeong; Yoo, Jeongwan; Lee, Siyoung; Jo, Areum; Jung, Susie; Yoo, Hyosun; Lee, Young Hee; Suh, Minah

    2011-01-01

    Electric field stimulation has become one of the most promising therapies for a variety of neurological diseases. However, the safety and effectiveness of the stimulator are critical in determining the outcome. Because there are few safe and effective in vivo and/or in vitro stimulator devices, we demonstrate a method that allows for non-contact electric field stimulation with a specific strength that is able to control cell-to-cell interaction in vitro. Graphene, a form of graphite, and polyethylene terephthalate (PET) was used to create a non-cytotoxic in vitro graphene/PET film stimulator. A transient non-contact electric field was produced by charge-balanced biphasic stimuli through the graphene/PET film electrodes and applied to cultured neural cells. We found that weak electric field stimulation (pulse duration of 10 s) as low as 4.5 mV/mm for 32 min was particularly effective in shaping cell-to-cell interaction. Under weak electric field stimulation, we observed a significant increase in the number of cells forming new cell-to-cell couplings and in the number of cells strengthening existing cell-to-cell couplings. The underlying mechanism of the altered cellular interactions may be related to an altered regulation of the endogenous cytoskeletal proteins fibronectin, actin, and vinculin. In conclusion, this technique may open a new therapeutic approach for augmenting cell-to-cell coupling in cell transplantation therapy in the central nervous system.

  8. A remote and non-contact method for obtaining the blood-pulse waveform with a laser Doppler vibrometer

    NASA Astrophysics Data System (ADS)

    Desjardins, Candida L.; Antonelli, Lynn T.; Soares, Edward

    2007-02-01

    The use of lasers to remotely and non-invasively detect the blood pressure waveform of humans and animals would provide a powerful diagnostic tool. Current blood pressure measurement tools, such as a cuff, are not useful for burn and trauma victims, and animals require catheterization to acquire accurate blood pressure information. The purpose of our sensor method and apparatus invention is to remotely and non-invasively detect the blood pulse waveform of both animals and humans. This device is used to monitor an animal or human's skin in proximity to an artery using radiation from a laser Doppler vibrometer (LDV). This system measures the velocity (or displacement) of the pulsatile motion of the skin, indicative of physiological parameters of the arterial motion in relation to the cardiac cycle. Tests have been conducted that measures surface velocity with an LDV and a signal-processing unit, with enhanced detection obtained with optional hardware including a retro-reflector dot. The blood pulse waveform is obtained by integrating the velocity signal to get surface displacement using standard signal processing techniques. Continuous recording of the blood pulse waveform yields data containing information on cardiac health and can be analyzed to identify important events in the cardiac cycle, such as heart rate, the timing of peak systole, left ventricular ejection time and aortic valve closure. Experimental results are provided that demonstrates the current capabilities of the optical, non-contact sensor for the continuous, non-contact recording of the blood pulse waveform without causing patient distress.

  9. A non-contact capacitance based electrocardiograph and associated heart-rate detection using enhanced Fourier interpolation method.

    PubMed

    Kumar Thakur, Rupak; Anoop, C S

    2015-08-01

    Cardio-vascular health monitoring has gained considerable attention in the recent years. Principle of non-contact capacitive electrocardiograph (ECG) and its applicability as a valuable, low-cost, easy-to-use scheme for cardio-vascular health monitoring has been demonstrated in some recent research papers. In this paper, we develop a complete non-contact ECG system using a suitable front-end electronic circuit and a heart-rate (HR) measurement unit using enhanced Fourier interpolation technique. The front-end electronic circuit is realized using low-cost, readily available components and the proposed HR measurement unit is designed to achieve fairly accurate results. The entire system has been extensively tested to verify its efficacy and test results show that the developed system can estimate HR with an accuracy of ±2 beats. Detailed tests have been conducted to validate the performance of the system for different cloth thicknesses of the subject. Some basic tests which illustrate the application of the proposed system for heart-rate variability estimation has been conducted and results reported. The developed system can be used as a portable, reliable, long-term cardiac health monitoring device and can be extended to human drowsiness detection.

  10. Non-contact continuous-wave diffuse optical tomographic system to capture vascular dynamics in the foot

    NASA Astrophysics Data System (ADS)

    Hoi, Jennifer W.; Kim, Hyun K.; Khalil, Michael A.; Fong, Christopher J.; Marone, Alessandro; Shrikhande, Gautam; Hielscher, Andreas H.

    2015-03-01

    Dynamic optical tomographic imaging has shown promise in diagnosing and monitoring peripheral arterial disease (PAD), which affects 8 to 12 million in the United States. PAD is the narrowing of the arteries that supply blood to the lower extremities. Prolonged reduced blood flow to the foot leads to ulcers and gangrene, which makes placement of optical fibers for contact-based optical tomography systems difficult and cumbersome. Since many diabetic PAD patients have foot wounds, a non-contact interface is highly desirable. We present a novel non-contact dynamic continuous-wave optical tomographic imaging system that images the vasculature in the foot for evaluating PAD. The system images at up to 1Hz by delivering 2 wavelengths of light to the top of the foot at up to 20 source positions through collimated source fibers. Transmitted light is collected with an electron multiplying charge couple device (EMCCD) camera. We demonstrate that the system can resolve absorbers at various locations in a phantom study and show the system's first clinical 3D images of total hemoglobin changes in the foot during venous occlusion at the thigh. Our initial results indicate that this system is effective in capturing the vascular dynamics within the foot and can be used to diagnose and monitor treatment of PAD in diabetic patients.

  11. Electromechanical modeling of a honeycomb core integrated vibration energy converter with increased specific power for energy harvesting applications

    NASA Astrophysics Data System (ADS)

    Chandrasekharan, Nataraj

    Innovation in integrated circuit technology along with improved manufacturing processes has resulted in considerable reduction in power consumption of electromechanical devices. Majority of these devices are currently powered by batteries. However, the issues posed by batteries, including the need for frequent battery recharge/replacement has resulted in a compelling need for alternate energy to achieve self-sufficient device operation or to supplement battery power. Vibration based energy harvesting methods through piezoelectric transduction provides with a promising potential towards replacing or supplementing battery power source. However, current piezoelectric energy harvesters generate low specific power (power-to-weight ratio) when compared to batteries that the harvesters seek to replace or supplement. In this study, the potential of integrating lightweight cellular honeycomb structures with existing piezoelectric device configurations (bimorph) to achieve higher specific power is investigated. It is shown in this study that at low excitation frequency ranges, replacing the solid continuous substrate of a conventional piezoelectric bimorph with honeycomb structures of the same material results in a significant increase in power-to-weight ratio of the piezoelectric harvester. In order to maximize the electrical response of vibration based power harvesters, the natural frequency of these harvesters is designed to match the input driving frequency. The commonly used technique of adding a tip mass is employed to lower the natural frequency (to match driving frequency) of both, solid and honeycomb substrate bimorphs. At higher excitation frequency, the natural frequency of the traditional solid substrate bimorph can only be altered (to match driving frequency) through a change in global geometric design parameters, typically achieved by increasing the thickness of the harvester. As a result, the size of the harvester is increased and can be disadvantageous

  12. Electromechanical Imaging of Biomaterials by Scanning Probe Microscopy

    SciTech Connect

    Rodriguez, Brian J; Kalinin, Sergei V; Shin, Junsoo; Jesse, Stephen; Grichko, V.; Thundat, Thomas George; Baddorf, Arthur P; Gruverman, A.

    2006-01-01

    The majority of calcified and connective tissues possess complex hierarchical structure spanning the length scales from nanometers to millimeters. Understanding the biological functionality of these materials requires reliable methods for structural imaging on the nanoscale. Here, we demonstrate an approach for electromechanical imaging of the structure of biological samples on the length scales from tens of microns to nanometers using piezoresponse force microscopy (PFM), which utilizes the intrinsic piezoelectricity of biopolymers such as proteins and polysaccharides as the basis for high-resolution imaging. Nanostructural imaging of a variety of protein-based materials, including tooth, antler, and cartilage, is demonstrated. Visualization of protein fibrils with sub-10 nm spatial resolution in a human tooth is achieved. Given the near-ubiquitous presence of piezoelectricity in biological systems, PFM is suggested as a versatile tool for micro- and nanostructural imaging in both connective and calcified tissues.

  13. Differentiating Ferroelectric and Nonferroelectric Electromechanical Effects with Scanning Probe Microscopy.

    PubMed

    Balke, Nina; Maksymovych, Petro; Jesse, Stephen; Herklotz, Andreas; Tselev, Alexander; Eom, Chang-Beom; Kravchenko, Ivan I; Yu, Pu; Kalinin, Sergei V

    2015-06-23

    Ferroelectricity in functional materials remains one of the most fascinating areas of modern science in the past several decades. In the last several years, the rapid development of piezoresponse force microscopy (PFM) and spectroscopy revealed the presence of electromechanical hysteresis loops and bias-induced remnant polar states in a broad variety of materials including many inorganic oxides, polymers, and biosystems. In many cases, this behavior was interpreted as the ample evidence for ferroelectric nature of the system. Here, we systematically analyze PFM responses on ferroelectric and nonferroelectric materials and demonstrate that mechanisms unrelated to ferroelectricity can induce ferroelectric-like characteristics through charge injection and electrostatic forces on the tip. We will focus on similarities and differences in various PFM measurement characteristics to provide an experimental guideline to differentiate between ferroelectric material properties and charge injection. In the end, we apply the developed measurement protocols to an unknown ferroelectric material.

  14. Evaluation of the electromechanical properties of the cardiovascular system

    NASA Technical Reports Server (NTRS)

    Bergman, S. A., Jr.; Hoffler, G. W.; Johnson, R. L.

    1974-01-01

    Cardiovascular electromechanical measurements were collected on returning Skylab crewmembers at rest and during both lower body negative pressure and exercise stress testing. These data were compared with averaged responses from multiple preflight tests. Systolic time intervals and first heart sound amplitude changes were measured. Clinical cardiovascular examinations and clinical phonocardiograms were evaluated. All changes noted returned to normal within 30 days postflight so that the processes appear to be transient and self limited. The cardiovascular system seems to adapt quite readily to zero-g, and more importantly it is capable of readaptation to one-g after long duration space flight. Repeated exposures to zero-g also appear to have no detrimental effects on the cardiovascular system.

  15. Mass sensing based on a circuit cavity electromechanical system

    NASA Astrophysics Data System (ADS)

    Jiang, Cheng; Chen, Bin; Li, Jin-Jin; Zhu, Ka-Di

    2011-10-01

    We present a scheme for mass sensing based on a circuit cavity electromechanical system where a free-standing, flexible aluminium membrane is capacitively coupled to a superconducting microwave cavity. Integration with the microwave cavity enables capacitive readout of the mechanical resonance directly on the chip. A microwave pump field and a second probe field are simultaneously applied to the cavity. The accreted mass landing on the membrane can be measured conveniently by tracking the mechanical resonance frequency shifts due to mass changes in the probe transmission spectrum. The mass responsivity for the membrane is 0.72 Hz/ag and we demonstrate that frequency shifts induced by adsorption of one hundred 1587 bp DNA molecules can be well resolved in the probe transmission spectrum.

  16. Electromechanical Behavior of Carbon Nanotubes-Conducting Polymer Films

    NASA Astrophysics Data System (ADS)

    Kim, Cheol; Liu, Xinyun

    A relationship between strain and applied potential is derived for composite films consisting of single-wall carbon nanotubes (SWNTs) and conductive polymers (CPs). When it is derived, an electrochemical ionic approach is utilized to formulate the electromechanical actuation of the film actuator. This relationship can give us a direct understanding of actuation of the nanoactuator. The results show that the well-aligned SWNTs composite actuator can give good actuation responses and high actuating forces available. The actuation is found to be affected by both SWNTs and CPs components and the actuation of SWNTs component has two kinds of influences on that of the CPs component: reinforcement at the positive voltage and abatement at the negative voltage. Optimizations of SWNTs-CPs composite actuator may be achieved by using well-aligned nanotubes as well as choosing suitable electrolyte and an input voltage range.

  17. Sub-kBT micro-electromechanical irreversible logic gate

    PubMed Central

    López-Suárez, M.; Neri, I.

    2016-01-01

    In modern computers, computation is performed by assembling together sets of logic gates. Popular gates like AND, OR and XOR, processing two logic inputs and yielding one logic output, are often addressed as irreversible logic gates, where the sole knowledge of the output logic value is not sufficient to infer the logic value of the two inputs. Such gates are usually believed to be bounded to dissipate a finite minimum amount of energy determined by the input–output information difference. Here we show that this is not necessarily the case, by presenting an experiment where a OR logic gate, realized with a micro-electromechanical cantilever, is operated with energy well below the expected limit, provided the operation is slow enough and frictional phenomena are properly addressed. PMID:27350333

  18. Sub-kBT micro-electromechanical irreversible logic gate.

    PubMed

    López-Suárez, M; Neri, I; Gammaitoni, L

    2016-01-01

    In modern computers, computation is performed by assembling together sets of logic gates. Popular gates like AND, OR and XOR, processing two logic inputs and yielding one logic output, are often addressed as irreversible logic gates, where the sole knowledge of the output logic value is not sufficient to infer the logic value of the two inputs. Such gates are usually believed to be bounded to dissipate a finite minimum amount of energy determined by the input-output information difference. Here we show that this is not necessarily the case, by presenting an experiment where a OR logic gate, realized with a micro-electromechanical cantilever, is operated with energy well below the expected limit, provided the operation is slow enough and frictional phenomena are properly addressed. PMID:27350333

  19. Compositional Effects on Electromechanical Degradation of RAINBOW Actuators

    NASA Technical Reports Server (NTRS)

    Dausch, David E.; Wise, Stephanie A.

    1998-01-01

    The effect of ceramic composition on the electromechanical displacement degradation of RAINBOW (Reduced and Internally Biased Oxide Wafer) actuators was investigated. RAINBOWs were fabricated from commercially available PZT-5H and PZT-5A piezoelectric disks as well as from tape cast PLZT piezoelectric 7/65/35 and electrostrictive 9/65/35 compositions. Displacement properties were measured at low electric fields (10 to 13 kV/cm) under loads of 0 to 500 g, and displacement degradation as a function of time was observed over 107 cycles. The PZT-5A and PLZT 9/65/35 compositions exhibited minimal decrease in displacement when load was applied. Furthermore, these compositions retained approximately 65 percent of their initial displacement after 10(exp 7) cycles under a load of 300 g. PZT-5H and PLZT 7/65/35 degraded completely under these conditions.

  20. Enhanced electromechanical response of ferroelectrics due to charged domain walls

    PubMed Central

    Sluka, Tomas; Tagantsev, Alexander K.; Damjanovic, Dragan; Gureev, Maxim; Setter, Nava

    2012-01-01

    While commonly used piezoelectric materials contain lead, non-hazardous, high-performance piezoelectrics are yet to be discovered. Charged domain walls in ferroelectrics are considered inactive with regards to the piezoelectric response and, therefore, are largely ignored in this search. Here we demonstrate a mechanism that leads to a strong enhancement of the dielectric and piezoelectric properties in ferroelectrics with increasing density of charged domain walls. We show that an incomplete compensation of bound polarization charge at these walls creates a stable built-in depolarizing field across each domain leading to increased electromechanical response. Our model clarifies a long-standing unexplained effect of domain wall density on macroscopic properties of domain-engineered ferroelectrics. We show that non-toxic ferroelectrics like BaTiO3 with dense patterns of charged domain walls are expected to have strongly enhanced piezoelectric properties, thus suggesting a new route to high-performance, lead-free ferroelectrics. PMID:22434191

  1. Design and application of electromechanical actuators for deep space missions

    NASA Technical Reports Server (NTRS)

    Haskew, Tim A.; Wander, John

    1994-01-01

    This progress report documents research and development efforts performed from August 16, 1993 through August 15, 1994 on NASA Grant NAG8-240, 'Design and Application of Electromechanical Actuators for Deep Space Missions.' Since the submission of our last progress report in February 1994, our efforts have been almost entirely focused on final construction of the test stand and experiment design. Hence, this report is dedicated solely to these topics. However, updates on our research personnel and our health monitoring and fault management efforts are provided in this summary. Following this executive summary are two report sections. The first is devoted to the motor drive being constructed for the test stand. The thrust of the next section is the mechanical and hydraulic design and construction based on the planned experimental requirements. Following both major sections are three appendices.

  2. Sub-kBT micro-electromechanical irreversible logic gate

    NASA Astrophysics Data System (ADS)

    López-Suárez, M.; Neri, I.; Gammaitoni, L.

    2016-06-01

    In modern computers, computation is performed by assembling together sets of logic gates. Popular gates like AND, OR and XOR, processing two logic inputs and yielding one logic output, are often addressed as irreversible logic gates, where the sole knowledge of the output logic value is not sufficient to infer the logic value of the two inputs. Such gates are usually believed to be bounded to dissipate a finite minimum amount of energy determined by the input-output information difference. Here we show that this is not necessarily the case, by presenting an experiment where a OR logic gate, realized with a micro-electromechanical cantilever, is operated with energy well below the expected limit, provided the operation is slow enough and frictional phenomena are properly addressed.

  3. Superconducting Cavity Electromechanics on a Silicon-on-Insulator Platform

    NASA Astrophysics Data System (ADS)

    Dieterle, Paul B.; Kalaee, Mahmoud; Fink, Johannes M.; Painter, Oskar

    2016-07-01

    Fabrication processes involving anhydrous hydrofluoric vapor etching are developed to create high-Q aluminum superconducting microwave resonators on free-standing silicon membranes formed from a silicon-on-insulator wafer. Using this fabrication process, a high-impedance 8.9-GHz coil resonator is coupled capacitively with a large participation ratio to a 9.7-MHz micromechanical resonator. Two-tone microwave spectroscopy and radiation pressure backaction are used to characterize the coupled system in a dilution refrigerator down to temperatures of Tf=11 mK , yielding a measured electromechanical vacuum coupling rate of g0/2 π =24.6 Hz and a mechanical resonator Q factor of Qm=1.7 ×1 07. Microwave backaction cooling of the mechanical resonator is also studied, with a minimum phonon occupancy of nm≈16 phonons being realized at an elevated fridge temperature of Tf=211 mK .

  4. Mortality in workers in electromechanical and electronics production

    SciTech Connect

    Park, R.; Silverstein, M.; Maizlish, N.; Robins, T.; Mirer, F.

    1986-07-16

    Concern expressed by a local union over excess cancer deaths at an electronics and electromechanical manufacturing facility for aircraft and missile applications prompted this mortality study. Chemical exposures included halogenated solvents, cutting fluids, solder fluxes, epoxy resins, cyanoacrylate resins, and acrylonitrile-based resins. From 1965 to 1979 there were 30 deaths from cancer among female workers; 15.5 was the expected number. From 1970 to 1979 there appeared to be significant excess proportions of deaths attributable to pancreatic cancer in men and women and of colon cancer, stomach cancer and ovarian cancer in women. From 1980 through 1983, there has been no evidence of increased cancer; however, the numbers are small. The authors recommend that an independent hygiene assessment be made of current production, paying strict attention to ventilation systems, resin handling systems, solvent use, and cutting fluid control in the grinding and maching operations. The establishment of a hazardous-materials control committee is recommended.

  5. Dynamic Electromechanical Characterization of Axially Poled PZT 95/5

    SciTech Connect

    Chhabildas, Lalit C.; Furnish, Michael D.; Montgomery, Stephen T.; Setchell, Robert E.

    1999-06-25

    We are conducting a comprehensive experimental study of the electromechanical behavior of poled PZT 95/5 (lead zirconate titattate). As part of this study, eight plane-wave tests have been conducted on axially poled PZT 95/5 at stress levels ranging from 0.9 to 4.6 GPa, using VISAR and electrical diagnos- tics. Observed wave velocities were slightly decreased from ultrasonic vahtes, by contrast' with unpoled samples. Compression waveforms show a step at 0.6 GPa more marked than for normally poled or unpoled samples; this may correspond to a poling effect on the ferroelectric/antiferroelectric transition. A similar step is observed on release. The released charge upon loading to 0.9 GPa is consistent with nearly complete depoling. Loading to higher stresses gave lower currents (factor of 10), suggesting shock-induced conduc- tivity or electrical breakdown.

  6. A RF superconducting electromechanical transducer for gravitational wave antennae

    NASA Astrophysics Data System (ADS)

    Bocko, Mark F.; Johnson, Warren W.; Iafolla, Valerio

    1989-03-01

    An electromechanical transducer based on a superconducting radio-frequency bridge circuit has been developed for use on a gravitational radiation detector. The low electrical loss of superconductors has made it possible to achieve electrical quality factors of several thousand in a lumped-element circuit which operates at 4 MHz. The bridge could be remotely balanced to one part in 50,000, which led to a displacement noise level of 10-15 m/sq rt Hz. It should be useful in measuring any physical quantity which can be made to change a capacitance. At the present stage of development, capacitance changes of 10-20 F could be detected in a 1-s integration time. One straightforward improvement, namely, the use of a low-phase-noise quartz crystal oscillator as the bridge excitation source, will reduce the noise to 10-17 m/sq rt Hz.

  7. Control of an electromechanical hydrocephalus shunt--a new approach.

    PubMed

    Elixmann, Inga M; Kwiecien, Monika; Goffin, Christine; Walter, Marian; Misgeld, Berno; Kiefer, Michael; Steudel, Wolf-Ingo; Radermacher, Klaus; Leonhardt, Steffen

    2014-09-01

    Hydrocephalus is characterized by an excessive accumulation of cerebrospinal fluid (CSF). Therapeutically, an artificial pressure relief valve (so-called shunt) is implanted which opens in case of increased intracranial pressure (ICP) and drains CSF into another body compartment. Today, available shunts are of a mechanical nature and drainage depends on the pressure drop across the shunt. According to the latest data, craniospinal compliance is considered to be even more important than mean ICP alone. In addition, ICP is not constant but varies due to several influences. In fact, heartbeat-related ICP waveform patterns depend on volume changes in the cranial vessels during a heartbeat and changes its shape as a function of craniospinal compliance. In this paper, we present an electromechanical shunt approach, which changes the CSF drainage as a function of the current ICP waveform. A series of 12 infusion tests in patients were analyzed and revealed a trend between the compliance and specific features of the ICP waveform. For waveform analysis of patient data, an existing signal processing algorithm was improved (using a Moore machine) and was implemented on a low-power microcontroller within the electromechanical shunt. In a test rig, the ICP waveforms were replicated and the decisions of the ICP analysis algorithm were verified. The proposed control algorithm consists of a cascaded integral controller which determines the target ICP from the measured waveform, and a faster inner-loop integral controller that keeps ICP close to the target pressure. Feedforward control using measurement data of the patient's position was implemented to compensate for changes in hydrostatic pressure during change in position. A model-based design procedure was used to lay out controller parameters in a simple model of the cerebrospinal system. Successful simulation results have been obtained with this new approach by keeping ICP within the target range for a healthy waveform.

  8. Electromechanical analysis of infarct border zone in chronic myocardial infarction

    PubMed Central

    Ashikaga, Hiroshi; Mickelsen, Steven R.; Ennis, Daniel B.; Rodriguez, Ignacio; Kellman, Peter; Wen, Han; McVeigh, Elliot R.

    2007-01-01

    To test the hypothesis that alterations in electrical activation sequence contribute to depressed systolic function in the infarct border zone, we examined the anatomic correlation of abnormal electromechanics and infarct geometry in the canine post-myocardial infarction (MI) heart, using a high-resolution MR-based cardiac electromechanical mapping technique. Three to eight weeks after an MI was created in six dogs, a 247-electrode epicardial sock was placed over the ventricular epicardium under thoracotomy. MI location and geometry were evaluated with delayed hyperenhancement MRI. Three-dimensional systolic strains in epicardial and endocardial layers were measured in five short-axis slices with motion-tracking MRI (displacement encoding with stimulated echoes). Epicardial electrical activation was determined from sock recordings immediately before and after the MR scans. The electrodes and MR images were spatially registered to create a total of 160 nodes per heart that contained mechanical, transmural infarct extent, and electrical data. The average depth of the infarct was 55% (SD 11), and the infarct covered 28% (SD 6) of the left ventricular mass. Significantly delayed activation (>mean + 2SD) was observed within the infarct zone. The strain map showed abnormal mechanics, including abnormal stretch and loss of the transmural gradient of radial, circumferential, and longitudinal strains, in the region extending far beyond the infarct zone. We conclude that the border zone is characterized by abnormal mechanics directly coupled with normal electrical depolarization. This indicates that impaired function in the border zone is not contributed by electrical factors but results from mechanical interaction between ischemic and normal myocardium. PMID:15908463

  9. Measurements of nanoresonator-qubit interactions in a hybrid quantum electromechanical system.

    PubMed

    Rouxinol, F; Hao, Y; Brito, F; Caldeira, A O; Irish, E K; LaHaye, M D

    2016-09-01

    Experiments to probe the basic quantum properties of motional degrees of freedom of mechanical systems have developed rapidly over the last decade. One promising approach is to use hybrid electromechanical systems incorporating superconducting qubits and microwave circuitry. However, a critical challenge facing the development of these systems is to achieve strong coupling between mechanics and qubits while simultaneously reducing coupling of both the qubit and mechanical mode to the environment. Here we report measurements of a qubit-coupled mechanical resonator system consisting of an ultra-high-frequency nanoresonator and a long coherence-time superconducting transmon qubit, embedded in a superconducting coplanar waveguide cavity. It is demonstrated that the nanoresonator and transmon have commensurate energies and transmon coherence times are one order of magnitude larger than for all previously reported qubit-coupled nanoresonators. Moreover, we show that numerical simulations of this new hybrid quantum system are in good agreement with spectroscopic measurements and suggest that the nanoresonator in our device resides at low thermal occupation number, near its ground state, acting as a dissipative bath seen by the qubit. We also outline how this system could soon be developed as a platform for implementing more advanced experiments with direct relevance to quantum information processing and quantum thermodynamics, including the study of nanoresonator quantum noise properties, reservoir engineering, and nanomechanical quantum state generation and detection. PMID:27483428

  10. Measurements of nanoresonator-qubit interactions in a hybrid quantum electromechanical system

    NASA Astrophysics Data System (ADS)

    Rouxinol, F.; Hao, Y.; Brito, F.; Caldeira, A. O.; Irish, E. K.; LaHaye, M. D.

    2016-09-01

    Experiments to probe the basic quantum properties of motional degrees of freedom of mechanical systems have developed rapidly over the last decade. One promising approach is to use hybrid electromechanical systems incorporating superconducting qubits and microwave circuitry. However, a critical challenge facing the development of these systems is to achieve strong coupling between mechanics and qubits while simultaneously reducing coupling of both the qubit and mechanical mode to the environment. Here we report measurements of a qubit-coupled mechanical resonator system consisting of an ultra-high-frequency nanoresonator and a long coherence-time superconducting transmon qubit, embedded in a superconducting coplanar waveguide cavity. It is demonstrated that the nanoresonator and transmon have commensurate energies and transmon coherence times are one order of magnitude larger than for all previously reported qubit-coupled nanoresonators. Moreover, we show that numerical simulations of this new hybrid quantum system are in good agreement with spectroscopic measurements and suggest that the nanoresonator in our device resides at low thermal occupation number, near its ground state, acting as a dissipative bath seen by the qubit. We also outline how this system could soon be developed as a platform for implementing more advanced experiments with direct relevance to quantum information processing and quantum thermodynamics, including the study of nanoresonator quantum noise properties, reservoir engineering, and nanomechanical quantum state generation and detection.

  11. Electro-Mechanical Testing of Conductive Materials Used in Flexible Electronics

    NASA Astrophysics Data System (ADS)

    Cordill, Megan; Glushko, Oleksandr; Putz, Barbara

    2016-02-01

    The use of flexible electronics has increased in recent years. In order to have robust and long lasting flexible displays and sensors, the combined electro-mechanical behavior needs to be assessed. The most common method to determine electrical and mechanical behavior of conductive thin films used in flexible electronics is the fragmentation test, or uniaxial tensile straining of the film and substrate. When performed in situ fracture and deformation behavior can be determined. The use of in situ electrical resistance measurements can be informative about the crack onset strain of brittle layers, such as transparent conductors, or the stretchability of metal interconnects. The combination of in situ electrical measurements with in situ X-ray or confocal laser scanning microscopy can provide even more information about the failure mechanisms of the material systems. Lattice strains and stresses can be measured with X-rays, while cracking and buckle delaminations can be studied with confocal laser scanning microscopy. These new combinations of in situ methods will be discussed as well as methods to quantify interfacial properties of conductive thin films on polymer substrates. The combined techniques provide valuable correlated electrical and mechanical data needed to understand failure mechanisms in flexible devices.

  12. Micro electro-mechanical system piezoelectric cantilever array for a broadband vibration energy harvester.

    PubMed

    Chun, Inwoo; Lee, Hyun-Woo; Kwon, Kwang-Ho

    2014-12-01

    Limited energy sources of ubiquitous sensor networks (USNs) such as fuel cells and batteries have grave drawbacks such as the need for replacements and re-charging owing to their short durability and environmental pollution. Energy harvesting which is converting environmental mechanical vibration into electrical energy has been researched with some piezoelectric materials and various cantilever designs to increase the efficiency of energy-harvesting devices. In this study, we focused on an energy-harvesting cantilever with a broadband vibration frequency. We fabricated a lead zirconate titanate (PZT) cantilever array with various Si proof masses on small beams (5.5 mm x 0.5 mm x 0.5 mm). We obtained broadband resonant frequencies ranging between 127 Hz and 136 Hz using a micro electro-mechanical system (MEMS) process. In order to obtain broadband resonant characteristics, the cantilever array was comprised of six cantilevers with different resonant frequencies. We obtained an output power of about 2.461 μW at an acceleration of 0.23 g and a resistance of 4 kΩ. The measured bandwidth of the resonant frequency was approximately 9 Hz (127-136 Hz), which is about six times wider than the bandwidth of a single cantilever. PMID:25971046

  13. Finite element modeling of the electromechanical coupling in ionic polymer transducers

    NASA Astrophysics Data System (ADS)

    Akle, Barbar; Habchi, Wassim; Wallmersperger, Thomas; Leo, Donald

    2010-04-01

    Several researchers are actively studying Ionomeric polymer transducers (IPT) as a large strain low voltage Electro- Active Polymer (EAP) actuator. EAPs are devices that do not contain any moving parts leading to a potential large life time. Furthermore, they are light weight and flexible. An IPT is made of an ion saturated polymer usually Nafion, sandwiched between two electrodes made of a mixture of Nafion and electrically conductive particles usually RuO2 or platinum. Nafion is an acid membrane in which the cations are mobile while the anions are covalently fixed to the polymer structure. Upon the application of an electric potential on the order of 2V at the electrodes the mobile positive ions migrate towards the cathode leading to bending strains in the order of 5%. Our earlier studies demonstrate that the cations develop thin boundary layers around the electrode. Later developments in this finite element model captured the importance of adding particles in the electrode. This study presents the electromechanical coupling in ionic polymer transducers. Since all our earlier models were restricted to the electro-chemical part, here we will introduce the chemomechanical coupling. This coupling is performed based on previous studies (Akle and Leo) in which the authors experimentally showed that the mechanical strain in IPTs is proportional to a linear term and a quadratic term of the charge accumulated at the electrode. The values of the linear and quadratic terms are extracted from experimental data.

  14. Micro electro-mechanical system piezoelectric cantilever array for a broadband vibration energy harvester.

    PubMed

    Chun, Inwoo; Lee, Hyun-Woo; Kwon, Kwang-Ho

    2014-12-01

    Limited energy sources of ubiquitous sensor networks (USNs) such as fuel cells and batteries have grave drawbacks such as the need for replacements and re-charging owing to their short durability and environmental pollution. Energy harvesting which is converting environmental mechanical vibration into electrical energy has been researched with some piezoelectric materials and various cantilever designs to increase the efficiency of energy-harvesting devices. In this study, we focused on an energy-harvesting cantilever with a broadband vibration frequency. We fabricated a lead zirconate titanate (PZT) cantilever array with various Si proof masses on small beams (5.5 mm x 0.5 mm x 0.5 mm). We obtained broadband resonant frequencies ranging between 127 Hz and 136 Hz using a micro electro-mechanical system (MEMS) process. In order to obtain broadband resonant characteristics, the cantilever array was comprised of six cantilevers with different resonant frequencies. We obtained an output power of about 2.461 μW at an acceleration of 0.23 g and a resistance of 4 kΩ. The measured bandwidth of the resonant frequency was approximately 9 Hz (127-136 Hz), which is about six times wider than the bandwidth of a single cantilever.

  15. Unraveling the origins of electromechanical response in mixed-phase Bismuth Ferrite

    SciTech Connect

    Vasudevan, Rama K; Okatan, M. B.; Liu, Y. Y.; Jesse, Stephen; Yang, J.-C.; Liang, W. -I.; Chu, Ying-Hao; Li, J. Y.; Kalinin, Sergei V; Valanoor, Nagarajan V

    2013-01-01

    The origin of giant electromechanical response in a mixed-phase rhombohedral-tetragonal BiFeO3 thin film is probed using sub-coercive scanning probe microscopy based multiple-harmonic measurements. Significant contributions to the strain arise from a second-order harmonic response localized at the phase boundaries. Strain and dissipation data, backed by thermodynamic calculations suggest that the source of the enhanced electromechanical response is the motion of phase boundaries. These findings elucidate the key role of labile phase boundaries, both natural and artificial, in achieving thin films with giant electromechanical properties.

  16. Intrinsic Predictive Factors of Noncontact Lateral Ankle Sprain in Collegiate Athletes

    PubMed Central

    Kobayashi, Takumi; Yoshida, Masahiro; Yoshida, Makoto; Gamada, Kazuyoshi

    2013-01-01

    Background: Lateral ankle sprain (LAS) is one of the most common injuries in sports. Despite extensive research, intrinsic factors that predict initial and recurrent noncontact LAS remain undefined. Purpose: To identify the predictive factors of initial and recurrent noncontact LAS, focusing on ankle flexibility and/or alignment in collegiate athletes. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 191 athletes were assessed during the preseason for factors predictive of noncontact LAS. The baseline measurements included weightbearing dorsiflexion range of motion (ROM), leg-heel angle, foot internal rotation angle in plantar flexion, classification according to the mortise test, and navicular–medial malleolus (NMM) distance. Occurrence of noncontact LAS and participation in practice and games were prospectively recorded for 11 months. Results: Of the 191 athletes assessed, 169 (145 males, 24 females) completed the study; 125 athletes had a history of ankle sprain. During the observational period, 16 athletes suffered noncontact LAS (0.58 per 1000 athlete-exposures) consisting of 4 initial sprains and 12 recurrences. The hazard ratio estimated by a Cox regression analysis showed that athletes with an NMM distance ≥4.65 cm were 4.14 times more likely to suffer an initial noncontact LAS than were athletes with a shorter NMM distance (95% confidence interval, 1.12-14.30) and that athletes with a weightbearing dorsiflexion ROM >49.5° were 1.12 times as likely to suffer a recurrent noncontact LAS compared with athletes with a lower ROM (95% confidence interval, 1.05-1.20). Conclusion: NMM distance predicts initial noncontact LAS, and weightbearing dorsiflexion ROM predicts recurrent noncontact LAS. PMID:26535263

  17. Electromechanical coupling and design considerations in single-layer MoS2 suspended-channel transistors and resonators

    NASA Astrophysics Data System (ADS)

    Yang, Rui; Islam, Arnob; Feng, Philip X.-L.

    2015-11-01

    We report on the analysis of electromechanical coupling effects in suspended doubly-clamped single-layer MoS2 structures, and the designs of suspended-channel field-effect transistors (FETs) and vibrating-channel nanoelectromechanical resonators. In DC gating scenario, signal transduction processes including electrostatic actuation, deflection, straining on bandgap, mobility, carrier density and their intricate cross-interactions, have been analyzed considering strain-enhanced mobility (by up to 4 times), to determine the transfer characteristics. In AC gating scenario and resonant operations (using 100 MHz and 1 GHz devices as relevant targets), we demonstrate that the vibrating-channel MoS2 devices can offer enhanced signals (than the zero-bandgap graphene counterparts), thanks to the resonant straining effects on electron transport of the semiconducting channel. We also show dependence of signal intensity and signal-to-background ratio (SBR) on device geometries and scaling effects, with SBR enhancement by a factor of ~8 for resonance signal, which provide guidelines toward designing future devices with desirable parameters.

  18. FY-93 noncontacting acoustic ultrasonic signature analysis development

    SciTech Connect

    Tow, D.M.; Rodriguez, J.G.; Williamson, R.L.; Blackwood, L.G.

    1994-04-01

    A noncontacting, long-standoff inspection system with proven capabilities in container fill identification has been under development at the Idaho National Engineering Laboratory. The system detects subtle change in container vibration characteristics caused by differences in the physical properties of the fill materials. A container is inspected by acoustically inducting it to vibrate and sensing the vibrational response with a laser vibrometer. A standoff distance of several meters is feasible. In previous work the system proved to be a reliable means of distinguishing between munitions with a variety of chemical fills. During FY-93, the system was modified to improve performance and simplify operation. Other FY-93 accomplishments include progress in modeling the vibrational characteristics of containers and refinements to the statistical classification algorithms. Progress was also made in identifying other applications for this technology.

  19. Biomedical Monitoring By A Novel Noncontact Radio Frequency Technology Project

    NASA Technical Reports Server (NTRS)

    Oliva-Buisson, Yvette J. (Compiler)

    2014-01-01

    The area of Space Health and Medicine is one of the NASA's Space Technology Grand Challenges. Space is an extreme environment which is not conducive to human life. The extraterrestrial environment can result in the deconditioning of various human physiological systems and thus require easy to use physiological monitoring technologies in order to better monitor space crews for appropriate health management and successful space missions and space operations. Furthermore, the Space Technology Roadmap's Technology Area Breakdown Structure calls for improvements in research to support human health and performance (Technology Area 06). To address these needs, this project investigated a potential noncontact and noninvasive radio frequency-based technique of monitoring central hemodynamic function in human research subjects in response to orthostatic stress.

  20. Non-contact measurement of rotation angle with solo camera

    NASA Astrophysics Data System (ADS)

    Gan, Xiaochuan; Sun, Anbin; Ye, Xin; Ma, Liqun

    2015-02-01

    For the purpose to measure a rotation angle around the axis of an object, a non-contact rotation angle measurement method based on solo camera was promoted. The intrinsic parameters of camera were calibrated using chessboard on principle of plane calibration theory. The translation matrix and rotation matrix between the object coordinate and the camera coordinate were calculated according to the relationship between the corners' position on object and their coordinates on image. Then the rotation angle between the measured object and the camera could be resolved from the rotation matrix. A precise angle dividing table (PADT) was chosen as the reference to verify the angle measurement error of this method. Test results indicated that the rotation angle measurement error of this method did not exceed +/- 0.01 degree.

  1. Non-contact displacement estimation using Doppler radar.

    PubMed

    Gao, Xiaomeng; Singh, Aditya; Yavari, Ehsan; Lubecke, Victor; Boric-Lubecke, Olga

    2012-01-01

    Non-contact Doppler radar has been used extensively for detection of physiological motion. Most of the results published to date have been focused on estimation of the physiological rates, such as respiratory rate and heart rate, with CW and modulated waveforms in various settings. Accurate assessment of chest displacement may take this type of monitoring to the new level, by enabling the estimation of associated cardiopulmonary volumes, and possibly pulse pressure. To obtain absolute chest displacement with highest precision, full nonlinear phase demodulation of the quadrature radar outputs must be performed. The accuracy of this type of demodulation is limited by the drifting received RF power, varying dc offset, and channel quadrature imbalance. In this paper we demonstrate that if relatively large motion is used to calibrate the system, smaller motion displacement may be acquired with the accuracy on the order of 30 µm. PMID:23366212

  2. Non-contact displacement estimation using Doppler radar.

    PubMed

    Gao, Xiaomeng; Singh, Aditya; Yavari, Ehsan; Lubecke, Victor; Boric-Lubecke, Olga

    2012-01-01

    Non-contact Doppler radar has been used extensively for detection of physiological motion. Most of the results published to date have been focused on estimation of the physiological rates, such as respiratory rate and heart rate, with CW and modulated waveforms in various settings. Accurate assessment of chest displacement may take this type of monitoring to the new level, by enabling the estimation of associated cardiopulmonary volumes, and possibly pulse pressure. To obtain absolute chest displacement with highest precision, full nonlinear phase demodulation of the quadrature radar outputs must be performed. The accuracy of this type of demodulation is limited by the drifting received RF power, varying dc offset, and channel quadrature imbalance. In this paper we demonstrate that if relatively large motion is used to calibrate the system, smaller motion displacement may be acquired with the accuracy on the order of 30 µm.

  3. Non-contact feature detection using ultrasonic Lamb waves

    DOEpatents

    Sinha, Dipen N.

    2011-06-28

    Apparatus and method for non-contact ultrasonic detection of features on or within the walls of hollow pipes are described. An air-coupled, high-power ultrasonic transducer for generating guided waves in the pipe wall, and a high-sensitivity, air-coupled transducer for detecting these waves, are disposed at a distance apart and at chosen angle with respect to the surface of the pipe, either inside of or outside of the pipe. Measurements may be made in reflection or transmission modes depending on the relative position of the transducers and the pipe. Data are taken by sweeping the frequency of the incident ultrasonic waves, using a tracking narrow-band filter to reduce detected noise, and transforming the frequency domain data into the time domain using fast Fourier transformation, if required.

  4. Method of Noncontact Calibration of the Robotic Ultrasonic Tomograph

    NASA Astrophysics Data System (ADS)

    Borikov, V. N.; Galtseva, O. V.; Filippov, G. A.

    2016-01-01

    The method of calibration of robotic ultrasonic tomograph with the construction of the trajectory of movement of the robot-manipulator on the object of control by using 3D- scanner is described. This method can significantly accelerate the process of calibration of tomograph and prevent possible displacement of the object during calibration. The algorithm of transition from use of a contact method of calibration of the tomograph to noncontact calibration is offered. Experimental data of application of this algorithm show a positive result: the time of research of object considerably decreases. Results of researches prove the practical relevance of the presented work and high efficiency of application of robotic ultrasonic tomography for nondestructive testing of objects of different forms.

  5. Noncontact transportation in water using ultrasonic traveling waves.

    PubMed

    Nomura, Shinfuku; Matula, Thomas J; Satonobu, Jun; Crum, Lawrence A

    2007-03-01

    A noncontact transport experiment in water using ultrasonic traveling waves was investigated. Acrylic, aluminum, and brass discs were used as test objects. Traveling waves were generated using two ultrasonic transducers attached at the ends of a vibrating plate. One side was used as the wave-source side and the other side was used as the wave-receiving side. Acrylic plates cemented to the sides of the vibrating plate formed a tank to hold water. Object transportation was accomplished by adding a small amount of water to the vibrating structure. The transport velocity of floating objects in water is faster than for floating transport in air because of buoyancy. The transport velocity of an object depends on water height. The minimum value of the velocity occurs when the disc thickness is equal to the water height. The transport velocity increases as the height of water increases. For very shallow depths, the largest velocity is obtained when cavitation-induced streaming occurs.

  6. Proceedings of the Second Noncontact Temperature Measurement Workshop

    NASA Technical Reports Server (NTRS)

    Hale, Robert R. (Editor)

    1989-01-01

    The state of the art in noncontact temperature measurement (NCTM) technology was reviewed and the NCTM requirements of microgravity materials processing community identified. The workshop included technical presentations and discussions which ranged from research on advanced concepts for temperature measurement to laboratory research and development regarding measurement principles and state-of-the-art engineering practices for NCTM methodology in commercial and industrial applications. Technical presentations were made concerning: NCTM needs as perceived by several NASA centers, recent ground-based NCT, research and development of industry, NASA, academia, and selected national laboratories, work-in-progress communication, and technical issues of the implementation of temperature measurement in the space environment to facilitate future U.S. materials science investigations.

  7. Advances in Non-Contact Measurement of Creep Properties

    NASA Technical Reports Server (NTRS)

    Hyers, Robert; Canepari, Stacy; White, Erica Bischoff; Cretegny, Laurent; Rogers, jan

    2009-01-01

    As the required service temperatures for superalloys increases, so do the demands on testing for development of these alloys. Non-contact measurement of creep of refractory metals using electrostatic levitation has been demonstrated at temperatures up to 2300 C using samples of only 20-40 mg. These measurements load the spherical specimen by inertial forces due to rapid rotation. However, the first measurements relied on photon pressure to accelerate the samples to the high rotational rates of thousands of rotations per second, limiting the applicability to low stresses and high temperatures. Recent advances in this area extend this measurement to higher stresses and lower-temperatures through the use of an induction motor to drive the sample to such high rotational speeds. Preliminary results on new measurements on new materials will be presented.

  8. Note: Effective measurement of retained I(c) in evaluating electromechanical properties of high temperature superconductor tapes by the voltage tap clipping technique.

    PubMed

    Dedicatoria, Marlon J; Bautista, Zhierwinjay; Shin, Hyung-Seop; Sim, Kideok

    2015-08-01

    In this note, the effectiveness of voltage tap clipping technique was assessed in evaluating the electromechanical properties of high temperature superconductor (HTS) tapes in the aspect of practical device applications. In the four-probe transport I(c) measurement, instead of directly soldering the voltage lead wires onto the HTS samples, they were tapped to the sample by either just clipping or soldering them to the clips. This technique facilitated the simultaneous and repeated retained I(c) measurement test for multiple samples. Finally, the critical double bending diameter of HTS tapes and the electrical properties of jointed and striated coated conductor tapes could be easily determined.

  9. Noncontact, low-frequency ultrasound as an effective therapy against Pseudomonas aeruginosa-infected biofilm wounds.

    PubMed

    Seth, Akhil K; Nguyen, Khang T; Geringer, Matthew R; Hong, Seok J; Leung, Kai P; Mustoe, Thomas A; Galiano, Robert D

    2013-01-01

    Bacterial biofilms, a critical chronic wound mediator, remain difficult to treat. Energy-based devices may potentially improve healing, but with no evidence of efficacy against biofilms. This study evaluates noncontact, low-frequency ultrasound (NLFU) in the treatment of biofilm-infected wounds. Six-millimeter dermal punch wounds in rabbit ears were inoculated with 10(7) colony-forming units of Pseudomonas aeruginosa or left as sterile controls. A biofilm was established in vivo using our published model. NLFU treatment was carried out every other day or every day, with contralateral ear wounds acting as internal, untreated controls. Wounds were harvested for several quantitative endpoints and scanning electron microscopy to evaluate the biofilm structure. The P. aeruginosa biofilm consistently impaired wound epithelialization and granulation. NLFU, both every other day and every day, improved healing and reduced bacterial counts relative to untreated controls (p < 0.05). Scanning electron microscopy confirmed a qualitative decrease in bacteria after both treatments. NLFU also reduced inflammatory cytokine expression (p < 0.05). Our study suggests that NLFU is an effective therapy against P. aeruginosa wound biofilm. This represents the first in vivo evidence of energy-based modalities' impact on wound biofilm, setting the foundation for future mechanistic studies. Continued wound care technology research is essential to improving our understanding, and treatment, of biofilm-infected chronic wounds.

  10. The importance of illumination in a non-contact photoplethysmography imaging system for burn wound assessment

    NASA Astrophysics Data System (ADS)

    Mo, Weirong; Mohan, Rachit; Li, Weizhi; Zhang, Xu; Sellke, Eric W.; Fan, Wensheng; DiMaio, J. Michael; Thatcher, Jeffery E.

    2015-02-01

    We present a non-contact, reflective photoplethysmogram (PPG) imaging method and a prototype system for identifying the presence of dermal burn wounds during a burn debridement surgery. This system aims to provide assistance to clinicians and surgeons in the process of dermal wound management and wound triage decisions. We examined the system variables of illumination uniformity and intensity and present our findings. An LED array, a tungsten light source, and eventually high-power LED emitters were studied as illumination methods for our PPG imaging device. These three different illumination sources were tested in a controlled tissue phantom model and an animal burn model. We found that the low heat and even illumination pattern using high power LED emitters provided a substantial improvement to the collected PPG signal in our animal burn model. These improvements allow the PPG signal from different pixels to be comparable in both time-domain and frequency-domain, simplify the illumination subsystem complexity, and remove the necessity of using high dynamic range cameras. Through the burn model output comparison, such as the blood volume in animal burn data and controlled tissue phantom model, our optical improvements have led to more clinically applicable images to aid in burn assessment.

  11. Development of a noncontact diffuse optical spectroscopy probe for measuring tissue optical properties

    PubMed Central

    Bish, Sheldon F.; Rajaram, Narasimhan; Nichols, Brandon; Tunnell, James W.

    2011-01-01

    Optical reflectance probes are often used as tools to obtain optical spectra from superficial tissues and subsequently determine optical and physiological properties associated with early stage cancer. These probes, when placed directly on the tissue, are known to cause significant pressure-dependent changes in local optical properties. To address this, we fit the probe with an optical device that images the illumination and collection fibers onto the tissue surface, eliminating the influence of contact probe pressure on the sampling area. The noncontact probe addition addresses new optical conditions that may affect its performance such as tissue surface contour, and specular reflections by implementing an autofocusing mechanism and cross polarization. Extracted optical properties of tissue simulating phantoms yield errors of 3.46% in reduced scattering and 8.62% in absorbance. Autofocusing has extended the depth of field from 4 mm to throughout the 12 mm range of autofocus travel, while cross polarization has removed the incidence angle dependent specular reflection component from the collected signal. PMID:22191909

  12. Development of a noncontact diffuse optical spectroscopy probe for measuring tissue optical properties.

    PubMed

    Bish, Sheldon F; Rajaram, Narasimhan; Nichols, Brandon; Tunnell, James W

    2011-12-01

    Optical reflectance probes are often used as tools to obtain optical spectra from superficial tissues and subsequently determine optical and physiological properties associated with early stage cancer. These probes, when placed directly on the tissue, are known to cause significant pressure-dependent changes in local optical properties. To address this, we fit the probe with an optical device that images the illumination and collection fibers onto the tissue surface, eliminating the influence of contact probe pressure on the sampling area. The noncontact probe addition addresses new optical conditions that may affect its performance such as tissue surface contour, and specular reflections by implementing an autofocusing mechanism and cross polarization. Extracted optical properties of tissue simulating phantoms yield errors of 3.46% in reduced scattering and 8.62% in absorbance. Autofocusing has extended the depth of field from 4 mm to throughout the 12 mm range of autofocus travel, while cross polarization has removed the incidence angle dependent specular reflection component from the collected signal. PMID:22191909

  13. Noncontact depth-resolved micro-scale optical coherence elastography of the cornea

    PubMed Central

    Wang, Shang; Larin, Kirill V.

    2014-01-01

    High-resolution elastographic assessment of the cornea can greatly assist clinical diagnosis and treatment of various ocular diseases. Here, we report on the first noncontact depth-resolved micro-scale optical coherence elastography of the cornea achieved using shear wave imaging optical coherence tomography (SWI-OCT) combined with the spectral analysis of the corneal Lamb wave propagation. This imaging method relies on a focused air-puff device to load the cornea with highly-localized low-pressure short-duration air stream and applies phase-resolved OCT detection to capture the low-amplitude deformation with nano-scale sensitivity. The SWI-OCT system is used here to image the corneal Lamb wave propagation with the frame rate the same as the OCT A-line acquisition speed. Based on the spectral analysis of the corneal temporal deformation profiles, the phase velocity of the Lamb wave is obtained at different depths for the major frequency components, which shows the depthwise distribution of the corneal stiffness related to its structural features. Our pilot experiments on ex vivo rabbit eyes demonstrate the feasibility of this method in depth-resolved micro-scale elastography of the cornea. The assessment of the Lamb wave dispersion is also presented, suggesting the potential for the quantitative measurement of corneal viscoelasticity. PMID:25426312

  14. A non-contact optical technique for vehicle tracking along bounded trajectories

    NASA Astrophysics Data System (ADS)

    Giancola, S.; Giberti, H.; Sala, R.; Tarabini, M.; Cheli, F.; Garozzo, M.

    2015-11-01

    This paper presents a method for measuring the non-controlled trajectory of a cart along a bounded rectilinear path. The method uses non-contact measurement devices to identify the position of a movable laser scanner working in helical mode in order to reconstruct the 3D model of bridges. The main idea of the proposed method is to use vision systems in order to identify the coordinates of the laser scanner placed on the cart with respect to the global reference system. A fit-to-purpose vision system has been implemented: the system uses three CCD's cameras mounted on the cart to identify the relative rotations with respect to the environment. Two lasers pointers and a laser distance meter are fixed at the starting point of the trajectory and pointing in the direction of motion of the cart, creating three dots on a plane placed on the cart. One of the camera detects the cart displacements and rotations in the plane using a blob analysis procedure. The method described in this paper has a constant uncertainty and the measurement range only depends on the lasers power. The theoretical accuracy of the measurement system is close to 1 mm for the translation along the motion direction and around 0.5 mm along the other two directions. Orientations measurement have a theoretical accuracy of less than 0.1 °. The solution has been implemented for the 3D reconstruction of concrete bridge; preliminary experimental results are presented and discussed.

  15. Flight Technology Improvement. [spaceborne optical radiometric instruments, attitude control, and electromechanical and power subsystems

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Shortcomings in spaceborne instrumentation technology are analyzed and recommendations are given for corrections and technology development. The technologies discussed are optical radiometric instruments and calibration, attitude control and determination, and electromechanical and power subsystems.

  16. Electromechanical simulation and test of rotating systems with magnetic bearing or piezoelectric actuator active vibration control

    NASA Technical Reports Server (NTRS)

    Palazzolo, Alan B.; Tang, Punan; Kim, Chaesil; Manchala, Daniel; Barrett, Tim; Kascak, Albert F.; Brown, Gerald; Montague, Gerald; Dirusso, Eliseo; Klusman, Steve

    1994-01-01

    This paper contains a summary of the experience of the authors in the field of electromechanical modeling for rotating machinery - active vibration control. Piezoelectric and magnetic bearing actuator based control are discussed.

  17. Bi-stable frequency up-conversion piezoelectric energy harvester driven by non-contact magnetic repulsion

    NASA Astrophysics Data System (ADS)

    Tang, Q. C.; Yang, Y. L.; Li, Xinxin

    2011-12-01

    This paper presents miniaturized energy harvesters, where the frequency up-conversion technique is used to improve the bandwidth of vibration energy harvesters. The proposed and developed miniature piezoelectric energy harvester utilizes magnetic repulsion forces to achieve non-contact frequency up-conversion, thereby avoiding mechanical collision and wear for long-term working durability. A pair of piezoelectric resonant cantilevers is micro-fabricated to generate electric power. A simplified model involving linear oscillators and magnetic interaction is deployed to demonstrate the feasibility of the device design. A bench-top harvester has been fabricated and characterized, resulting in average power generation of over 10 µW within a broad frequency range of 10-22 Hz under 1g acceleration.

  18. Organic double layer element driven by triboelectric nanogenerator: Study of carrier behavior by non-contact optical method

    NASA Astrophysics Data System (ADS)

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2016-02-01

    By using optical electric-field-induced second-harmonic generation (EFISHG) technique, we studied carrier behavior caused by contact electrification (CE) in an organic double-layer element. This double-layer sample was half suspended in the open air, where one electrode (anode or cathode) was connected with a Cu foil for electrification while the other electrode was floated. Results showed two distinct carrier behaviors, depending on the (anode or cathode) connections to the Cu foil, and these carrier behaviors were analyzed based on the Maxwell-Wagner model. The double-layer sample works as a simple solar cell device. The photovoltaic effect and CE process have been proved to be two paralleled effects without strong interaction with each other, while photoconductivity changing in the sample can enhance the relaxation of CE induced charges. By probing the carrier behavior in this half-suspended device, the EFISHG technique has been demonstrated to be an effective non-contact method for clarifying the CE effect on related energy harvesting devices and electronics devices. Meanwhile, the related physical analysis in this letter is also useful for elucidating the fundamental characteristic of hybrid energy system based on solar cell and triboelectric nanogenerator.

  19. Bayesian inference of hidden corrosion in steel bridge connections: Non-contact and sparse contact approaches

    NASA Astrophysics Data System (ADS)

    Earls, C. J.

    2013-12-01

    This paper describes approaches for inferring the presence and nature of hidden corrosion occurring between connection plies in steel truss bridges. The proposed methods furnish, both non-contact and very sparse contact inspection modalities supporting this goal.

  20. Infrared temperature control system for a completely noncontact polymerase chain reaction in microfluidic chips.

    PubMed

    Roper, Michael G; Easley, Christopher J; Legendre, Lindsay A; Humphrey, Joseph A C; Landers, James P

    2007-02-15

    A completely noncontact temperature system is described for amplification of DNA via the polymerase chain reaction (PCR) in glass microfluidic chips. An infrared (IR)-sensitive pyrometer was calibrated against a thermocouple inserted into a 550-nL PCR chamber and used to monitor the temperature of the glass surface above the PCR chamber during heating and cooling induced by a tungsten lamp and convective air source, respectively. A time lag of less than 1 s was observed between maximum heating rates of the solution and surface, indicating that thermal equilibrium was attained rapidly. Moreover, the time lag was corroborated using a one-dimensional heat-transfer model, which provided insight into the characteristics of the device and environment that caused the time lag. This knowledge will, in turn, allow for future tailoring of the devices to specific applications. To alleviate the need for calibrating the pyrometer with a thermocouple, the on-chip calibration of pyrometer was accomplished by sensing the boiling of two solutions, water and an azeotrope, and comparing the pyrometer output voltage against the known boiling points of these solutions. The "boiling point calibration" was successful as indicated by the subsequent chip-based IR-PCR amplification of a 211-bp fragment of the B. anthracis genome in a chamber reduced beyond the dimensions of a thermocouple. To improve the heating rates, a parabolic gold mirror was positioned above the microfluidic chip, which expedited PCR amplification to 18.8 min for a 30-cycle, three-temperature protocol. PMID:17297927

  1. Fail safe controllable output improved version of the Electromechanical battery

    DOEpatents

    Post, Richard F.

    1999-01-01

    Mechanical means are provided to control the voltages induced in the windings of a generator/motor. In one embodiment, a lever is used to withdraw or insert the entire stator windings from the cavity where the rotating field exists. In another embodiment, voltage control and/or switching off of the output is achievable with a variable-coupling generator/motor. A stator is made up of two concentric layers of windings, with a larger number of turns on the inner layer of windings than the outer layer of windings. The windings are to be connected in series electrically, that is, their voltages add vectorially. The mechanical arrangement is such that one or both of the windings can be rotated with respect to the other winding about their common central axis. Another improved design for the stator assembly of electromechanical batteries provides knife switch contacts that are in electrical contact with the stator windings. The operation of this embodiment depends on the fact that an abnormally large torque will be exerted on the stator structure during any short-circuit condition.

  2. Electromechanical battery design suitable for back-up power applications

    DOEpatents

    Post, Richard F.

    2002-01-01

    The windings that couple energy into and out of the rotor of an electro-mechanical battery are modified. The normal stator windings of the generator/motor have been replaced by two orthogonal sets of windings. Because of their orthogonality, they are decoupled from each other electrically, though each can receive (or deliver) power flows from the rotating field produced by the array of permanent magnets. Due to the orthogonal design of the stator windings and the high mechanical inertia of the flywheel rotor, the resulting power delivered to the computer system is completely insensitive to any and all electrical transients and variabilities of the power from the main power source. This insensitivity includes complete failure for a period determined only by the amount of stored kinetic energy in the E-M battery modules that are supplied. Furthermore there is no need whatsoever for fast-acting, fractional-cycle switches, such as are employed in conventional systems, and which are complicated to implement.

  3. Multimode damage tracking and failure prognosis in electromechanical systems

    NASA Astrophysics Data System (ADS)

    Chelidze, David

    2002-07-01

    In this paper a modification to a general-purpose machinery diagnostic/prognostic algorithm that can handle two or more simultaneously occurring failure processes is described. The method is based on a theory that views damage as occurring in a hierarchical dynamical system where slowly evolving, hidden failure processes are causing nonstationarity in a fast, directly observable system. The damage variable tracking is based on statistics calculated using data-based local linear models constructed in the reconstructed phase space of the fast system. These statistics are designed to measure a local change in the fast systems flow caused by the slow-time failure processes. The method is applied to a mathematical model of an experimental electromechanical system consisting of a beam vibrating in a potential field crated by two electromagnets. Two failure modes are introduced through discharging batteries supplying power to these electromagnets. Open circuit terminal voltage of these batteries is a two-dimensional damage variable. Using computer simulations, it is demonstrated both analytically and experimentally that the proposed method can accurately track both damage variables using only a displacement measurements from the vibrating beam. The accurate estimates of remaining time to failure for each battery are given well ahead of actual breakdowns.

  4. High-speed electromechanical shutter for imaging spectrographs

    NASA Technical Reports Server (NTRS)

    Nguyen, Quang-Viet (Inventor)

    2005-01-01

    The present invention presents a high-speed electromechanical shutter which has at least two rotary beam choppers that are synchronized using a phase-locked loop electronic control to reduce the duty cycle. These choppers have blade means that can comprise discs or drums, each having about 60 (+/-15) slots which are from about 0.3 to about 0.8 mm wide and about 5 to about 20 mm long (radially) which are evenly distributed through out 360?, and a third rotary chopper which is optically aligned has a small number of slots, such as for example, 1 to 10 slots which are about 1 to about 2 mm wide and about 5 to about 20 mm long (radially). Further the blade means include phase slots that allow the blade means to be phase locked using a closed loop control circuit. In addition, in a preferred embodiment, the system also has a leaf shutter. Thus the invention preferably achieves a gate width of less than about 100 microseconds, using motors that operate at 3000 to 10,000 rpm, and with a phase jitter of less than about 1.5 microseconds, and further using an aperture with more than about 75% optical transmission with a clear aperture of about 0.8 mm?10 mm. The system can be synchronized to external sources at 0 6 kHz lasers, data acquisition systems, and cameras.

  5. Development of micro-electromechanical system (MEMS) cochlear biomodel

    NASA Astrophysics Data System (ADS)

    Ngelayang, Thailis Bounya Anak; Latif, Rhonira

    2015-05-01

    Human cochlear is undeniably one of the most amazing organs in human body. The functional mechanism is very unique in terms of its ability to convert the sound waves in the form of mechanical vibrations into the electrical nerve impulses. It is known that the normal human auditory system can perceive the audible frequency range between 20 Hz to 20 kHz. Scientists have conducted several researches trying to build the artificial basilar membrane in the human cochlea (cochlear biomodel). Micro-electromechanical system (MEMS) is one of the potential inventions that have the ability to mimic the active behavior of the basilar membrane. In this paper, an array of MEMS bridge beams that are mechanically sensitive to the perceived audible frequency has been proposed. An array of bridge bridge beams with 0.5 µm thickness and length varying from 200 µm to 2000 µm have been designed operate within the audible frequency range. In the bridge beams design, aluminium (Al), copper (Cu), tantalum (Ta) and platinum (Pt) have considered as the material for the bridge beam structure. From the finite element (FE) and lumped element (LE) models of the MEMS bridge beams, platinum has been found to be the best material for the cochlear biomodel design, closely mimicking the basilar membrane.

  6. Electro-Mechanical Actuator. DC Resonant Link Controller

    NASA Technical Reports Server (NTRS)

    Schreiner, Kenneth E.

    1996-01-01

    This report summarizes the work performed on the 68 HP electro-mechanical actuator (EMA) system developed on NASA contract for the Electrical Actuation (ELA) Technology Bridging Program. The system was designed to demonstrate the capability of large, high power linear ELAs for applications such as Thrust Vector Control (TVC) on rocket engines. It consists of a motor controller, drive electronics and a linear actuator capable of up to 32,00 lbs loading at 7.4 inches/second. The drive electronics are based on the Resonant DC link concept and operate at a nominal frequency of 55 kHz. The induction motor is a specially designed high speed, low inertia motor capable of a 68 peak HP. The actuator was originally designed by MOOG Aerospace under an internal R & D program to meet Space Shuttle Main Engine (SSME) TVC requirements. The design was modified to meet this programs linear rate specification of 7.4 inches/second. The motor and driver were tested on a dynamometer at the Martin Marietta Space Systems facility. System frequency response, step response and force-velocity tests were conducted at the MOOG Aerospace facility. A complete description of the system and all test results can be found in the body of the report.

  7. pH-dependent mechanisms of electromechanical cartilage reshaping

    NASA Astrophysics Data System (ADS)

    Wu, Edward C.; Manuel, Cyrus T.; Protsenko, Dmitriy E.; Karimi, Koohyar; Hamamoto, Ashley; Wong, Brian J. F.

    2011-03-01

    Electromechanical reshaping of cartilage is a novel modality that has significant clinical applications in otolaryngology and plastic surgery. Although EMR dosimetry has been extensively studied, little is known about the mechanisms of EMR, of which local tissue pH changes is believed to play a role. In this study, rabbit nasal septal cartilage is subject to a number of experiments aimed at elucidating pH-related changes using phenol red. The lateral extent and magnitude of pH change as well as factors that impact pH change are studied. Increasing voltage and application appear to increase the area and intensity of color change. With parameters known to produce thermal tissue injury, a transitional zone likely representing a confluence of acid-base products is noted in the region around the bend axis. Furthermore, rehydration and pH indicator application time do not appear to play a role in the quality of pH change. These simple experiments may provide insight into the role of pH changes in EMR that may allow correlation of dosimetry to tissue damage, further optimizing the clinical potential of EMR.

  8. Characterization of the electromechanical properties of EAP materials

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Sherrita, Stewart; Bhattachary, Kaushik; Lih, Shyh-Shiuh

    2001-01-01

    Electroactive polymers (EAP) are an emerging class of actuation materials. Their large electrically induced strains (longitudinal or bending), low density, mechanical flexibility, and ease of processing offer advantages over traditional electroactive materials. However, before the capability of these materials can be exploited, their electrical and mechanical behavior must be properly quantified. Two general types of EAP can be identified. The first type is ionic EAP, which requires relatively low voltages (<10V) to achieve large bending deflections. This class usually needs to be hydrated and electrochemical reactions may occur. The second type is Electronic-EAP and it involves electrostrictive and/or Maxwell stresses. This type of materials requires large electric fields (>100MV/m) to achieve longitudinal deformations at the range from 4 - 360%. Some of the difficulties in characterizing EAP include: nonlinear properties, large compliance (large mismatch with metal electrodes), nonhomogeneity resulting from processing, etc. To support the need for reliable data, the authors are developing characterization techniques to quantify the electroactive responses and material properties of EAP materials. The emphasis of the current study is on addressing electromechanical issues related to the ion-exchange type EAP also known as IPMC. The analysis, experiments and test results are discussed in this paper.

  9. VLT deformable secondary mirror: integration and electromechanical tests results

    NASA Astrophysics Data System (ADS)

    Biasi, R.; Andrighettoni, M.; Angerer, G.; Mair, C.; Pescoller, D.; Lazzarini, P.; Anaclerio, E.; Mantegazza, M.; Gallieni, D.; Vernet, E.; Arsenault, R.; Madec, P.-Y.; Duhoux, P.; Riccardi, A.; Xompero, M.; Briguglio, R.; Manetti, M.; Morandini, M.

    2012-07-01

    The VLT Deformable secondary is planned to be installed on the VLT UT#4 as part of the telescope conversion into the Adaptive Optics test Facility (AOF). The adaptive unit is based on the well proven contactless, voice coil motor technology that has been already successfully implemented in the MMT, LBT and Magellan adaptive secondaries, and is considered a promising technical choice for the forthcoming ELT-generation adaptive correctors, like the E-ELT M4 and the GMT ASM. The VLT adaptive unit has been recently assembled after the completion of the manufacturing and modular test phases. In this paper, we present the most relevant aspects of the system integration and report the preliminary results of the electromechanical tests performed on the unit. This test campaign is a typical major step foreseen in all similar systems built so far: thanks to the metrology embedded in the system, that allows generating time-dependent stimuli and recording in real time the position of the controlled mirror on all actuators, typical dynamic response quality parameters like modal settling time, overshoot and following error can be acquired without employing optical measurements. In this way the system dynamic and some aspect of its thermal and long term stability can be fully characterized before starting the optical tests and calibrations.

  10. Electromechanical role of fixed charge in the mammalian tectorial membrane

    NASA Astrophysics Data System (ADS)

    Ghaffari, Roozbeh; Page, Scott; Farrahi, Shirin; Sellon, Jonathan B.; Freeman, Dennis M.

    2015-12-01

    The mammalian tectorial membrane (TM) is thought to play a purely mechanical role in stimulating cochlear sensory receptors, but the presence of glycosaminoglycans and associated fixed charge groups suggests that electromechanical properties also may be important. Here, we measure the fixed charge concentration of the TM (-7.1 mmol/L at physiological pH), and show that this concentration of fixed charge is sufficient to generate electrokinetic motions of the TM. Electrically-evoked TM motions were nanometer-scaled (5-200 nm), increased linearly with electric field amplitude (0.05-20 kV/m) and decreased with frequency (1-1000 Hz). This frequency dependence can be understood in terms of the interplay between electrophoresis and electro-osmosis. Although the electric fields applied in this study were large, they are comparable in amplitude to the electric fields generated near hair cell transduction channels. TM electrokinetics could thus play a role in the deflection of cochlear hair bundles in vivo.

  11. High-speed electromechanical chutter for imaging spectrographs

    NASA Technical Reports Server (NTRS)

    Nguyen, Quang-Viet (Inventor)

    2005-01-01

    The present invention presents a high-speed electromechanical shutter which has at least two rotary beam choppers that are synchronized using a phase-locked loop electronic control to reduce the duty cycle. These choppers have blade means that can comprise discs or drums, each having about 60 (+/- 15) slots which are from about 0.3 to about 0.8 mm wide and about 5 to about 20 nun long (radially) which are evenly distributed through out 360 deg, and a third rotary chopper which is optically aligned has a small number of slots, such as for example, 1 to 10 slots which are about 1 to about 2 mm wide and about 5 to about 20 mm long (radially). Further the blade means include phase slots that allow the blade means to be phase locked using a closed loop control circuit. In addition, in a preferred embodiment, the system also has a leaf shutter. Thus the invention preferably achieves a gate width of less than about 100 microseconds, using motors that operate at 3000 to 10,OOO rpm, and with a phase jitter of less than about 1.5 microseconds, and further using an aperture with more than about 75% optical transmission with a clear aperture of about 0.8 -10 nun. The system can be synchronized to external sources at 0 6 kHz lasers, data acquisition systems, and cameras.

  12. Fail safe controllable output improved version of the electromechanical battery

    DOEpatents

    Post, R.F.

    1999-01-19

    Mechanical means are provided to control the voltages induced in the windings of a generator/motor. In one embodiment, a lever is used to withdraw or insert the entire stator windings from the cavity where the rotating field exists. In another embodiment, voltage control and/or switching off of the output is achievable with a variable-coupling generator/motor. A stator is made up of two concentric layers of windings, with a larger number of turns on the inner layer of windings than the outer layer of windings. The windings are to be connected in series electrically, that is, their voltages add vectorially. The mechanical arrangement is such that one or both of the windings can be rotated with respect to the other winding about their common central axis. Another improved design for the stator assembly of electromechanical batteries provides knife switch contacts that are in electrical contact with the stator windings. The operation of this embodiment depends on the fact that an abnormally large torque will be exerted on the stator structure during any short-circuit condition. 4 figs.

  13. Development of micro-electromechanical system (MEMS) cochlear biomodel

    SciTech Connect

    Ngelayang, Thailis Bounya Anak; Latif, Rhonira

    2015-05-15

    Human cochlear is undeniably one of the most amazing organs in human body. The functional mechanism is very unique in terms of its ability to convert the sound waves in the form of mechanical vibrations into the electrical nerve impulses. It is known that the normal human auditory system can perceive the audible frequency range between 20 Hz to 20 kHz. Scientists have conducted several researches trying to build the artificial basilar membrane in the human cochlea (cochlear biomodel). Micro-electromechanical system (MEMS) is one of the potential inventions that have the ability to mimic the active behavior of the basilar membrane. In this paper, an array of MEMS bridge beams that are mechanically sensitive to the perceived audible frequency has been proposed. An array of bridge bridge beams with 0.5 µm thickness and length varying from 200 µm to 2000 µm have been designed operate within the audible frequency range. In the bridge beams design, aluminium (Al), copper (Cu), tantalum (Ta) and platinum (Pt) have considered as the material for the bridge beam structure. From the finite element (FE) and lumped element (LE) models of the MEMS bridge beams, platinum has been found to be the best material for the cochlear biomodel design, closely mimicking the basilar membrane.

  14. Grinding process monitoring based on electromechanical impedance measurements

    NASA Astrophysics Data System (ADS)

    Marchi, Marcelo; Guimarães Baptista, Fabricio; de Aguiar, Paulo Roberto; Bianchi, Eduardo Carlos

    2015-04-01

    Grinding is considered one of the last processes in precision parts manufacturing, which makes it indispensable to have a reliable monitoring system to evaluate workpiece surface integrity. This paper proposes the use of the electromechanical impedance (EMI) method to monitor the surface grinding operation in real time, particularly the surface integrity of the ground workpiece. The EMI method stands out for its simplicity and for using low-cost components such as PZT (lead zirconate titanate) piezoelectric transducers. In order to assess the feasibility of applying the EMI method to the grinding process, experimental tests were performed on a surface grinder using a CBN grinding wheel and a SAE 1020 steel workpiece, with PZT transducers mounted on the workpiece and its holder. During the grinding process, the electrical impedance of the transducers was measured and damage indices conventionally used in the EMI method were calculated and compared with workpiece wear, indicating the surface condition of the workpiece. The experimental results indicate that the EMI method can be an efficient and cost-effective alternative for monitoring precision workpieces during the surface grinding process.

  15. Whole Heart Modeling: Applications to Cardiac Electrophysiology and Electromechanics

    PubMed Central

    Trayanova, Natalia A

    2010-01-01

    Rationale Recent developments in cardiac simulation have rendered the heart the most highly integrated example of a virtual organ. We are on the brink of a revolution in cardiac research–one in which computational modeling of proteins, cells, tissues and the organ allow to link genomic and proteomic information to the integrated organ behavior, in the quest to provide quantitative understanding of the functioning of the heart in health and disease. Objective The goal of this article is to assess the current state-of-the-art in whole-heart modeling and the plethora of its applications in cardiac research. Methods and Results General whole-heart modeling approaches are presented, and the applications of whole-heart models in cardiac electrophysiology and electromechanics research are reviewed. The article showcases the contributions that whole-heart modeling and simulation have made to our understanding of the functioning of the heart. A summary of the future developments envisioned for the field of cardiac simulation and modeling is also presented. Conclusions Biophysically-based computational modeling of the heart, applied to human heart physiology and the diagnosis and treatment of cardiac disease, has the potential to dramatically change twenty-first century cardiac research and the field of cardiology. PMID:21212393

  16. Multi-functional micro electromechanical devices and method of bulk manufacturing same

    NASA Technical Reports Server (NTRS)

    Okojie, Robert S. (Inventor)

    2004-01-01

    A method of bulk manufacturing SiC sensors is disclosed and claimed. Materials other than SiC may be used as the substrate material. Sensors requiring that the SiC substrate be pierced are also disclosed and claimed. A process flow reversal is employed whereby the metallization is applied first before the recesses are etched into or through the wafer. Aluminum is deposited on the entire planar surface of the metallization. Photoresist is spun onto the substantially planar surface of the Aluminum which is subsequently masked (and developed and removed). Unwanted Aluminum is etched with aqueous TMAH and subsequently the metallization is dry etched. Photoresist is spun onto the still substantially planar surface of Aluminum and oxide and then masked (and developed and removed) leaving the unimidized photoresist behind. Next, ITO is applied over the still substantially planar surface of Aluminum, oxide and unimidized photoresist. Unimidized and exposed photoresist and ITO directly above it are removed with Acetone. Next, deep reactive ion etching attacks exposed oxide not protected by ITO. Finally, hot phosphoric acid removes the Al and ITO enabling wires to connect with the metallization. The back side of the SiC wafer may be also be etched.

  17. Implantable centrifugal blood pump with dual impeller and double pivot bearing system: electromechanical actuator, prototyping, and anatomical studies.

    PubMed

    Bock, Eduardo; Antunes, Pedro; Leao, Tarcisio; Uebelhart, Beatriz; Fonseca, Jeison; Leme, Juliana; Utiyama, Bruno; da Silva, Cibele; Cavalheiro, Andre; Filho, Diolino Santos; Dinkhuysen, Jarbas; Biscegli, Jose; Andrade, Aron; Arruda, Celso

    2011-05-01

    An implantable centrifugal blood pump has been developed with original features for a left ventricular assist device. This pump is part of a multicenter and international study with the objective to offer simple, affordable, and reliable devices to developing countries. Previous computational fluid dynamics investigations and wear evaluation in bearing system were performed followed by prototyping and in vitro tests. In addition, previous blood tests for assessment of normalized index of hemolysis show results of 0.0054±2.46 × 10⁻³ mg/100 L. An electromechanical actuator was tested in order to define the best motor topology and controller configuration. Three different topologies of brushless direct current motor (BLDCM) were analyzed. An electronic driver was tested in different situations, and the BLDCM had its mechanical properties tested in a dynamometer. Prior to evaluation of performance during in vivo animal studies, anatomical studies were necessary to achieve the best configuration and cannulation for left ventricular assistance. The results were considered satisfactory, and the next step is to test the performance of the device in vivo.

  18. A novel closed-loop electromechanical stimulator to enhance osseointegration with immediate loading of dental implant restorations.

    PubMed

    Meswania, I M; Bousdras, V A; Ahir, S P; Cunningham, J L; Blunn, G W; Goodship, A E

    2010-10-01

    The degree of osseomechanical integration of dental implants is acutely sensitive to their mechanical environment. Bone, both as a tissue and structure, adapts its mass and architecture in response to loading conditions. Therefore, application of predefined controlled loads may be considered as a treatment option to promote early maturation of bone/implant interface prior to or in conjunction with crown/prosthesis attachment. Although many studies have established that the magnitude, rate of the applied strain, and frequency have significant effects on the osteogenic response, the actual specific relationships between strain parameters and frequency have not yet been fully defined. The purpose of this study was to develop a stimulator to apply defined mechanical stimuli to individual dental implants in vivo immediately after implantation, exploring the hypothesis that immediate controlled loading could enhance implant integration. An electromechanical device was developed, based on load values obtained using a two-dimensional finite element analysis of the bone/implant interface generating 1000 to 4000 pe and operated at 30 and 3 Hz respectively. The device was then tested in a cadaveric pig mandible, and periosteal bone surface strains were recorded for potential future comparison with a three-dimensional finite element model to determine loading regimens to optimize interface strains and iterate the device for clinical use.

  19. Electromechanical actuator with controllable motion, fast response rate, and high-frequency resonance based on graphene and polydiacetylene.

    PubMed

    Liang, Jiajie; Huang, Lu; Li, Na; Huang, Yi; Wu, Yingpeng; Fang, Shaoli; Oh, Jiyoung; Kozlov, Mikhail; Ma, Yanfeng; Li, Feifei; Baughman, Ray; Chen, Yongsheng

    2012-05-22

    Although widely investigated, novel electromechanical actuators with high overall actuation performance are still in urgent need for various practical and scientific applications, such as robots, prosthetic devices, sensor switches, and sonar projectors. In this work, combining the properties of unique environmental perturbations-actuated deformational isomerization of polydiacetylene (PDA) and the outstanding intrinsic features of graphene together for the first time, we design and fabricate an electromechanical bimorph actuator composed of a layer of PDA crystal and a layer of flexible graphene paper through a simple yet versatile solution approach. Under low applied direct current (dc), the graphene-PDA bimorph actuator with strong mechanical strength can generate large actuation motion (curvature is about 0.37 cm(-1) under a current density of 0.74 A/mm(2)) and produce high actuation stress (more than 160 MPa/g under an applied dc of only 0.29 A/mm(2)). When applying alternating current (ac), this actuator can display reversible swing behavior with long cycle life under high frequencies even up to 200 Hz; significantly, while the frequency and the value of applied ac and the state of the actuators reach an appropriate value, the graphene-PDA actuator can produce a strong resonance and the swing amplitude will jump to a peak value. Moreover, this stable graphene-PDA actuator also demonstrates rapidly and partially reversible electrochromatic phenomenon when applying an ac. Two mechanisms-the dominant one, electric-induced deformation, and a secondary one, thermal-induced expansion of PDA-are proposed to contribute to these interesting actuation performances of the graphene-PDA actuators. On the basis of these results, a mini-robot with controllable direction of motion based on the graphene-PDA actuator is designed to illustrate the great potential of our discoveries for practical use. Combining the unique actuation mechanism and many outstanding properties of

  20. Personalized biomedical devices & systems for healthcare applications

    NASA Astrophysics Data System (ADS)

    Chen, I.-Ming; Phee, Soo Jay; Luo, Zhiqiang; Lim, Chee Kian

    2011-03-01

    With the advancement in micro- and nanotechnology, electromechanical components and systems are getting smaller and smaller and gradually can be applied to the human as portable, mobile and even wearable devices. Healthcare industry have started to benefit from this technology trend by providing more and more miniature biomedical devices for personalized medical treatments in order to obtain better and more accurate outcome. This article introduces some recent development in non-intrusive and intrusive biomedical devices resulted from the advancement of niche miniature sensors and actuators, namely, wearable biomedical sensors, wearable haptic devices, and ingestible medical capsules. The development of these devices requires carful integration of knowledge and people from many different disciplines like medicine, electronics, mechanics, and design. Furthermore, designing affordable devices and systems to benefit all mankind is a great challenge ahead. The multi-disciplinary nature of the R&D effort in this area provides a new perspective for the future mechanical engineers.

  1. Noncontact optical measurement of lens capsule thickness ex vivo

    NASA Astrophysics Data System (ADS)

    Ziebarth, Noel M.; Manns, Fabrice; Uhlhorn, Stephen; Parel, Jean-Marie

    2004-07-01

    Purpose: To design a non-contact optical system to measure lens capsule thickness in cadaver eyes. Methods: The optical system uses a 670nm laser beam delivered to a single-mode fiber coupler. The output of the fiber coupler is focused onto the tissue using an aspheric lens (NA=0.68) mounted on a motorized translation stage. Light reflected from the sample is collected by the fiber coupler and sent to a silicon photodiode connected to a power meter. Peaks in the power signal are detected when the focal point of the aspheric lens coincides with the capsule boundaries. The capsule thickness is proportional to the distance between successive peaks. Anterior and posterior lens capsule thickness measurements were performed on 13 human, 10 monkey, and 34 New Zealand white rabbit lenses. The cadaver eyes were prepared for optical measurements by bonding a PMMA ring on the sclera. The posterior pole was sectioned, excess vitreous was removed, and the eye was placed on a Teflon slide. The cornea and iris were then sectioned. After the experiments, the lenses were excised, placed in 10% buffered formalin, and prepared for histology. Results: Central anterior lens capsule thickness was 9.4+/-2.9μm (human), 11.2+/-6.6μm (monkey), and 10.3+/-3.6μm (rabbit) optically and 14.9+/-1.6μm (human), 17.7+/-4.9μm (monkey), and 12.6+/-2.3μm (rabbit) histologically. The values for the central posterior capsule were 9.4+/-2.9μm (human), 6.6+/-2.5μm (monkey), and 7.9+/-2.3μm (rabbit) optically and 4.6+/-1.4μm (human), 4.5+/-1.2μm (monkey), and 5.7+/-1.7μm (rabbit) histologically. Conclusions: This study demonstrates that a non-contact optical system can successfully measure lens capsule thickness in cadaver eyes.

  2. In Vivo Needle-Based Electromechanical Reshaping of Pinnae

    PubMed Central

    Yau, Amy Y. Y.; Manuel, Cyrus; Hussain, Syed F.; Protsenko, Dmitry E.; Wong, Brian J. F.

    2014-01-01

    IMPORTANCE Electromechanical reshaping (EMR) is a low-cost, needle-based, and simple means to shape cartilage tissue without the use of scalpels, sutures, or heat that can potentially be used in an outpatient setting to perform otoplasty. OBJECTIVES To demonstrate that EMR can alter the shape of intact pinnae in an in vivo animal model and to show that the amount of shape change and the limited cell injury are proportional to the dosimetry. DESIGN, SETTING, AND SPECIMENS In an academic research setting, intact ears of 18 New Zealand white rabbits underwent EMR using 6 different dosimetry parameters (4 V for 5 minutes, 4 V for 4 minutes, 5 V for 3 minutes, 5 V for 4 minutes, 6 V for 2 minutes, and 6 V for 3 minutes). A custom acrylic jig with 2 rows of platinum needle electrodes was used to bend ears at the middle of the pinna and to perform EMR. Treatment was repeated twice per pinna, in proximal and distal locations. Control pinnae were not subjected to current application when being bent and perforated within the jig. Pinnae were splinted for 3 months along the region of the bend using soft silicon sheeting and a cotton bolster. MAIN OUTCOMES AND MEASURES The ears were harvested the day after splints were removed and before euthanasia. Photographs of ears were obtained, and bend angles were measured. Tissue was sectioned for histologic examination and confocal microscopy to assess changes to microscopic structure and cellular viability. RESULTS Treated pinnae were bent more and retained shape better than control pinnae. The mean (SD) bend angles in the 7 dosimetry groups were 55° (35°) for the control, 60° (15°) for 4 V for 4 minutes, 118° (15°) for 4 V for 5 minutes, 88° (26°) for 5 V for 3 minutes, 80° (17°) for 5 V for 4 minutes, 117° (21°) for 6 V for 2 minutes, and 125° (18°) for 6 V for 3 minutes. Shape change was proportional to electrical charge transfer, which increased with voltage and application time. Hematoxylin-eosin staining of the

  3. Radio Frequency (RF) Micro-Electromechanical Systems (MEMS) Switches for Space Communications

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Ponchak, George E.; Scardelletti, Maximillian C.; Varaljay, Nicholas C.

    2000-01-01

    Micro-electromechanical systems (MEMS) is an emerging technology for radio frequency (RF) systems because it has the potential to dramatically decrease loss and improve efficiency. In this paper, we address the design and fabrication of novel MEMS switches being developed at NASA Glenn Research Center. Two types of switches are being developed: a microstrip series single pole single throw (SPST) switch and a coplanar waveguide (CPW) series SPST and single pole double throw (SPDT) switches. These are being fabricated as an integral part of 50 Ohm microstrip and CPW RF integrated circuits using microfabrication techniques. The construction of the switch relies on a cantilever beam that is partially supported by a dielectric post. The cantilever beam is electro-magnetically actuated. To decrease stiction, a Si3N4 thin film is deposited over the contact area. Thus, when the switch is closed, the ON-state insertion loss is governed by the parallel plate capacitance formed by the two contacts. The isolation in the OFF-state is governed by the parasitic capacitance when the cantilever is in the up position. RF MEMS switches have been demonstrated with 80% lower insertion loss than conventional solid state devices (GaAs Metal Semiconductor Field Effect Transistors (MESFETs) and Silicon PIN diodes) based switches. For example, a conventional GaAs five-bit phase shifter which is required for beam steering in a phased array antenna has approximately 7 dB of insertion loss at 26.5 GHz where as a comparable MEMS based phase shifter is expected to have only 2 dB of insertion loss. This translates into 56% lower power dissipation and therefore decreases the thermal load on the spacecraft and also reduces the power amplifier requirements. These benefits will enable NASA to build the next generation of deep space science crafts and micro/nano satellites.

  4. An electromechanically reconfigurable plasmonic metamaterial operating in the near-infrared.

    PubMed

    Ou, Jun-Yu; Plum, Eric; Zhang, Jianfa; Zheludev, Nikolay I

    2013-04-01

    Current efforts in metamaterials research focus on attaining dynamic functionalities such as tunability, switching and modulation of electromagnetic waves. To this end, various approaches have emerged, including embedded varactors, phase-change media, the use of liquid crystals, electrical modulation with graphene and superconductors, and carrier injection or depletion in semiconductor substrates. However, tuning, switching and modulating metamaterial properties in the visible and near-infrared range remain major technological challenges: indeed, the existing microelectromechanical solutions used for the sub-terahertz and terahertz regimes cannot be shrunk by two to three orders of magnitude to enter the optical spectral range. Here, we develop a new type of metamaterial operating in the optical part of the spectrum that is three orders of magnitude faster than previously reported electrically reconfigurable metamaterials. The metamaterial is actuated by electrostatic forces arising from the application of only a few volts to its nanoscale building blocks-the plasmonic metamolecules-that are supported by pairs of parallel strings cut from a flexible silicon nitride membrane of nanoscale thickness. These strings, of picogram mass, can be driven synchronously to megahertz frequencies to electromechanically reconfigure the metamolecules and dramatically change the transmission and reflection spectra of the metamaterial. The metamaterial's colossal electro-optical response (on the order of 10(-5)-10(-6) m V(-1)) allows for either fast continuous tuning of its optical properties (up to 8% optical signal modulation at up to megahertz rates) or high-contrast irreversible switching in a device only 100 nm thick, without the need for external polarizers and analysers. PMID:23503091

  5. An electromechanical finite element model for piezoelectric energy harvester plates

    NASA Astrophysics Data System (ADS)

    De Marqui Junior, Carlos; Erturk, Alper; Inman, Daniel J.

    2009-10-01

    Vibration-based energy harvesting has been investigated by several researchers over the last decade. The goal in this research field is to power small electronic components by converting the waste vibration energy available in their environment into electrical energy. Recent literature shows that piezoelectric transduction has received the most attention for vibration-to-electricity conversion. In practice, cantilevered beams and plates with piezoceramic layers are employed as piezoelectric energy harvesters. The existing piezoelectric energy harvester models are beam-type lumped parameter, approximate distributed parameter and analytical distributed parameter solutions. However, aspect ratios of piezoelectric energy harvesters in several cases are plate-like and predicting the power output to general (symmetric and asymmetric) excitations requires a plate-type formulation which has not been covered in the energy harvesting literature. In this paper, an electromechanically coupled finite element (FE) plate model is presented for predicting the electrical power output of piezoelectric energy harvester plates. Generalized Hamilton's principle for electroelastic bodies is reviewed and the FE model is derived based on the Kirchhoff plate assumptions as typical piezoelectric energy harvesters are thin structures. Presence of conductive electrodes is taken into account in the FE model. The predictions of the FE model are verified against the analytical solution for a unimorph cantilever and then against the experimental and analytical results of a bimorph cantilever with a tip mass reported in the literature. Finally, an optimization problem is solved where the aluminum wing spar of an unmanned air vehicle (UAV) is modified to obtain a generator spar by embedding piezoceramics for the maximum electrical power without exceeding a prescribed mass addition limit.

  6. Electromechanical coupling factor of capacitive micromachined ultrasonic transducers

    NASA Astrophysics Data System (ADS)

    Caronti, Alessandro; Carotenuto, Riccardo; Pappalardo, Massimo

    2003-01-01

    Recently, a linear, analytical distributed model for capacitive micromachined ultrasonic transducers (CMUTs) was presented, and an electromechanical equivalent circuit based on the theory reported was used to describe the behavior of the transducer [IEEE Trans. Ultrason. Ferroelectr. Freq. Control 49, 159-168 (2002)]. The distributed model is applied here to calculate the dynamic coupling factor kw of a lossless CMUT, based on a definition that involves the energies stored in a dynamic vibration cycle, and the results are compared with those obtained with a lumped model. A strong discrepancy is found between the two models as the bias voltage increases. The lumped model predicts an increasing dynamic k factor up to unity, whereas the distributed model predicts a more realistic saturation of this parameter to values substantially lower. It is demonstrated that the maximum value of kw, corresponding to an operating point close to the diaphragm collapse, is 0.4 for a CMUT single cell with a circular membrane diaphragm and no parasitic capacitance (0.36 for a cell with a circular plate diaphragm). This means that the dynamic coupling factor of a CMUT is comparable to that of a piezoceramic plate oscillating in the thickness mode. Parasitic capacitance decreases the value of kw, because it does not contribute to the energy conversion. The effective coupling factor keff is also investigated, showing that this parameter coincides with kw within the lumped model approximation, but a quite different result is obtained if a computation is made with the more accurate distributed model. As a consequence, keff, which can be measured from the transducer electrical impedance, does not give a reliable value of the actual dynamic coupling factor.

  7. Design and application of electromechanical actuators for deep space missions

    NASA Technical Reports Server (NTRS)

    Haskew, Tim A.; Wander, John

    1994-01-01

    This progress report documents research and development efforts performed from August 16, 1993 through February 15, 1994 on NASA Grant NAG8-240, 'Design and Application of Electromechanical Actuators for Deep Space Missions.' Following the executive summary are four report sections: Motor Selection, Tests Stand Development, Health Monitoring and Fault Management, and Experiment Planning. Three specific motor types have been considered as prime movers for TVC EMA applications: the brushless dc motor, the permanent magnet synchronous motor, and the induction motor. The fundamental finding was that, in general, the primary performance issues were energy efficiency and thermal dissipation (rotor heating). In terms of all other issues, the three motor types were found to compare quite equally. Among the design changes made to the test stand since the last progress report is the addition of more mounting holes in the side beams. These additional holes allow the movable end beam to be attached in a greater number of positions than previously. With this change the movable end beam can move from full forward to full back in three inch increments. Specific mathematical details on the approach that have been employed for health monitoring and fault management (HMFM) have been reported previously. This approach is based on and adaptive Kalman filter strategy. In general, a bank of filters can be implemented for each primary fault type. Presently under consideration for the brushless dc machine are the following faults: armature winding open-circuits, armature winding short-circuits (phase-to-phase and phase-to-ground), bearing degradation, and rotor flux weakening. The mechanically oriented experiments include transient loading experiments, transverse loading experiment, friction experiment, motor performance experiment, and HMFM experiment.

  8. Sequential afterglow processing and non-contact Corona-Kelvin metrology of 4H-silicon carbide

    NASA Astrophysics Data System (ADS)

    Short, Eugene L., III

    Silicon carbide (SiC) is a wide band-gap semiconductor with advantageous electrical and thermal properties making it attractive for high temperature and power applications. However, difficulties with oxide/SiC structures have posed challenges to the development of practical MOS-type devices. Surface conditioning and oxidation of 4H-SiC were investigated using a novel sequential afterglow processing approach combined with the unique capabilities of non-contact corona-Kelvin metrology. The use of remote plasma assisted thermal oxidation facilitated film growth at low temperature and pressure with the flexibility of sequential in-situ processing options including pre-oxidation surface conditioning. Corona-Kelvin metrology (C-KM) provided a fast, nondestructive method for electrical evaluation of oxide films and semiconductor surfaces. Non-contact C-KM oxide capacitance-voltage characteristics combined with direct measurement of SiC surfaces using C-KM depletion surface barrier monitoring and XPS analysis of surface chemistry were interpreted relating the impact of afterglow conditioning on the surface and its influence on subsequent oxide thin film growth. Afterglow oxide films of thicknesses 50--500 A were fabricated on SiC epi-layers at low growth temperatures in the range 600--850°C, an achievement not possible using conventional atmospheric oxidation techniques. The inclusion of pre-oxidation surface conditioning in forming gas (N2:H2)* afterglow was found to produce an increase in oxide growth rate (10--25%) and a significant improvement in oxide film thickness uniformity. Analysis of depletion voltage transients on conditioned SiC surfaces revealed the highest degree of surface passivation, uniformity, and elimination of sources of charge compensation accomplished by the (N2:H2)* afterglow treatment for 20 min. at 600--700°C compared to other conditioning variations. The state of surface passivation was determined to be very stable and resilient when exposed

  9. Combined non-contact coordinate measurement system and calibration method

    NASA Astrophysics Data System (ADS)

    Fan, Yiyan; Zhao, Bin

    2015-07-01

    A combined non-contact measurement system comprising attitude angle sensor, angle encoder, laser rangefinder, and total station is adopted to measure the spatial coordinate of the hidden zones in large-scale space. The laser from the total station is aimed at the optical system of the attitude angle sensor to obtain the spatial coordinate and the spatial attitude angles. Then, the angle encoder driven by a stepping motor is rotated to drive the laser rangefinder to direct at the measured point. This approach is used to obtain the distance from the rangefinder to the measured point and the angle of the angle encoder. Finally, the spatial coordinates of the measured point can be calculated by using these measured parameters. For the measurement system, we propose a weighted least squares (WLS) calibration method, in which weights are determined for the angular distribution density. Experimental results show that the measurement system could expand the scale and achieve reliable precision during combined measurement and the measurement error of the weighted least squares method is less than that of the ordinary least square (OLS) method.

  10. Non-contact temperature measurement of a falling drop

    NASA Technical Reports Server (NTRS)

    Hofmeister, William; Bayuzick, R. J.; Robinson, M. B.

    1989-01-01

    The 105 meter drop tube at NASA-Marshall has been used in a number of experiments to determine the effects of containerless, microgravity processing on the undercooling and solidification behavior of metals and alloys. These experiments have been limited, however, because direct temperature measurement of the falling drops has not been available. Undercooling and nucleation temperatures are calculated from thermophysical properties based on droplet cooling models. In most cases these properties are not well known, particularly in the undercooled state. This results in a large amount of uncertainty in the determination of nucleation temperatures. If temperature measurement can be accomplished then the thermal history of the drops could be well documented. This would lead to a better understanding of the thermophysical and thermal radiative properties of undercooled melts. An effort to measure the temperature of a falling drop is under way. The technique uses two color pyrometry and high speed data acquisition. The approach is presented along with some preliminary data from drop tube experiments. The results from droplet cooling models is compared with noncontact temperature measurements.

  11. Noncontact friction and relaxational dynamics of surface defects.

    PubMed

    She, Jian-Huang; Balatsky, Alexander V

    2012-03-30

    The motion of a cantilever near sample surfaces exhibits additional friction even before two bodies come into mechanical contact. Called noncontact friction (NCF), this friction is of great practical importance to the ultrasensitive force detection measurements. The observed large NCF of a micron-scale cantilever found an anomalously large damping that exceeds theoretical predictions by 8-11 orders of magnitude. This finding points to a contribution beyond fluctuating electromagnetic fields within the van der Waals approach. Recent experiments reported by Saitoh et al. [Phys. Rev. Lett. 105, 236103 (2010)] also found a nontrivial distance dependence of NCF. Motivated by these observations, we propose a mechanism based on the coupling of a cantilever to the relaxation dynamics of surface defects. We assume that the surface defects couple to the cantilever tip via spin-spin coupling and their spin relaxation dynamics gives rise to the backaction terms and modifies both the friction coefficient and the spring constant. We explain the magnitude, as well as the distance dependence of the friction due to these backaction terms. Reasonable agreement is found with the experiments. PMID:22540716

  12. Non-contact tamper sensing by electronic means

    DOEpatents

    Gritton, Dale G.

    1993-01-01

    A tamper-sensing system for an electronic tag 10 which is to be fixed to a surface 11 of an article 12, the tamper-sensing system comprising a capacitor having two non-contacting, capacitively-coupled elements 16, 19. Fixing of the body to the article will establish a precise location of the capacitor elements 16 and 19 relative to each other. When interrogated, the tag will generate a tamper-sensing signal having a value which is a function of the amount of capacity of the capacitor elements. The precise relative location of the capacitor elements cannot be duplicated if the tag is removed and affixed to a surrogate article having a fiducial capacitor element 19 fixed thereto. A very small displacement, in the order of 2-10 microns, of the capacitor elements relative to each other if the tag body is removed and fixed to a surrogate article will result in the tamper-sensing signal having a different, and detectable, value when the tag is interrogated.

  13. Modular Architecture of a Non-Contact Pinch Actuation Micropump

    PubMed Central

    Chee, Pei Song; Arsat, Rashidah; Adam, Tijjani; Hashim, Uda; Rahim, Ruzairi Abdul; Leow, Pei Ling

    2012-01-01

    This paper demonstrates a modular architecture of a non-contact actuation micropump setup. Rapid hot embossing prototyping was employed in micropump fabrication by using printed circuit board (PCB) as a mold material in polymer casting. Actuator-membrane gap separation was studied, with experimental investigation of three separation distances: 2.0 mm, 2.5 mm and 3.5 mm. To enhance the micropump performance, interaction surface area between plunger and membrane was modeled via finite element analysis (FEA). The micropump was evaluated against two frequency ranges, which comprised a low driving frequency range (0–5 Hz, with 0.5 Hz step increments) and a nominal frequency range (0–80 Hz, with 10 Hz per step increments). The low range frequency features a linear relationship of flow rate with the operating frequency function, while two magnitude peaks were captured in the flow rate and back pressure characteristic in the nominal frequency range. Repeatability and reliability tests conducted suggest the pump performed at a maximum flow rate of 5.78 mL/min at 65 Hz and a backpressure of 1.35 kPa at 60 Hz.

  14. Dual Modality Noncontact Photoacoustic and Spectral Domain OCT Imaging

    PubMed Central

    Leiss-Holzinger, Elisabeth; Bauer-Marschallinger, Johannes; Hochreiner, Armin; Hollinger, Philipp; Berer, Thomas

    2016-01-01

    We developed a multimodal imaging system, combining noncontact photoacoustic imaging and optical coherence tomography (OCT). Photoacoustic signals are recorded without contact to the specimens’ surface by using an interferometric technique. The interferometer is realized within a fiber-optic network using a fiber laser at 1550 nm as source. The fiber-optic network allows the integration of a fiber-based OCT system operating at a wavelength region around 1310 nm. Light from the fiber laser and the OCT source are multiplexed into one fiber using wavelength-division multiplexing. The same focusing optics is used for both modalities. Back-reflected light from the sample is demultiplexed and guided to the respective imaging systems. As the same optical components are used for OCT and photoacoustic imaging, the obtained images are co-registered intrinsically in lateral direction. Three-dimensional imaging is implemented by hybrid galvanometer and mechanical scanning. To allow fast B-scan measurements, scanning of the interrogation beam along one dimension is executed by a galvanometer scanner. Slow-axis scanning, perpendicular to the fast axis, is performed utilizing a linear translational stage. We demonstrate two-dimensional and three-dimensional imaging on agarose phantoms. PMID:25900968

  15. Noncontact respiration-monitoring system using fiber grating sensor

    NASA Astrophysics Data System (ADS)

    Sato, Isao; Nakajima, Masato

    2004-10-01

    In this research, the new non-contact breathing motion monitoring system using Fiber Grating 3-dimension Sensor is used to measure the respiratory movement of the chest and the abdomen and the shape of the human body simultaneously. Respiratory trouble during sleep brings about various kinds of diseases. Particularly, Sleep Apnea Syndrome (SAS), which restricts respiration during sleep, has been in the spotlight in recent years. However, present equipment for analyzing the blessing motion requires attaching various sensors on the patient's body. This system adopted two CCD cameras to measure the movements of projected infrared bright spots on the patient's body which measure the body form, breathing motion of the chest and breathing motion of the abdomen in detail. Since the equipment does not contact the patient's body, the patient feels incompatibility, and there is no necessity to worry about the equipment coming off. Sleep Apnea Syndrome is classified into three types by their respiratory pattern-Obstructive, Central and Mixed SAS based on the characteristic. This paper reports the method of diagnosing SAS automatically. It is thought that this method will be helpful not only for the diagnosis of SAS but also for the diagnosis of other kinds of complicated respiratory disease.

  16. Anthropometry of external auditory canal by non-contactable measurement.

    PubMed

    Yu, Jen-Fang; Lee, Kun-Che; Wang, Ren-Hung; Chen, Yen-Sheng; Fan, Chun-Chieh; Peng, Ying-Chin; Tu, Tsung-Hsien; Chen, Ching-I; Lin, Kuei-Yi

    2015-09-01

    Human ear canals cannot be measured directly with existing general measurement tools. Furthermore, general non-contact optical methods can only conduct simple peripheral measurements of the auricle and cannot obtain the internal ear canal shape-related measurement data. Therefore, this study uses the computed tomography (CT) technology to measure the geometric shape of the ear canal and the shape of the ear canal using a non-invasive method, and to complete the anthropometry of external auditory canal. The results of the study show that the average height and width of ear canal openings, and the average depth of the first bend for men are generally longer, wider and deeper than those for women. In addition, the difference between the height and width of the ear canal opening is about 40% (p < 0.05). Hence, the circular cross-section shape of the earplugs should be replaced with an elliptical cross-section shape during manufacturing for better fitting.

  17. Noncontact characterization of static paper materials using a photorefractive interferometer

    NASA Astrophysics Data System (ADS)

    Lafond, Emmanuel F.; Gerhardstein, Joseph P.; Brodeur, Pierre H.

    1999-02-01

    Laser-Based Ultrasound (LBU) systems are now entering their maturity years by penetrating the factory in both the areas of non-destructive testing and process control. A LBU system can be used for the on-line characterization of a paper web in a paper mill. Compared to contact techniques, LBU is able to generate and detect on a paper web both symmetric and antisymmetric waves with a non-contact tool which is the spot of the generation laser. This provides all at once a rich amount of data about the stiffness properties of the sheet. To demonstrate this concept we made some experiments on static paper first, our ultimate goal being to monitor the stiffness properties of a paper web, on-line, at industrial speeds. A photorefractive interferometer using the two-wave mixing method with a continuous electric field applied to a BSO crystal has been built for ultrasound detection. Results are presented on different paper grades, using a Nd:YAG laser for generation. Both A0 (anti- symmetric) and S0 (symmetric) modes of Lamb waves have been detected with acceptable signal to noise ratio in single laser shot. The dispersive nature of A0 wave is clearly visible as well as the higher frequency content of S0 wave.

  18. Morphological evaluation of meibomian glands using noncontact infrared meibography.

    PubMed

    Ban, Yumiko; Shimazaki-Den, Seika; Tsubota, Kazuo; Shimazaki, Jun

    2013-01-01

    Meibography is used to study morphological changes in the meibomian glands (MGs), and semiquantitative analysis has been used for MG assessment. We conducted a detailed morphometric assessment of MGs using noncontact infrared meibography (NIM) and investigated the relationship between MG morphology and the ocular surface and MG morphology associated with aging and sex in 37 subjects. The MGs in the upper and lower eyelids showed significant correlations in their morphology, with the former having longer ducts than the latter. The mean length of the MG ducts, percent area of MG acini, and number of gland dropouts were significantly correlated with age. The mean length of the MG ducts in the upper and lower eyelids showed negative correlations with the meibum (P=.043) and fluorescein staining score (P=.008), respectively. The percent area of MG acini in the upper eyelid showed a positive correlation with tear film breakup time (P=.012) and negative correlations with tear film lipid layer interferometry and meibum (P=.005 and .002, respectively). The mean length of the male's MG ducts in the lower eyelid was significantly longer than that of the females (P=.03). These results indicate that morphometric analysis using NIM may be useful for assessing ocular surface conditions.

  19. Dual Modality Noncontact Photoacoustic and Spectral Domain OCT Imaging.

    PubMed

    Leiss-Holzinger, Elisabeth; Bauer-Marschallinger, Johannes; Hochreiner, Armin; Hollinger, Philipp; Berer, Thomas

    2016-01-01

    We developed a multimodal imaging system, combining noncontact photoacoustic imaging and optical coherence tomography (OCT). Photoacoustic signals are recorded without contact to the specimens' surface by using an interferometric technique. The interferometer is realized within a fiber-optic network using a fiber laser at 1550 nm as source. The fiber-optic network allows the integration of a fiber-based OCT system operating at a wavelength region around 1310 nm. Light from the fiber laser and the OCT source are multiplexed into one fiber using wavelength-division multiplexing. The same focusing optics is used for both modalities. Back-reflected light from the sample is demultiplexed and guided to the respective imaging systems. As the same optical components are used for OCT and photoacoustic imaging, the obtained images are co-registered intrinsically in lateral direction. Three-dimensional imaging is implemented by hybrid galvanometer and mechanical scanning. To allow fast B-scan measurements, scanning of the interrogation beam along one dimension is executed by a galvanometer scanner. Slow-axis scanning, perpendicular to the fast axis, is performed utilizing a linear translational stage. We demonstrate two-dimensional and three-dimensional imaging on agarose phantoms.

  20. Non-Contact Measurements of Creep Properties of Refractory Materials

    NASA Technical Reports Server (NTRS)

    Lee, Jonghyun; Bradshaw, Richard C.; Hyers, Robert W.; Rogers, Jan R.; Rathz, Thomas J.; Wall, James J.; Choo, Hahn; Liaw, Peter

    2006-01-01

    State-of-the-art technologies for hypersonic aircraft, nuclear electric/thermal propulsion for spacecraft, and more efficient jet engines are driving ever more demanding needs for high-temperature (>2000 C) materials. At such high temperatures, creep rises as one of the most important design factors to be considered. Since conventional measurement techniques for creep resistance are limited to about 17OO0C, a new technique is in demand for higher temperatures. This paper presents a non-contact method using electrostatic levitation (ESL) which is applicable to both metallic and non-metallic materials. The samples were rotated quickly enough to cause creep deformation by centrifugal acceleration. The deformation of the samples was captured with a high speed camera and then the images were analyzed to estimate creep resistance. Finite element analyses were performed and compared to the experiments to verify the new method. Results are presented for niobium and tungsten, representative refractory materials at 2300 C and 2700 C respectively.

  1. A Novel Multidirectional, Non-Contact Strain-Sensing Nanocomposite

    NASA Astrophysics Data System (ADS)

    Withey, Paul; Vemuru, Srivishnu; Bachilo, Sergei; Nagarajaiah, Satish; Weisman, R. Bruce

    2013-03-01

    Single-walled carbon nanotubes (SWCNTs) have been successfully dispersed in a polymeric host resulting in the development of a novel strain-sensitive nanocomposite material with promise for scalability. Dubbed ``strain paint'' this new material when coated onto a surface becomes a smart-skin sensor that can detect strain through load transfer from the polymeric host to embedded SWCNTs. Strain is easily measured in a non-contact manner via laser excitation and detection of the unique near-infrared (NIR) fluorescence spectrum of semiconducting SWCNTs. When strained, each (n , m) SWCNT type exhibits a predictable shift in its NIR fluorescence peak. SWCNTs with high intensity are easily detected in the bulk fluorescence spectrum of raw, unsorted SWCNTs embedded in the polymer. Thin films of the polymer/SWCNT nanocomposite were spin-coated onto substrates, strains typically up to 1% were applied, and strain magnitudes were determined by resistive strain gauges bonded to the coating and substrate. Spectral shifts reveal a linear response to strain with little hysteresis. Two SWCNT types exhibiting opposite spectral shifts with strain were used to improve sensitivity. Strain along any direction is determined simply by adjusting the polarization of the excitation laser.

  2. A standing wave-type noncontact linear ultrasonic motor.

    PubMed

    Hu, J; Li, G; Chan, H L; Choy, C L

    2001-05-01

    In this study, a novel standing wave-type noncontact linear ultrasonic motor is proposed and analyzed. This linear ultrasonic motor uses a properly controlled ultrasonic standing wave to levitate and drive a slider. A prototype of the motor was constructed by using a wedge-shaped aluminum stator, which was placed horizontally and driven by a multilayer PZT vibrator. The levitation and motion of the slider were observed. Assuming that the driving force was generated by the turbulent acoustic streaming in the boundary air layer next to the bottom surface of the slider, a theoretical model was developed. The calculated characteristics of this motor were found to agree quite well with the experimental results. Based on the experimental and theoretical results, guidelines for increasing the displacement and speed of the slider were obtained. It was found that increasing the stator vibration displacement, or decreasing the gradient of the stator vibration velocity and the weight per unit area of the slider, led to an increase of the slider displacement. It was also found that increasing the amplitude and gradient of the stator vibration velocity, or decreasing the weight per unit area of the slider and the driving frequency, gave rise to an increase of the slider speed. There exists an optimum roughness of the bottom surface of the slider at which the slider speed has a maximum. PMID:11381693

  3. High magnetic field ohmically decoupled non-contact technology

    DOEpatents

    Wilgen, John [Oak Ridge, TN; Kisner, Roger [Knoxville, TN; Ludtka, Gerard [Oak Ridge, TN; Ludtka, Gail [Oak Ridge, TN; Jaramillo, Roger [Knoxville, TN

    2009-05-19

    Methods and apparatus are described for high magnetic field ohmically decoupled non-contact treatment of conductive materials in a high magnetic field. A method includes applying a high magnetic field to at least a portion of a conductive material; and applying an inductive magnetic field to at least a fraction of the conductive material to induce a surface current within the fraction of the conductive material, the surface current generating a substantially bi-directional force that defines a vibration. The high magnetic field and the inductive magnetic field are substantially confocal, the fraction of the conductive material is located within the portion of the conductive material and ohmic heating from the surface current is ohmically decoupled from the vibration. An apparatus includes a high magnetic field coil defining an applied high magnetic field; an inductive magnetic field coil coupled to the high magnetic field coil, the inductive magnetic field coil defining an applied inductive magnetic field; and a processing zone located within both the applied high magnetic field and the applied inductive magnetic field. The high magnetic field and the inductive magnetic field are substantially confocal, and ohmic heating of a conductive material located in the processing zone is ohmically decoupled from a vibration of the conductive material.

  4. Noncontact diffuse correlation tomography of human breast tumor

    PubMed Central

    He, Lian; Lin, Yu; Huang, Chong; Irwin, Daniel; Szabunio, Margaret M.; Yu, Guoqiang

    2015-01-01

    Abstract. Our first step to adapt our recently developed noncontact diffuse correlation tomography (ncDCT) system for three-dimensional (3-D) imaging of blood flow distribution in human breast tumors is reported. A commercial 3-D camera was used to obtain breast surface geometry, which was then converted to a solid volume mesh. An ncDCT probe scanned over a region of interest on the mesh surface and the measured boundary data were combined with a finite element framework for 3-D image reconstruction of blood flow distribution. This technique was tested in computer simulations and in vivo human breasts with low-grade carcinoma. Results from computer simulations suggest that relatively high accuracy can be achieved when the entire tumor is within the sensitive region of diffuse light. Image reconstruction with a priori knowledge of the tumor volume and location can significantly improve the accuracy in recovery of tumor blood flow contrasts. In vivo imaging results from two breast carcinomas show higher average blood flow contrasts (5.9- and 10.9-fold) in the tumor regions compared to the surrounding tissues, which are comparable with previous findings using diffuse correlation spectroscopy. The ncDCT system has the potential to image blood flow distributions in soft and vulnerable tissues without distorting tissue hemodynamics. PMID:26259706

  5. Dose control for noncontact laser coagulation of tissue

    NASA Astrophysics Data System (ADS)

    Roggan, Andre; Albrecht, Hansjoerg; Bocher, Thomas; Rygiel, Reiner; Winter, Harald; Mueller, Gerhard J.

    1995-01-01

    Nd:YAG lasers emitting at 1064 nm are often used for coagulation of tissue in a non-contact mode, i.e. the treatment of verrucae, endometriosis, tumor coagulation and hemostasis. During this process an uncontrolled temperature rise of the irradiated area leads to vaporization and, finally, to a carbonization of the tissue surface. To prevent this, a dose controlled system was developed using an on-line regulation of the output laser power. The change of the backscattered intensity (remission) of the primary beam was used as a dose dependent feedback parameter. Its dependence on the temperature was determined with a double integrating sphere system and Monte-Carlo simulations. The remission of the tissue was calculated in slab geometry from diffusion theory and Monte-Carlo simulations. The laser control was realized with a PD-circuit and an A/D-converter, enabling the direct connection to the internal bus of the laser system. Preliminary studies with various tissues revealed the practicability of the system.

  6. A Vision-Based Sensor for Noncontact Structural Displacement Measurement

    PubMed Central

    Feng, Dongming; Feng, Maria Q.; Ozer, Ekin; Fukuda, Yoshio

    2015-01-01

    Conventional displacement sensors have limitations in practical applications. This paper develops a vision sensor system for remote measurement of structural displacements. An advanced template matching algorithm, referred to as the upsampled cross correlation, is adopted and further developed into a software package for real-time displacement extraction from video images. By simply adjusting the upsampling factor, better subpixel resolution can be easily achieved to improve the measurement accuracy. The performance of the vision sensor is first evaluated through a laboratory shaking table test of a frame structure, in which the displacements at all the floors are measured by using one camera to track either high-contrast artificial targets or low-contrast natural targets on the structural surface such as bolts and nuts. Satisfactory agreements are observed between the displacements measured by the single camera and those measured by high-performance laser displacement sensors. Then field tests are carried out on a railway bridge and a pedestrian bridge, through which the accuracy of the vision sensor in both time and frequency domains is further confirmed in realistic field environments. Significant advantages of the noncontact vision sensor include its low cost, ease of operation, and flexibility to extract structural displacement at any point from a single measurement. PMID:26184197

  7. Dual Modality Noncontact Photoacoustic and Spectral Domain OCT Imaging.

    PubMed

    Leiss-Holzinger, Elisabeth; Bauer-Marschallinger, Johannes; Hochreiner, Armin; Hollinger, Philipp; Berer, Thomas

    2016-01-01

    We developed a multimodal imaging system, combining noncontact photoacoustic imaging and optical coherence tomography (OCT). Photoacoustic signals are recorded without contact to the specimens' surface by using an interferometric technique. The interferometer is realized within a fiber-optic network using a fiber laser at 1550 nm as source. The fiber-optic network allows the integration of a fiber-based OCT system operating at a wavelength region around 1310 nm. Light from the fiber laser and the OCT source are multiplexed into one fiber using wavelength-division multiplexing. The same focusing optics is used for both modalities. Back-reflected light from the sample is demultiplexed and guided to the respective imaging systems. As the same optical components are used for OCT and photoacoustic imaging, the obtained images are co-registered intrinsically in lateral direction. Three-dimensional imaging is implemented by hybrid galvanometer and mechanical scanning. To allow fast B-scan measurements, scanning of the interrogation beam along one dimension is executed by a galvanometer scanner. Slow-axis scanning, perpendicular to the fast axis, is performed utilizing a linear translational stage. We demonstrate two-dimensional and three-dimensional imaging on agarose phantoms. PMID:25900968

  8. Anthropometry of external auditory canal by non-contactable measurement.

    PubMed

    Yu, Jen-Fang; Lee, Kun-Che; Wang, Ren-Hung; Chen, Yen-Sheng; Fan, Chun-Chieh; Peng, Ying-Chin; Tu, Tsung-Hsien; Chen, Ching-I; Lin, Kuei-Yi

    2015-09-01

    Human ear canals cannot be measured directly with existing general measurement tools. Furthermore, general non-contact optical methods can only conduct simple peripheral measurements of the auricle and cannot obtain the internal ear canal shape-related measurement data. Therefore, this study uses the computed tomography (CT) technology to measure the geometric shape of the ear canal and the shape of the ear canal using a non-invasive method, and to complete the anthropometry of external auditory canal. The results of the study show that the average height and width of ear canal openings, and the average depth of the first bend for men are generally longer, wider and deeper than those for women. In addition, the difference between the height and width of the ear canal opening is about 40% (p < 0.05). Hence, the circular cross-section shape of the earplugs should be replaced with an elliptical cross-section shape during manufacturing for better fitting. PMID:25959317

  9. Advances in Non-contact Measurement of Creep Properties

    NASA Technical Reports Server (NTRS)

    Hyers, Robert W.; Canepari, Stacy; Rogers, Jan. R.

    2009-01-01

    Our team has developed a novel approach to measuring creep at extremely high temperatures using electrostatic levitation (ESL). This method has been demonstrated on niobium up to 2300 C, while ESL has melted tungsten (3400 C). High-precision machined spheres of the sample are levitated in the NASA MSFC ESL, a national user facility, and heated with a laser. The laser is aligned off-center so that the absorbed photons transfer their momentum to the sample, causing it to rotate at up to 250,000+ RPM. The rapid rotation loads the sample through centripetal acceleration, causing it to deform. The deformation of the sample is captured on high-speed video, which is analyzed by machine-vision software from the University of Massachusetts. The deformations are compared to finite element models to determine the constitutive constants in the creep relation. Furthermore, the noncontact method exploits stress gradients within the sample to determine the stress exponent in a single test. This method was validated in collaboration with the University of Tennessee for niobium at 1985 C, with agreement within the uncertainty of the conventional measurements. A similar method is being employed on Ultra-High-Temperature ZrB2- SiC composites, which may see application in rocket nozzles and sharp leading edges for hypersonic vehicles.

  10. Investigation of a non-contact strain measurement technique

    SciTech Connect

    Talarico, L.J.; Damiano, B.

    1997-03-01

    The goal of this project was to investigate the feasibility of a new non-contact technique for directly and continuously monitoring peak strain in rotating components. The technique utilizes the unique strain-sensitive magnetic material properties of TRansformation Induced Plasticity (TRIP) steel alloys to measure strain. These alloys are weakly magnetic when unstrained but become strongly ferromagnetic after mechanical deformation. A computer study was performed to determine whether the strain-induced change in the magnetic material properties of a TRIP steel gage bonded to a rotating component would cause significant perturbations in the magnetic flux of a stationary electromagnet. The effects of strain level, distance between the rotating component and the stationary electromagnet, and motion-induced eddy currents on flux perturbation magnitude were investigated. The calculated results indicate that a TRIP steel strain sensing element can cause a significant perturbation in the magnetic flux of a stationary electromagnet. The magnetic flux perturbation magnitude was found to be inversely proportional to the distance between the magnet face and the TRIP steel element and directly proportional to the TRIP steel strain level. The effect of motion-induced eddy currents on the magnetic flux was found to be negligible. It appears that the technique can be successfully applied to measure peak strain in rotating components, however, the sensitivity of the magnetic flux perturbation magnitude to the distance between the strain sensing element and the electromagnet may require making an independent proximity measurement.

  11. Supported lipid bilayer microarrays created by non-contact printing.

    PubMed

    Kaufmann, Stefan; Sobek, Jens; Textor, Marcus; Reimhult, Erik

    2011-07-21

    Arrays of supported lipid bilayers (SLBs) provide great potential for future drug development and multiplexed biological research, but are difficult to prepare due to the sensitivity of both the lipid and protein structural arrangement to air exposure. A novel way to produce arrays of SLBs is presented based on non-contact dispensing of vesicles to a substrate through a thin surface confined water film. The approach presents many degrees of freedom since it is not limited to a specific substrate, lipid composition, linker or controlled environment. The method allows adjustment of spot size (180-360 μm) by repeated dispensing as well as control over the composition of the spots and subsequent analytes. SLB formation by vesicle adsorption and rupture allows for incorporation of membrane proteins through pre-formed proteoliposomes. Dispensing through a dip-and-rinse water film avoids contamination, disruptive drying and the need for complex buffer compositions. Furthermore, no humidity control is necessary which simplifies the production step and prolongs the life-time of the spotting system. We characterize the method with respect to control over spot size, bilayer mobility and the formation process as well as demonstrate the possibility to fuse bilayer spots with subsequently added vesicles. Since complex lipid compositions and multiple spotting nozzles can be used, this novel technique is expected to be a promising platform for future applications, e.g. patterning to monitor peptide/protein-lipid interactions, for glycomics using glycolipids or lipopolysaccharides, and to study mixing of spatially confined lipid membranes.

  12. Characteristic of torsional vibration of mill main drive excited by electromechanical coupling

    NASA Astrophysics Data System (ADS)

    Zhang, Yifang; Yan, Xiaoqiang; Lin, Qihui

    2016-01-01

    In the study of electromechanical coupling vibration of mill main drive system, the influence of electrical system on the mechanical transmission is considered generally, however the research for the mechanism of electromechanical interaction is lacked. In order to research the electromechanical coupling resonance of main drive system on the F3 mill in a plant, the cycloconverter and synchronous motor are modeled and simulated by the MTLAB/SIMULINK firstly, simulation result show that the current harmonic of the cycloconverter can lead to the pulsating torque of motor output. Then the natural characteristics of the mechanical drive system are calculated by ANSYS, the result show that the modal frequency contains the component which is close to the coupling vibration frequency of 42Hz. According to the simulation result of the mechanical and electrical system, the closed loop feedback model including the two systems are built, and the mechanism analysis of electromechanical coupling presents that there is the interaction between the current harmonic of electrical system and the speed of the mechanical drive system. At last, by building and computing the equivalent nonlinear dynamics model of the mechanical drive system, the dynamic characteristics of system changing with the stiffness, damping coefficient and the electromagnetic torque are obtained. Such electromechanical interaction process is suggested to consider in research of mill vibration, which can induce strong coupling vibration behavior in the rolling mill drive system.

  13. Evaluation of selected sorbent materials for the collection of volatile organic compounds related to human scent using non-contact sampling mode.

    PubMed

    DeGreeff, Lauryn E; Curran, Allison M; Furton, Kenneth G

    2011-06-15

    Human scent can be collected by either contact or non-contact sampling mode. The most frequently used human scent evidence collection device known as the Scent Transfer Unit (STU-100) is a dynamic sampling device and is often used in a non-contact mode. A customized human scent collection chamber was utilized in combination with controlled odor mimic permeation systems containing five standard human scent volatiles to optimize the flow rate, collection material and geometry of the absorbent material. The scent collection method which yielded the greatest amount of volatile organic compounds (VOCs) detected included the use of a single layer of Johnson and Johnson gauze/multiple layers of Dukal gauze with the STU-100 on the lowest flow rate setting. The correlation of the resulting VOC profiles demonstrate that collection of standard VOCs in controlled conditions yielded reproducible VOC profiles on all materials studied with the exception of polyester. Finally, the method was tested using actual human subjects under optimized set of conditions.

  14. Quantitative shear wave imaging optical coherence tomography for noncontact mechanical characterization of myocardium

    NASA Astrophysics Data System (ADS)

    Wang, Shang; Lopez, Andrew L.; Morikawa, Yuka; Tao, Ge; Li, Jiasong; Larina, Irina V.; Martin, James F.; Larin, Kirill V.

    2015-03-01

    Optical coherence elastography (OCE) is an emerging low-coherence imaging technique that provides noninvasive assessment of tissue biomechanics with high spatial resolution. Among various OCE methods, the capability of quantitative measurement of tissue elasticity is of great importance for tissue characterization and pathology detection across different samples. Here we report a quantitative OCE technique, termed quantitative shear wave imaging optical coherence tomography (Q-SWI-OCT), which enables noncontact measurement of tissue Young's modulus based on the ultra-fast imaging of the shear wave propagation inside the sample. A focused air-puff device is used to interrogate the tissue with a low-pressure short-duration air stream that stimulates a localized displacement with the scale at micron level. The propagation of this tissue deformation in the form of shear wave is captured by a phase-sensitive OCT system running with the scan of the M-mode imaging over the path of the wave propagation. The temporal characteristics of the shear wave is quantified based on the cross-correlation of the tissue deformation profiles at all the measurement locations, and linear regression is utilized to fit the data plotted in the domain of time delay versus wave propagation distance. The wave group velocity is thus calculated, which results in the quantitative measurement of the Young's modulus. As the feasibility demonstration, experiments are performed on tissuemimicking phantoms with different agar concentrations and the quantified elasticity values with Q-SWI-OCT agree well with the uniaxial compression tests. For functional characterization of myocardium with this OCE technique, we perform our pilot experiments on ex vivo mouse cardiac muscle tissues with two studies, including 1) elasticity difference of cardiac muscle under relaxation and contract conditions and 2) mechanical heterogeneity of the heart introduced by the muscle fiber orientation. Our results suggest the

  15. Superconductivity devices: Commercial use of space

    NASA Technical Reports Server (NTRS)

    Haertling, Gene; Furman, Eugene; Li, Guang

    1995-01-01

    The work described in this report covers various aspects of the Rainbow solid-state actuator technology. It is presented in six parts dealing with materials, processing, fabrication, properties and associated phenomena. The Rainbow actuator technology is a relatively new materials development which had its inception in 1992. It consists of a new processing technology for preparing piezoelectric and electrostrictive ceramic materials. It involves a high temperature chemical reduction process which leads to an internal pre-stressing of the oxide wafer, thus the name Rainbow, an acronym for Reduced And INternally Biased Oxide Wafer. Ceramics fabricated by this method produce bending-mode actuator devices which possess several times more displacement and load bearing capacity than present-day benders (unimorphs, bimorphs). It is anticipated that these solid-state, electromechanical actuators which can be used in a number of applications in space such as cryopump motors, anti-vibration active structures, autoleveling platforms, telescope mirror correctors and autofocusing devices. When considering any of these applications, the key to the development of a successful device is the successful development of a ceramic material which can produce maximum displacement per volt input; hence, this initiative involving a solid-state means for achieving unusually high electromechanical displacement can be significant and far reaching. An additional benefit obtained from employing the piezoelectric effect in these actuator devices is the ability to also utilize them as sensors; and, indeed, they can be used as both motor (actuator) and generator (sensor) in multifunction devices.

  16. Dynamic simulation of electromechanical systems: from Maxwell's theory to common-rail diesel injection.

    PubMed

    Kurz, S; Becker, U; Maisch, H

    2001-05-01

    This paper describes the state-of-the-art of dynamic simulation of electromechanical systems. Electromechanical systems can be split into electromagnetic and mechanical subsystems, which are described by Maxwell's equations and by Newton's law, respectively. Since such systems contain moving parts, the concepts of Lorentz and Galilean relativity are briefly addressed. The laws of physics are formulated in terms of (partial) differential equations. Numerical methods ultimately aim at linear systems of equations, which can be solved efficiently on digital computers. The various discretization methods for performing this task are discussed. Special emphasis is placed on domain decomposition as a framework for the coupling of different numerical methods such as the finite element method and the boundary element method. The paper concludes with descriptions of some applications of industrial relevance: a high performance injection valve and an electromechanical relay.

  17. Development of an electromechanical admittance approach for application in the vibration control of intelligent structures

    NASA Astrophysics Data System (ADS)

    Providakis, C. P.; Kontoni, D.-P. N.; Voutetaki, M. E.

    2007-04-01

    The present work considers the possibility of vibration control of a distributed dynamical system, such as flexible plates using local piezoelectric (PZT) actuators/sensors and the electromechanical admittance concept. When PZT actuators bonded on structures are used in active vibration and acoustic control, the desired deformation field in the structure is obtained through the application of localized line forces and moments generated by applying an appropriate electrical field on the outer surfaces of the PZT patches. The electromechanical admittance generated at the electrical terminals of a PZT-driven smart structure is then extracted to synthesize a desired damping performance. This is achieved by a FEM-based minimization of the difference between the computed and the desired electromechanical admittance signature for investigated frequency ranges.

  18. Green design assessment of electromechanical products based on group weighted-AHP

    NASA Astrophysics Data System (ADS)

    Guo, Jinwei; Zhou, MengChu; Li, Zhiwu; Xie, Huiguang

    2015-11-01

    Manufacturing industry is the backbone of a country's economy while environmental pollution is a serious problem that human beings must face today. The green design of electromechanical products based on enterprise information systems is an important method to solve the environmental problem. The question on how to design green products must be answered by excellent designers via both advanced design methods and effective assessment methods of electromechanical products. Making an objective and precise assessment of green design is one of the problems that must be solved when green design is conducted. An assessment method of green design on electromechanical products based on Group Weighted-AHP (Analytic Hierarchy Process) is proposed in this paper, together with the characteristics of green products. The assessment steps of green design are also established. The results are illustrated via the assessment of a refrigerator design.

  19. Large conversion of energy in dielectric elastomers by electromechanical phase transition

    NASA Astrophysics Data System (ADS)

    Lu, Tong-Qing; Suo, Zhi-Gang

    2012-08-01

    When air is pumped in, a tubular balloon initially inflates slightly and homogeneously. A short section of the balloon then forms a bulge, which coexists with the unbulged section of the balloon. As more air is pumped in, the bulged section elongates at the expense of the unbulged section, until the entire balloon is bulged. The phenomenon is analogous to the liquid-to-vapor phase transition. Here we study the bulging transition in a dielectric elastomer tube as air is pumped into the balloon and a voltage is applied through the thickness of the membrane. We formulate the condition for coexistent budged and unbulged sections, and identify allowable states set by electrical breakdown and mechanical rupture. We find that the bulging transition dramatically amplifies electromechanical energy conversion. Energy converted in an electromechanical cycle consisting of unbulged and bulged states is thousands of times that in an electromechanical cycle consisting of only unbulged states.

  20. Design and control of the precise tracking bed based on complex electromechanical design theory

    NASA Astrophysics Data System (ADS)

    Ren, Changzhi; Liu, Zhao; Wu, Liao; Chen, Ken

    2010-05-01

    The precise tracking technology is wide used in astronomical instruments, satellite tracking and aeronautic test bed. However, the precise ultra low speed tracking drive system is one high integrated electromechanical system, which one complexly electromechanical design method is adopted to improve the efficiency, reliability and quality of the system during the design and manufacture circle. The precise Tracking Bed is one ultra-exact, ultra-low speed, high precision and huge inertial instrument, which some kind of mechanism and environment of the ultra low speed is different from general technology. This paper explores the design process based on complex electromechanical optimizing design theory, one non-PID with a CMAC forward feedback control method is used in the servo system of the precise tracking bed and some simulation results are discussed.

  1. Bending-induced electromechanical coupling and large piezoelectric response in a micromachined diaphragm

    PubMed Central

    Wang, Zhihong; Yao, Yingbang; Wang, Xianbin; Yue, Weisheng; Chen, Longqing; Zhang, Xi Xiang

    2013-01-01

    We investigated the dependence of electromechanical coupling and the piezoelectric response of a micromachined Pb(Zr0.52Ti0.48)O3 (PZT) diaphragm on its curvature by observing the impedance spectrum and central deflection responses to a small AC voltage. The curvature of the diaphragm was controlled by applying air pressure to its back. We found that a depolarized flat diaphragm does not initially exhibit electromechanical coupling or the piezoelectric response. However, upon the application of static air pressure to the diaphragm, both electromechanical coupling and the piezoelectric response can be induced in the originally depolarized diaphragm. The piezoelectric response increases as the curvature increases and a giant piezoelectric response can be obtained from a bent diaphragm. The obtained results clearly demonstrate that a high strain gradient in a diaphragm can polarize a PZT film through a flexoelectric effect, and that the induced piezoelectric response of the diaphragm can be controlled by adjusting its curvature. PMID:24185198

  2. Progressive damage detection using the reusable electromechanical impedance method for metal structures with a possibility of weight loss identification

    NASA Astrophysics Data System (ADS)

    Na, Wongi S.

    2016-05-01

    Damage accumulation in structures may result in a structural failure which is a serious problem when ensuring public safety. Although various non-destructive techniques are available to seek for the existence of damage at an early stage, most of these techniques rely on the experience of the experts. To date, automated structural health monitoring systems have been extensively researched and one of the methods, known as the electromechanical impedance (EMI) method, has shown promising results. However, the EMI method is a local method requiring a large number of sensors for covering large areas such as in bridges and buildings. In addition, attaching these sensors onto a surface can be time consuming since adhesives are used for attaching the sensors where its curing time increases the setting up time even further. In this study, the performance of the reusable piezoelectric (PZT) device for metal structures is examined against two different types of progressive damage scenarios. Overall, the reusable PZT device shown in this study has successfully identified damage with a possibility of weight loss detection.

  3. An electromechanical actuation system for an expendable launch vehicle

    NASA Technical Reports Server (NTRS)

    Burrows, Linda M.; Roth, Mary Ellen

    1992-01-01

    A major effort at the NASA Lewis Research Center in recent years has been to develop electro-mechanical actuators (EMA's) to replace the hydraulic systems used for thrust vector control (TVC) on launch vehicles. This is an attempt ot overcome the inherent inefficiencies and costs associated with the existing hydraulic structures. General Dynamics Space Systems Division, under contract to NASA Lewis, is developing 18.6 kW (25 hp), 29.8 kW (40 hp), and 52.2 kW (70 hp) peak EMA systems to meet the power demands for TVC on a family of vehicles developed for the National Launch System. These systems utilize a pulse population modulated converter and field-oriented control scheme to obtain independent control of both the voltage and frequency. These techniques allow an induction motor to be operated at its maximum torque at all times. At NASA Lewis, we are building on this technology to develop our own in-house system capable of meeting the peak power requirements for an expendable launch vehicle (ELV) such as the Atlas. Our EMA will be capable of delivering 22.4 kW (30 hp) peak power with a nominal of 6.0 kW (8 hp). This system differs from the previous ones in two areas: (1) the use of advanced control methods, and (2) the incorporation of built-in-test. The advanced controls are essential for minimizing the controller size, while the built-in-test is necessary to enhance the system reliability and vehicle health monitoring. The ultimate goal of this program is to demonstrate an EMA which will be capable of self-test and easy integration into other projects. This paper will describe the effort underway at NASA Lewis to develop an EMA for an Atlas class ELV. An explanation will be given for each major technology block, and the status of each major technology block and the status of the overall program will be reported.

  4. Electromechanical characterization of carbon nanotubes grown on carbon fiber

    NASA Astrophysics Data System (ADS)

    Patton, Steven T.; Zhang, Qiuhong; Qu, Liangti; Dai, Liming; Voevodin, Andrey A.; Baur, Jeff

    2009-11-01

    Mechanical and electrical properties of carbon fiber (CF) and vertically aligned carbon nanotubes (CNTs) have been thoroughly investigated in previous studies. Growth of radially aligned CNTs on silicon oxide (SiO2) coated CF has recently been accomplished resulting in multiscale composite fiber (CNT/SiO2/CF). CNT/SiO2/CF offers promise as stress and strain sensors in CF reinforced composite materials. However, to date there have been no investigations of the electromechanical properties of CNT/SiO2/CF that would facilitate their usage as sensors in composite materials, which is the focus of this research. This study investigates fundamental mechanical and electrical properties of CF, SiO2/CF (SiO2 coated CF), and CNT/SiO2/CF during localized transverse compression at low loads (μN to mN) and small displacements (nm to a few μms). Force, strain, stiffness, and electrical resistance were monitored simultaneously during compression experiments. For CF, resistance decreased sharply upon compressive loading with hysteresis in both force and resistance being observed at low strain. For SiO2/CF, high resistance and negligible electrical conduction occurred, and the force-displacement curve was linear. CNT/SiO2/CF stiffness increased as force and strain increased and became comparable to that of CF at high strain (˜30%). Hysteresis in both force-displacement and resistance-displacement curves was observed with CNT/SiO2/CF, but was more evident as maximum strain increased and did not depend on strain rate. Force was higher and resistance was lower during compression as compared to decompression. Hysteretic energy loss is associated with internal friction between entangled CNTs. Van der Waals force between deformed and entangled CNTs hindered disentanglement, which reduced the number of electrical current paths and increased resistance during decompression. The results of this study provide new understanding of the mechanical and electrical behavior of CNT/SiO2/CF that

  5. Noncontact photo-acoustic defect detection in drug tablets.

    PubMed

    Varghese, Ivin; Cetinkaya, Cetin

    2007-08-01

    Quality assurance monitoring is of great importance in the pharmaceutical industry for the reason that if defects such as coating layer irregularities, internal cracks, and delamination are present in a drug tablet, the desired dose delivery and bioavailability can be compromised. The U.S. Food and Drug Administration (FDA) established the Process Analytical Technology (PAT) initiative, in order to ensure efficient quality monitoring at each stage of the manufacturing process by the integration of analysis systems into the evaluation procedure. Improving consistency and predictability of tablet action by improving quality and uniformity of tablet coatings as well as ensuring core integrity is required. An ideal technique for quality monitoring would be noninvasive, nondestructive, have a short measurement time, intrinsically safe, and relatively inexpensive. In the proposed acoustic system, a pulsed laser is utilized to generate noncontact mechanical excitations and interferometric detection of transient vibrations of the drug tablets is employed for sensing. Two novel methods to excite vibrational modes in drug tablets are developed and employed: (i) a vibration plate excited by a pulsed-laser and (ii) pulsed laser-induced plasma generated shockwave expansion. Damage in coat and/or core of a tablet weakens its mechanical stiffness and, consequently, affects its acoustic response to an external dynamic force field. From the analysis of frequency spectra and the time-frequency spectrograms obtained under both mechanisms, it can be concluded that defective tablets can be effectively differentiated from the defect-free ones and the proposed proof-of-concept techniques have potential to provide a technology platform to be used in the greater PAT effort.

  6. Non-contact method for characterization of a rotational table

    NASA Astrophysics Data System (ADS)

    La Moure Shattuck, Judson, III; Parisi, Vincent M.; Smerdon, Arryn J.

    2007-04-01

    The United States Air Force (USAF) uses and evaluates a variety of helmet-mounted trackers for incorporation into their high performance aircraft. The primary head tracker technologies commercially available are magnetic trackers, inertial trackers, and optical trackers. Each head tracker has a unique method of determining the pilot's head position within the cockpit of the aircraft. Magnetic trackers generally have a small head mounted size and minimal head weight. Because they sense a generated magnetic field, their accuracy can be affected by other magnetic fields or ferrous components within the cockpit. Inertial trackers cover the entire head motion box but require constant motion in order to accommodate drifting of the inertial sensors or a secondary system that updates the inertial system, often referred to as a hybrid system. Although optical head trackers (OHT) are immune to magnetic fields some of their limitations may be daylight/night vision goggle (NVG) compatibility issues and, depending on system configuration, may require numerous emitters and/or receivers to cover a large head motion box and provide a wide field of regard. The Dynamic Tracker Test Fixture (DTTF) was designed by the Helmet Mounted Sensory Technology (HMST) laboratory to accurately measure azimuth rotation in both static and dynamic conditions for the purpose of determining the accuracy of a variety of head trackers. Before the DTTF could be used as an evaluation tool, it required characterization to determine the amount and location of any induced elevation or roll as the table rotated in azimuth. Optimally, the characterization method would not affect the DTTF's movement so a non-contact method was devised. This paper describes the characterization process and its results.

  7. Microgravity noncontact temperature requirements at NASA Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Santoro, G.

    1989-01-01

    NASA Lewis Research Center is currently supporting 66 microgravity science and applications projects. The 66 projects are separated into 23 flight projects and 43 ground-based projects. The part of the NASA Lewis program dealing with flight experiments is divided into six areas: Combustion Science, Materials Science, Fluid Physics, Instrumentation/Equipment, Advanced Technology Development, and Space Station Multi-User Facility studies. The part of the NASA Lewis program dealing with ground-based experiments is coincidentally also divided into six areas: Electronic Materials, Combustion Science, Fluid Dynamics and Transport Phenomena, Metals and Alloys, Glasses and Ceramics, and Physics and Chemistry Experiments. Several purposes exist for ground-based experimenting. Preliminary information is necessary before a decision can be made for flight status, the short low gravity durations available in ground facilities are adequate for a particular study, or extensive ground-based research must be conducted to define and support the microgravity science endeavors contemplated for space. Not all of the 66 microgravity science and application projects at NASA Lewis have temperature requirements, but most do. Since space allocation does not permit a review of all the pertinent projects, a decision was made to restrict the coverage to the science flight projects, flight projects minus the advanced technology development, and multiuser facility efforts. Very little is lost by this decision as the types of temperature requirements for science flight projects can be considered representative of those for the ground-based projects. The noncontact temperature needs at NASA Lewis, as represented by the science flight projects are discussed by describing briefly the experiments themselves, by displaying an illustration of each experimental setup, and by specifying their temperature requisites.

  8. Development of an electromagnetic acoustic transducer (EMAT) for the noncontact excitation of guided ultrasonic waves

    NASA Astrophysics Data System (ADS)

    Fromme, P.

    2015-03-01

    Fatigue damage can develop in aerospace structures at locations of stress concentration, such as fasteners. For the safe operation of the aircraft fatigue cracks need to be detected before reaching a critical length. Guided ultrasonic waves offer an efficient method for the detection and characterization of such defects in large aerospace structures. Noncontact excitation of guided waves was achieved using electromagnetic acoustic transducers (EMAT). The transducer development for the specific excitation of the A0 Lamb wave mode is explained. The radial and angular dependency of the excited guided wave pulses at different frequencies were measured using a noncontact laser interferometer. Based on the induced eddy currents in the plate a theoretical model was developed and reasonably good agreement with the measured transducer performance was achieved. The developed transducers were employed for defect detection in aluminum components using fully noncontact guided wave measurements. Excitation of the A0 Lamb wave mode was achieved using the developed EMAT transducer and the guided wave propagation and scattering was measured using a noncontact laser interferometer. These results provide the basis for the defect characterization in aerospace structures using noncontact guided wave sensors.

  9. A quantitative analysis of signal reproduction from cylinder recordings measured via noncontact full surface mapping.

    PubMed

    Nascè, Antony; Hill, Martyn; McBride, John W; Boltryk, Peter J

    2008-10-01

    Sound reproduction via a noncontact surface mapping technique has great potential for sound archives, aiming to digitize content from early sound recordings such as wax cylinders, which may otherwise be "unplayable" with a stylus. If the noncontact techniques are to be considered a viable solution for sound archivists, a method for quantifying the quality of the reproduced signal needs to be developed. In this study, a specially produced test cylinder recording, encoded with sinusoids, provides the basis for the first quantitative analysis of signal reproduction from the noncontact full surface mapping method. The sampling and resolution of the measurement system are considered with respect to the requirements for digital archiving of cylinder recordings. Two different methods of audio signal estimation from a discrete groove cross section are described and rated in terms of signal-to-noise ratio and total harmonic distortion. Noncontact and stylus methods of sound reproduction are then compared using the same test cylinder. It is shown that noncontact methods appear to have distinct advantages over stylus reproduction, in terms of reduced harmonic distortion and lower frequency modulation. PMID:19062844

  10. Investigations of the contact bounce behaviors and relative dynamic welding phenomena for electromechanical relay

    NASA Astrophysics Data System (ADS)

    Ren, Wanbin; He, Yuan; Jin, Jianbing; Man, Sida

    2016-06-01

    Dynamic welding, being the principal mechanism of sticking failure, correlates closely with the contact bounce of electromechanical relay. The typical waveforms of dynamic contact force and contact voltage at making and breaking process are obtained with the use of a new designed test rig. The variations in bounce time, bounce numbers, last bounce duration, and relevant welding force are investigated in the electrical endurance test. It is determined that the welding strength and the welding probability are increased with the reduced stationary force. The degradation physical mechanism is present to better understand the relationship between dynamic welding and operation characteristics of electromechanical relay.

  11. Wide-band idler generation in a GaAs electromechanical resonator

    NASA Astrophysics Data System (ADS)

    Mahboob, I.; Wilmart, Q.; Nishiguchi, K.; Fujiwara, A.; Yamaguchi, H.

    2011-09-01

    Periodically modulating the piezoelectrically introduced strain in an electromechanical resonator can enable the fundamental (ω0) and the first modes (ω1) to be coupled. This is explicitly demonstrated with the creation of a mechanical idler at ω1 (ω0) when a signal excitation is applied at ω0 (ω1) and a pump excitation is applied at ω0+ω1. The dynamics of the mechanical idler generation are captured by a simple phenomenological model and our experimental demonstration paves the way toward accessing the diverse functionality of nonlinear optics in an on-chip electromechanical platform.

  12. Enhanced electromechanical coupling of a nanomechanical resonator to coupled superconducting cavities

    PubMed Central

    Li, Peng-Bo; Li, Hong-Rong; Li, Fu-Li

    2016-01-01

    We investigate the electromechanical coupling between a nanomechanical resonator and two parametrically coupled superconducting coplanar waveguide cavities that are driven by a two-mode squeezed microwave source. We show that, with the selective coupling of the resonator to the cavity Bogoliubov modes, the radiation-pressure type coupling can be greatly enhanced by several orders of magnitude, enabling the single photon strong coupling to be reached. This allows the investigation of a number of interesting phenomena such as photon blockade effects and the generation of nonclassical quantum states with electromechanical systems. PMID:26753744

  13. Investigations of the contact bounce behaviors and relative dynamic welding phenomena for electromechanical relay.

    PubMed

    Ren, Wanbin; He, Yuan; Jin, Jianbing; Man, Sida

    2016-06-01

    Dynamic welding, being the principal mechanism of sticking failure, correlates closely with the contact bounce of electromechanical relay. The typical waveforms of dynamic contact force and contact voltage at making and breaking process are obtained with the use of a new designed test rig. The variations in bounce time, bounce numbers, last bounce duration, and relevant welding force are investigated in the electrical endurance test. It is determined that the welding strength and the welding probability are increased with the reduced stationary force. The degradation physical mechanism is present to better understand the relationship between dynamic welding and operation characteristics of electromechanical relay. PMID:27370500

  14. Modulation of stimulated emission of ZnO nanowire based on electromechanical vibration.

    PubMed

    Li, Lijie

    2016-07-01

    An optical modulator is proposed using a double-clamped nanoelectromechanical resonator. Electromechanical-optical analysis has been performed to validate the idea. The electromechanical simulation involves the nonlocal effect as the resonator is in nanometer scale. Stimulated emission theory has been used to model the luminescence of the nanowire due to the addition of piezoelectric charges subjected to mechanical strains. Results successfully demonstrate both the intensity modulation and frequency filtering, providing an integrated solution in applications such as quantum entanglement experiments. PMID:27409201

  15. Nonlinear capacitance dilatometry for investigating elastic and electromechanical properties of ferroelectrets

    SciTech Connect

    Bauer-Gogonea, S.; Camacho-Gonzalez, F.; Schwoediauer, R.; Ploss, B.; Bauer, S.

    2007-09-17

    Nonlinearities in ferroelectret polymer foam capacitors arise from voltage-dependent thickness changes. Such thickness changes are caused by the converse piezoelectric and electrostrictive effects in these soft materials. The authors show that the higher harmonics of the current response during application of a sinusoidal voltage to ferroelectret capacitors provide information on the elastic and electromechanical properties of the foam. The authors demonstrate the potential of this versatile measurement technique by investigating the temperature dependence of the piezoelectric response and by monitoring the changes in the elastic and electromechanical properties during inflation of cellular polypropylene.

  16. Nonlinear capacitance dilatometry for investigating elastic and electromechanical properties of ferroelectrets

    NASA Astrophysics Data System (ADS)

    Bauer-Gogonea, S.; Camacho-Gonzalez, F.; Schwödiauer, R.; Ploss, B.; Bauer, S.

    2007-09-01

    Nonlinearities in ferroelectret polymer foam capacitors arise from voltage-dependent thickness changes. Such thickness changes are caused by the converse piezoelectric and electrostrictive effects in these soft materials. The authors show that the higher harmonics of the current response during application of a sinusoidal voltage to ferroelectret capacitors provide information on the elastic and electromechanical properties of the foam. The authors demonstrate the potential of this versatile measurement technique by investigating the temperature dependence of the piezoelectric response and by monitoring the changes in the elastic and electromechanical properties during inflation of cellular polypropylene.

  17. Electromechanical properties of stripe-electroded tangentially polarized piezoelectric flexural bars.

    PubMed

    Sarangapani, Sairajan; Brown, David A

    2013-05-01

    Piezoelectric bar transducers are commonly used for generating low frequency flexural mode vibrations. The paper calculates the electromechanical properties including the effective electromechanical coupling coefficient of the stripe-electroded tangentially polarized bar transducer vibrating in flexure under the simply supported boundary condition. A numerical analysis is used to model the curved electric field lines. Calculations take into account the internal energies due to the contributions of the transverse and longitudinal piezoelectric effects and the modal strain distribution in the bar. Results are presented as functions of distance between the electrodes and thickness of elements and are compared with traditional bimorph designs employing either transverse or longitudinal polarization.

  18. On the eigenvalue control of electromechanical oscillations by adaptive power system stabilizer

    SciTech Connect

    Ostojic, D.; Kovacevie, B. . Elektrotehnicki Fakultet)

    1990-11-01

    This paper presents the eigenvalue control strategy which utilizes an adaptive power system stabilizer for the decentralized control of damping and frequency of electromechanical oscillations in power systems. The control procedure includes the complete identification of the decoupled subsystem model in real-time from local measurements only and the assignment of its estimated electromechanical eigenvalue by the change of stabilizer parameters. The robustness and efficiency of the proposed adaptive controller to enhance overall system stability are illustrated in several examples, including the three-machine power system model.

  19. Electromechanically generating electricity with a gapped-graphene electric generator

    NASA Astrophysics Data System (ADS)

    Dressen, Donald; Golovchenko, Jene

    2015-03-01

    We demonstrate the fabrication and operation of a gapped-graphene electric generator (G-GEG) device. The G-GEG generates electricity from the mechanical oscillation of droplets of electrolytes and ionic liquids. The spontaneous adsorption of ionic species on graphene charges opposing electric double-layer capacitors (EDLCs) on each half of the device. Modulating the area of contact between the droplet and graphene leads to adsorption/desorption of ions, effectively charging/discharging each EDLC and generating a current. The flow of current supports a potential difference across the G-GEG due to the device's internal impedance. Both the magnitude and polarity of the induced current and voltage show a strong dependence on the type of ionic species used, suggesting that certain ions interact more strongly with graphene than others. We find that a simple model circuit consisting of an AC current source in series with a resistor and a time-varying capacitor accurately predicts the device's dynamic behavior. Additionally, we discuss the effect of graphene's intrinsic quantum capacitance on the G-GEG's performance and speculate on the utility of the device in the context of energy harvesting.

  20. Calibration of non-contact ultrasound as an online sensor for wood characterization: Effects of temperature, moisture, and scanning direction

    NASA Astrophysics Data System (ADS)

    Vun, R. Y.; Hoover, K.; Janowiak, J.; Bhardwaj, M.

    2008-01-01

    Numerous handheld moisture meters are available for measuring moisture levels of wood and building materials for a vast range of quality control and moisture diagnosis applications. However, many methods currently available require physical contact of a probe with the test material to operate. The contact requirement of such devices has limited applications for these purposes. There is a tremendous demand for dynamic online quality assessment of in-process materials for moisture content (MC) measurements. In this paper, a non-destructive non-contact ultrasound technology was used to evaluate the effects of increasing temperature in two MC levels and of increasing MC in lumber. The results show that the ultrasonic absolute transmittance and velocity parameters are directly correlated very well (R2≥0.87) with temperature for the two moisture levels in wood. At constant temperature, however, the velocity is inversely correlated with MC. It was also found that the distribution of MC along the length is marginally insignificant to both ultrasonic measurements. The transmittance measurement along the orthogonal thickness direction is insignificant above the fiber saturation MC; similarly, the velocity measurement is marginally insignificant. The study concludes a positive correlation and a good fit for this technology to advance into the development of an automated device for determining wood moisture levels, which will in turn be used to control the dynamics of wood drying/sterilization processes. Further calibration research is recommended to ascertain the constraints and limitations of the technology to specific wood species and dimension.