A triaxial high-g accelerometer of microelectro mechanical systems （MEMS） has a struc- ture of multi-chips combination and will be used in aerospace field, civil and military fields. The ac- celerometer can measure ...A triaxial high-g accelerometer of microelectro mechanical systems （MEMS） has a struc- ture of multi-chips combination and will be used in aerospace field, civil and military fields. The ac- celerometer can measure the acceleration of the carrier. The chips with island-membrane structures on its back surfaces are made by MEMS dry processing. The chip is reasonable and can work well under high impact load; Titanium alloy base is also stronger in high shock environment, these are proved by finite element analysis. Finally, the MEMS combined triaxial high-g accelerometer is vali- dated by high impact calibration experiments in order to get a key performance index, including range, sensitivity and transverse sensitivity and so on. These data can satisfy the need of design but some problems remain, these will be eliminated by improvement of the processing technology and materials.展开更多
A piezoresistive silicon accelerometer fabricated by a selective,self-stopping porous silicon (PS) etching method using an epitaxial layer for movable microstructures is described and analyzed.The technique is capable...A piezoresistive silicon accelerometer fabricated by a selective,self-stopping porous silicon (PS) etching method using an epitaxial layer for movable microstructures is described and analyzed.The technique is capable of constructing a microstructure precisely.PS is used as a sacrificial layer,and releasing holes are etched in the film.TMAH solution with additional Si powder and (NH_4)_2S_2O_8 is used to remove PS through the small releasing holes without eroding uncovered Al.The designed fabrication process is full compatible with standard CMOS process.展开更多
The property of silicon micro-capacitive accelerometer is analyzed and discussed by establishing the model of the sensor,to lay a basis for optimization design of sensor system structure. Discussed issues include the ...The property of silicon micro-capacitive accelerometer is analyzed and discussed by establishing the model of the sensor,to lay a basis for optimization design of sensor system structure. Discussed issues include the static modeling and dynamic behavior of the two commonly used structures,i.e., double-cantilever supported and four-beam supported structures, and also the measurement range of these devices.展开更多
A single-loop fourth-order sigma-delta（ΣΔ） interface circuit for a closed-loop micromachined accelerometer is presented.Two additional electronic integrators are cascaded with the micromachined sensing element to ...A single-loop fourth-order sigma-delta（ΣΔ） interface circuit for a closed-loop micromachined accelerometer is presented.Two additional electronic integrators are cascaded with the micromachined sensing element to form a fourth-order loop filter.The three main noise sources affecting the overall system resolution of aΣΔaccelerometer, mechanical noise,electronic noise and quantization noise,are analyzed in detail.Accurate mathematical formulas for electronic and quantization noise are established.The ASIC is fabricated in a 0.5μm two-metal two-poly n-well CMOS process.The test results indicate that the mechanical noise and electronic noise are 1μg/（Hz）^（1/2） and 8μV/（Hz）^（1/2） respectively,and the theoretical models of electronic and quantization noise agree well with the test and simulation results.展开更多
This paper presents the design principles and fabrication techniques for simultaneously forming non-coplanar resonant beams and crab-leg supporting beams of dual-axis bulk micromachined resonant accelerometers by mask...This paper presents the design principles and fabrication techniques for simultaneously forming non-coplanar resonant beams and crab-leg supporting beams of dual-axis bulk micromachined resonant accelerometers by masked-maskless combined anisotropic etching.Four resonant beams are located at the surface of a silicon substrate,whereas the gravity centre of a proof mass lies within the neutral plane of four crab-leg supporting beams on the same substrate.Compared with early reported mechanical structures,the simple structure not only eliminates the bending moments caused by in-plane acceleration,and thereby avoiding the rotation of the proof mass,but also providing sufficiently small rigidity to X and Y axes accelerations,potentially leading to a large sensitivity for measuring the in-plane acceleration.展开更多
This study proposes a novel design and micromachining process for a dual-cantilever accelerometer.Comb and curved-surface structures are integrated into the sensing structure to modulate the squeeze-film damping,thus ...This study proposes a novel design and micromachining process for a dual-cantilever accelerometer.Comb and curved-surface structures are integrated into the sensing structure to modulate the squeeze-film damping,thus effectively optimizing the response frequency bandwidth.Owing to the high stress concentration on the dual-cantilever integrated with a fully sensitive piezoresistive Wheatstone bridge,a high sensitivity to acceleration is achieved.In addition,the dual-cantilever accelerometer is fabricated using a specifically developed low-cost and high-yield(111)-silicon single-side bulk-micromachining process.The test results show that the proposed dualcantilever accelerometer exhibits a sensitivity of 0.086—0.088 mV/g/3.3 V and a nonlinearity of±(0.09%—0.23%)FS(full-scale).Based on dynamic characterization,an adequate frequency bandwidth of 2.64 kHz is verified.Furthermore,a resonant frequency of 4.388 kHz is measured,and a low quality factor(Q)of 7.62 is obtained,which agrees well with the design for air-damping modulation.The achieved high performance renders the proposed dual-cantilever accelerometer promising in applications such as automotive and consumer electronics.展开更多
基金Supported by the National Natural Science Foundation of China(61273346)the National Defense Major Fundamental Research Program of China(20110003)+3 种基金the National Defense Key Fundamental Research Program of China(20132010)Specialized Research Fund for the Doctoral Program of Higher Education(20121101120009)Excellent Young Scholars Research Fund of Beijing Institute of Technology(2012YG0203)the Program for the Fundamental Research of Beijing Institute of Technology(2015CX02034)
文摘A triaxial high-g accelerometer of microelectro mechanical systems （MEMS） has a struc- ture of multi-chips combination and will be used in aerospace field, civil and military fields. The ac- celerometer can measure the acceleration of the carrier. The chips with island-membrane structures on its back surfaces are made by MEMS dry processing. The chip is reasonable and can work well under high impact load; Titanium alloy base is also stronger in high shock environment, these are proved by finite element analysis. Finally, the MEMS combined triaxial high-g accelerometer is vali- dated by high impact calibration experiments in order to get a key performance index, including range, sensitivity and transverse sensitivity and so on. These data can satisfy the need of design but some problems remain, these will be eliminated by improvement of the processing technology and materials.
文摘A piezoresistive silicon accelerometer fabricated by a selective,self-stopping porous silicon (PS) etching method using an epitaxial layer for movable microstructures is described and analyzed.The technique is capable of constructing a microstructure precisely.PS is used as a sacrificial layer,and releasing holes are etched in the film.TMAH solution with additional Si powder and (NH_4)_2S_2O_8 is used to remove PS through the small releasing holes without eroding uncovered Al.The designed fabrication process is full compatible with standard CMOS process.
文摘The property of silicon micro-capacitive accelerometer is analyzed and discussed by establishing the model of the sensor,to lay a basis for optimization design of sensor system structure. Discussed issues include the static modeling and dynamic behavior of the two commonly used structures,i.e., double-cantilever supported and four-beam supported structures, and also the measurement range of these devices.
基金supported by the National High Technology Research and Development Program of China(No.2008AA042201).
文摘A single-loop fourth-order sigma-delta（ΣΔ） interface circuit for a closed-loop micromachined accelerometer is presented.Two additional electronic integrators are cascaded with the micromachined sensing element to form a fourth-order loop filter.The three main noise sources affecting the overall system resolution of aΣΔaccelerometer, mechanical noise,electronic noise and quantization noise,are analyzed in detail.Accurate mathematical formulas for electronic and quantization noise are established.The ASIC is fabricated in a 0.5μm two-metal two-poly n-well CMOS process.The test results indicate that the mechanical noise and electronic noise are 1μg/（Hz）^（1/2） and 8μV/（Hz）^（1/2） respectively,and the theoretical models of electronic and quantization noise agree well with the test and simulation results.
基金Project (No. 61076110) supported by the National Natural Science Foundation of China
文摘This paper presents the design principles and fabrication techniques for simultaneously forming non-coplanar resonant beams and crab-leg supporting beams of dual-axis bulk micromachined resonant accelerometers by masked-maskless combined anisotropic etching.Four resonant beams are located at the surface of a silicon substrate,whereas the gravity centre of a proof mass lies within the neutral plane of four crab-leg supporting beams on the same substrate.Compared with early reported mechanical structures,the simple structure not only eliminates the bending moments caused by in-plane acceleration,and thereby avoiding the rotation of the proof mass,but also providing sufficiently small rigidity to X and Y axes accelerations,potentially leading to a large sensitivity for measuring the in-plane acceleration.
基金National Key R&D Program of China(Nos.2016YFA0200800 and 2016YFA0200803)National Natural Science Foundation of China(Nos.61674160 and 61834007)。
文摘This study proposes a novel design and micromachining process for a dual-cantilever accelerometer.Comb and curved-surface structures are integrated into the sensing structure to modulate the squeeze-film damping,thus effectively optimizing the response frequency bandwidth.Owing to the high stress concentration on the dual-cantilever integrated with a fully sensitive piezoresistive Wheatstone bridge,a high sensitivity to acceleration is achieved.In addition,the dual-cantilever accelerometer is fabricated using a specifically developed low-cost and high-yield(111)-silicon single-side bulk-micromachining process.The test results show that the proposed dualcantilever accelerometer exhibits a sensitivity of 0.086—0.088 mV/g/3.3 V and a nonlinearity of±(0.09%—0.23%)FS(full-scale).Based on dynamic characterization,an adequate frequency bandwidth of 2.64 kHz is verified.Furthermore,a resonant frequency of 4.388 kHz is measured,and a low quality factor(Q)of 7.62 is obtained,which agrees well with the design for air-damping modulation.The achieved high performance renders the proposed dual-cantilever accelerometer promising in applications such as automotive and consumer electronics.
