The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Yuelin Wang - One of the best experts on this subject based on the ideXlab platform.
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a novel sandwich capacitive accelerometer with a double sided 16 Beam Mass structure
Microelectronic Engineering, 2014Co-Authors: Wei Li, Xiaolin Li, Zhaohui Song, Yuelin WangAbstract:A novel sandwich capacitive accelerometer with a double-sided, 16-Beam-Mass structure is presented. In this design, the proof Mass is supported by 16 tiny Beams distributed uniformly on both sides, which aims to dramatically reduce the cross-axis response. Parameters of the Beam-Mass structure are analyzed and optimized by analytical modeling and the finite element analysis (FEA) method. The micro-accelerometer is fabricated by bulk micromachining technology, and the proof Mass and tiny Beams are released by KOH anisotropic wet etching from both sides of the silicon wafer, simultaneously. The resonance frequency and the quality factor of the accelerometer are 4.34kHz and 311, respectively, which are measured in an open-loop system. The measurement results show that the accelerometer has a full-scale (FS) range of 30g, a close-loop sensitivity of 80mV/g, and a nonlinearity of 0.27% of FS. The cross-axis sensitivities are 0.353% (x/z axis) and 0.045% (y/z axis), respectively. The bias stability is 0.63mg for an hour. The accelerometer can withstand high shock of over 10,000g.
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Fabrication of a MEMS capacitive accelerometer with symmetrical double-sided serpentine Beam-Mass structure
Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems, 2013Co-Authors: Xiaofeng Zhou, Xiaolin Li, Jian Wu, Yuelin WangAbstract:This paper presents a symmetrical double-sided serpentine Beam-Mass structure design with a convenient and precise process of manufacturing MEMS accelerometers. The symmetrical double-sided serpentine Beam-Mass structure is fabricated from a single double-device-layer SOI wafer, which has identical buried oxides and device layers on both sides of a thick handle layer. The fabrication process produced proof Mass with though wafer thickness (860 μm) to enable formation of a larger proof Mass. Two layers of single crystal silicon serpentine Beams with highly controllable dimension suspend the proof Mass from both sides. A sandwich differential capacitive accelerometer based on symmetrical double-sided serpentine Beams-Mass structure is fabricated by three layer silicon/silicon wafer direct bonding. The resonance frequency of the accelerometer is measured in open loop system by a network analyzer. The quality factor and the resonant frequency are 14 and 724 Hz, respectively. The differential capacitance sensitivity of the fabricated accelerometer is 15 pF/g. The sensitivity of the device with close loop interface circuit is 2 V/g, and the nonlinearity is 0.6 % over the range of 0–1 g. The measured input referred noise floor of accelerometer with interface circuit is 2 μg/√Hz (0–250 Hz).
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a novel capacitive accelerometer with a highly symmetrical double sided Beam Mass structure
Sensors and Actuators A-physical, 2012Co-Authors: Xiaofeng Zhou, Bin Xiong, Xiaolin Li, Jian Wu, Yuelin WangAbstract:This paper reports a novel capacitive accelerometer with highly symmetrical double-sided Beam-Mass structure. The highly symmetrical structure is fabricated from single wafer by a novel vertical sidewall protection technique. The good device performance i
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single wafer fabrication of a symmetric double sided Beam Mass structure using drie and wet etching by a novel vertical sidewall protection technique
Journal of Micromechanics and Microengineering, 2010Co-Authors: Xiaofeng Zhou, Bin Xiong, Yuelin Wang, Zuankai WangAbstract:A symmetric double-sided Beam–Mass structure is of interest for the design of novel MEMS sensors and actuators. Conventional methods to achieve symmetric Beam–Mass structures have been heavily dependent on bonding or heavy boron doping, which is costly or can notoriously lead to undesirable residual stress as well. In this paper, we report on a novel vertical sidewall protection technique to fabricate symmetric double-sided Beam–Mass structures (also Beams) at a single-wafer level without the need for bonding or doping-based etching, by cleverly taking advantage of the fact that self-stop etching will occur at {1 1 1} planes. Moreover, the thickness of the Beams is only determined by the depth of dry etching (deep reactive ion etching, DRIE), which excludes the strict dependence on wafer thickness and precise etching time control. We believe that this simple yet powerful technique would open an avenue to fabricate symmetric double-sided structures for various applications.
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A new symmetrical Beam-Mass structure for accelerometers by anisotropic etching without convex corner compensation
2008 3rd IEEE International Conference on Nano Micro Engineered and Molecular Systems, 2008Co-Authors: Fei Xiao, Bin Xiong, Yuelin WangAbstract:This paper reports a new symmetrical Beam-Mass structure for sandwich capacitive accelerometers. The single-wafer fabrication of the symmetrical double-sided Beam-Mass structure in which eight straight Beams are connected to the corners of the proof Mass is accomplished only by anisotropic wet etching of a (100) wafer without convex corner compensation. Different measuring-range accelerometers can be got by controlling the thickness of the spring Beam. A packaged sensor with 140 mum Beam thickness is measured by a dropping hammer system. The sensitivity is 58 muV/g for a 5000 g shock acceleration under 5 V power supply.
P Ziemann - One of the best experts on this subject based on the ideXlab platform.
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chemical analysis of diesel engine nanoparticles using a nano dma thermal desorption particle Beam Mass spectrometer
Environmental Science & Technology, 2001Co-Authors: Herbert J Tobias, Peter H. Mcmurry, P Ziemann, Derek E Beving, Hiromu Sakurai, Darrick D Zarling, Robert Waytulonis, David B. KittelsonAbstract:Diesel engines are known to emit high number concentrations of nanoparticles (diameter < 50 nm), but the physical and chemical mechanisms by which they form are not understood. Information on chemical composition is lacking because the small size, low Mass concentration, and potential for contamination of samples obtained by standard techniques make nanoparticles difficult to analyze. A nano-differential mobility analyzer was used to size-select nanoparticles (Mass median diameter ∼25−60 nm) from diesel engine exhaust for subsequent chemical analysis by thermal desorption particle Beam Mass spectrometry. Mass spectra were used to identify and quantify nanoparticle components, and compound molecular weights and vapor pressures were estimated from calibrated desorption temperatures. Branched alkanes and alkyl-substituted cycloalkanes from unburned fuel and/or lubricating oil appear to contribute most of the diesel nanoparticle Mass. The volatility of the organic fraction of the aerosol increases as the engi...
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real time chemical analysis of organic aerosols using a thermal desorption particle Beam Mass spectrometer
Aerosol Science and Technology, 2000Co-Authors: Herbert J Tobias, Peter M Kooiman, Kenneth S Docherty, P ZiemannAbstract:An instrument has been developed for real-time, quantitative chemical analys is of organic particles in laboratory environments. In this apparatus, which we call a Thermal Desorption Particle Beam Mass Spectrometer (TDPBMS), particles are sampled into a differentially-pumped vacuum chamber, focused into a narrow, low-divergence particle Beam using aerodynamic lenses, and then transported into a high-vacuum region where they impact on a heated surface, evaporate, and the vapor is Mass analyzed in a quadrupole Mass spectrometer. The average composition of a continuous stream of particles is thus measured in real time, and size-dependent composition can be obtained by passing the incoming aerosol through a differential mobility analyzer. The TDPBMS can analyze multi component organic particles in the 0.02-0.5mu m size range for compound concentrations 0.1-1mu g m3 without particle matrix effects. By using careful calibration techniques that account for particle shape and transport efficiency, the particulate...
Xiaofeng Zhou - One of the best experts on this subject based on the ideXlab platform.
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Fabrication of a MEMS capacitive accelerometer with symmetrical double-sided serpentine Beam-Mass structure
Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems, 2013Co-Authors: Xiaofeng Zhou, Xiaolin Li, Jian Wu, Yuelin WangAbstract:This paper presents a symmetrical double-sided serpentine Beam-Mass structure design with a convenient and precise process of manufacturing MEMS accelerometers. The symmetrical double-sided serpentine Beam-Mass structure is fabricated from a single double-device-layer SOI wafer, which has identical buried oxides and device layers on both sides of a thick handle layer. The fabrication process produced proof Mass with though wafer thickness (860 μm) to enable formation of a larger proof Mass. Two layers of single crystal silicon serpentine Beams with highly controllable dimension suspend the proof Mass from both sides. A sandwich differential capacitive accelerometer based on symmetrical double-sided serpentine Beams-Mass structure is fabricated by three layer silicon/silicon wafer direct bonding. The resonance frequency of the accelerometer is measured in open loop system by a network analyzer. The quality factor and the resonant frequency are 14 and 724 Hz, respectively. The differential capacitance sensitivity of the fabricated accelerometer is 15 pF/g. The sensitivity of the device with close loop interface circuit is 2 V/g, and the nonlinearity is 0.6 % over the range of 0–1 g. The measured input referred noise floor of accelerometer with interface circuit is 2 μg/√Hz (0–250 Hz).
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a novel capacitive accelerometer with a highly symmetrical double sided Beam Mass structure
Sensors and Actuators A-physical, 2012Co-Authors: Xiaofeng Zhou, Bin Xiong, Xiaolin Li, Jian Wu, Yuelin WangAbstract:This paper reports a novel capacitive accelerometer with highly symmetrical double-sided Beam-Mass structure. The highly symmetrical structure is fabricated from single wafer by a novel vertical sidewall protection technique. The good device performance i
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single wafer fabrication of a symmetric double sided Beam Mass structure using drie and wet etching by a novel vertical sidewall protection technique
Journal of Micromechanics and Microengineering, 2010Co-Authors: Xiaofeng Zhou, Bin Xiong, Yuelin Wang, Zuankai WangAbstract:A symmetric double-sided Beam–Mass structure is of interest for the design of novel MEMS sensors and actuators. Conventional methods to achieve symmetric Beam–Mass structures have been heavily dependent on bonding or heavy boron doping, which is costly or can notoriously lead to undesirable residual stress as well. In this paper, we report on a novel vertical sidewall protection technique to fabricate symmetric double-sided Beam–Mass structures (also Beams) at a single-wafer level without the need for bonding or doping-based etching, by cleverly taking advantage of the fact that self-stop etching will occur at {1 1 1} planes. Moreover, the thickness of the Beams is only determined by the depth of dry etching (deep reactive ion etching, DRIE), which excludes the strict dependence on wafer thickness and precise etching time control. We believe that this simple yet powerful technique would open an avenue to fabricate symmetric double-sided structures for various applications.
Michael R. Zachariah - One of the best experts on this subject based on the ideXlab platform.
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Molecular Beam Mass Spectrometry System for Characterization of Thermal Plasma Chemical Vapor Deposition
Plasma Chemistry and Plasma Processing, 2004Co-Authors: Soonam Park, Feng Liao, John M. Larson, Steven L. Girshick, Michael R. ZachariahAbstract:A molecular Beam Mass spectrometry system for in situ measurement of the concentration of gas phase species including radicals impinging on a substrate during thermal plasma chemical vapor deposition (TPCVD) has been designed and constructed. Dynamically controlled substrate temperature was achieved using a variable thermal contact resistance method via a backside flow of an argon/helium mixture. A high quality molecular Beam with Beam‐to‐background signal greater than 20 was obtained under film growth conditions by sampling through a small nozzle (75 μm) in the center of the substrate. Mass discrimination effects were accounted for in order to quantify the species measurements. We demonstrate that this system has a minimum detection limit of under 100 ppb. Quantitative measurements of hydrocarbon species (H, H_2, C, CH_3, CH_4, C_2H_2, C_2H_4) using Ar/H_2/CH_4 mixtures and silicon species (Si, SiH, SiH_2, SiCl, SiCl_2, Cl, HCl) using Ar/H_2/SiCl_4 mixtures were obtained under thermal plasma chemical vapor deposition conditions.
Herbert J Tobias - One of the best experts on this subject based on the ideXlab platform.
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chemical analysis of diesel engine nanoparticles using a nano dma thermal desorption particle Beam Mass spectrometer
Environmental Science & Technology, 2001Co-Authors: Herbert J Tobias, Peter H. Mcmurry, P Ziemann, Derek E Beving, Hiromu Sakurai, Darrick D Zarling, Robert Waytulonis, David B. KittelsonAbstract:Diesel engines are known to emit high number concentrations of nanoparticles (diameter < 50 nm), but the physical and chemical mechanisms by which they form are not understood. Information on chemical composition is lacking because the small size, low Mass concentration, and potential for contamination of samples obtained by standard techniques make nanoparticles difficult to analyze. A nano-differential mobility analyzer was used to size-select nanoparticles (Mass median diameter ∼25−60 nm) from diesel engine exhaust for subsequent chemical analysis by thermal desorption particle Beam Mass spectrometry. Mass spectra were used to identify and quantify nanoparticle components, and compound molecular weights and vapor pressures were estimated from calibrated desorption temperatures. Branched alkanes and alkyl-substituted cycloalkanes from unburned fuel and/or lubricating oil appear to contribute most of the diesel nanoparticle Mass. The volatility of the organic fraction of the aerosol increases as the engi...
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real time chemical analysis of organic aerosols using a thermal desorption particle Beam Mass spectrometer
Aerosol Science and Technology, 2000Co-Authors: Herbert J Tobias, Peter M Kooiman, Kenneth S Docherty, P ZiemannAbstract:An instrument has been developed for real-time, quantitative chemical analys is of organic particles in laboratory environments. In this apparatus, which we call a Thermal Desorption Particle Beam Mass Spectrometer (TDPBMS), particles are sampled into a differentially-pumped vacuum chamber, focused into a narrow, low-divergence particle Beam using aerodynamic lenses, and then transported into a high-vacuum region where they impact on a heated surface, evaporate, and the vapor is Mass analyzed in a quadrupole Mass spectrometer. The average composition of a continuous stream of particles is thus measured in real time, and size-dependent composition can be obtained by passing the incoming aerosol through a differential mobility analyzer. The TDPBMS can analyze multi component organic particles in the 0.02-0.5mu m size range for compound concentrations 0.1-1mu g m3 without particle matrix effects. By using careful calibration techniques that account for particle shape and transport efficiency, the particulate...
