The operational principle and the lumped parameters model of capacitive micro-accelerometer are introduced. The equivalent stiffness of different directions of the accelerometer is given. From the point of view of ene...The operational principle and the lumped parameters model of capacitive micro-accelerometer are introduced. The equivalent stiffness of different directions of the accelerometer is given. From the point of view of energy and mechanics, expressions of some key parameters, such as the damping, sensitivity, resolution of the accelerometer, are derived. The accelerometer noise behavior of mechanical-thermal noise in the open-loop system, along with the dynamic range of the open-loop system and closed-loop system is analyzed. The result is that the noise of the capacitive micro accelerometer is dominated by the magnitude of mechanical-thermal noise. At the same time, the magnitude of mechanical-thermal noise depends on the temperature and magnitude of mechanical damp. The result of the measurement from the implemented closed-loop microo-accelerometer system shows that the resolution is the level of rag, and the measurement range is from -50g to 50g.展开更多
Resonant tunnelling diodes （RTDs） have negative differential resistance effect, and the current-voltage characteristics change as a function of external stress, which is regarded as mesc-piezoresistance effect of RT...Resonant tunnelling diodes （RTDs） have negative differential resistance effect, and the current-voltage characteristics change as a function of external stress, which is regarded as mesc-piezoresistance effect of RTDs. In this paper, a novel micro-accelerometer based on AlAs/GaAs/In0.1Ga0.9As/GaAs/AlAs RTDs is designed and fabricated to be a four-beam-mass structure, and an RTD-Wheatstone bridge measurement system is established to test the basic properties of this novel accelerometer. According to the experimental results, the sensitivity of the RTD based micro-accelerometer is adjustable within a range of 3 orders when the bias voltage of the sensor changes. The largest sensitivity of this RTD based miero-accelerometer is 560.2025 mV/g which is about 10 times larger than that of silicon based micro piezoresistive accelerometer, while the smallest one is 1.49135 mV/g.展开更多
A vertically movable gate field effect transistor(VMGFET) is proposed and demonstrated for a microaccelerometer application. The VMGFET using air gap as an insulator layer allows the gate to move on the substrate vert...A vertically movable gate field effect transistor(VMGFET) is proposed and demonstrated for a microaccelerometer application. The VMGFET using air gap as an insulator layer allows the gate to move on the substrate vertically by external forces. Finite element analysis is used to simulate mechanical behaviors of the designed structure. For the simulation, the ground acceleration spectrum of the 1952 Kern County Earthquake is employed to investigate the structural integrity of the sensor in vibration. Based on the simulation, a prototype VMGFET accelerometer is fabricated from silicon on insulator wafer. According to current–voltage characteristics of the prototype VMGFET, the threshold voltage is measured to be 2.32 V, which determines the effective charge density and the mutual transconductance of1.545910-8C cm-2and 6.59 m A V-1, respectively. The device sensitivity is 9.36–9.42 m V g-1in the low frequency,and the first natural frequency is found to be 1230 Hz. The profile smoothness of the sensed signal is in 3 d B range up to1 k Hz.展开更多
To achieve a high precision capacitive closed-loop micro-accelerometer,a full differential CMOS based on switched-capacitor circuit was presented in this paper as the sensor interface circuit.This circuit consists of ...To achieve a high precision capacitive closed-loop micro-accelerometer,a full differential CMOS based on switched-capacitor circuit was presented in this paper as the sensor interface circuit.This circuit consists of a balance-bridge module,a charge sensitive amplifier,a correlated-double-sampling module,and a logic timing control module.A special two-path feedback circuit configuration was given to improve the system linearity.The quantitative analysis of error voltage and noise shows that there is tradeoff around circuit's noise,speed and accuracy.A detailed design method was given for this tradeoff.The noise performance optimized circuit has a noise root spectral density of 1.0 μV/Hz,equivalent to rms noise root spectral density of 1.63 μg/Hz.Therefore,the sensor's Brown noise becomes the main noise source in this design.This circuit is designed with 0.5 μm n-well CMOS process.Under a ±5 V supply,the Hspice simulation shows that the system sensitivity achieves 0.616 V/g,the system offset is as low as 1.456 mV,the non-linearity is below 0.03%,and the system linear range achieves ±5 g.展开更多
The wetting phenomenon of composite substrates in hypergravitational environment has a huge application in electronic devices and astronaut healthcare in aerospace missions.In the present contribution,the governing eq...The wetting phenomenon of composite substrates in hypergravitational environment has a huge application in electronic devices and astronaut healthcare in aerospace missions.In the present contribution,the governing equation of high-G droplets on the composite substrate is firstly established in the hypergravitational environment.Meanwhile,the apparent contact angles at the contact line between droplets and substrates with different stiffness gradients are achieved.Then,we analyze the effects of hypergravity factor and the substrate stiffness on the wetting profile of high-G droplets.By introducing the droplet volume and contact angle into the Bond number,the scaling law of the high-G droplet profile is established,and we find that the contact radius of the droplet R/S^(0.5)has a linear relationship withρω^(2)rl^(2)S/(γ_(LV)^(θ)),while the droplet height H/S^(0.5)has a power-law relationship withρω^(2)rl^(2)S/(γ_(LV)^(θ)).Finally,we explain the profiles of high-G droplets during the wetting process by illustrating energy components of the entire system and find that the substrate with positive triangular stiffness and inverted triangular stiffness show opposite evolution laws.On a substrate with inverted triangular stiffness,the gravitational potential energy is more dominant.展开更多
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
The behavior of resistance high-g impact of EMC （epoxy molding compound） with two package models, small outline package （POS） and Globtop, was evaluated by experimental method used Hopkinson bar. At 120,000 g （ge...The behavior of resistance high-g impact of EMC （epoxy molding compound） with two package models, small outline package （POS） and Globtop, was evaluated by experimental method used Hopkinson bar. At 120,000 g （generated in the Hopkinson bar with widths about 70 μs） no damage in either the POS devices or the Globtop devices was observed. In order to enhance the EMC＇s ability of resistance high-g impact, buffering effect of epoxy resin was also studied. The experimental results above all show that EMC has a better performance of impact resistance at about 120,000 g, and epoxy resin can absorb the stress wave to have the protected ability. The study of this paper could serve as a basis for selection packaging materials and enhance its reliability in high-g impact environment.展开更多
This paper designs a wireless sensor network based on CC2530.The sensor nodes consist of multi-ranged accelerometer and CC2530,covering all the ranges of the acceleration signals which can be measured.The designed sys...This paper designs a wireless sensor network based on CC2530.The sensor nodes consist of multi-ranged accelerometer and CC2530,covering all the ranges of the acceleration signals which can be measured.The designed system solves the problems such as cable installation trouble of testing system,vulnerability to interference and complexity of circuit.Test results show that the designed wireless sensor network can transmit the signals that multi-ranged micro-accelerometer emits without spoilage,thus the measurement of acceleration of the covering region is completed.展开更多
A handwriting detecting system based on Micro- accelerometer and Micro-gyros is proposed. And the algorithm of the detecting system is also described in detail. And the error analysis of the detecting system is also d...A handwriting detecting system based on Micro- accelerometer and Micro-gyros is proposed. And the algorithm of the detecting system is also described in detail. And the error analysis of the detecting system is also described in de-tail. The motion contrail of the handwriting de-tecting in the 3-D space can be recognized through compute the matrix of attitude angles and the dynamic information of the handwriting detecting which is mapped on the 2-D plane. Then the information of contrail can be recurred on the writing plane by integral. There were good results in the actual experiment.展开更多
The hard target smart fuse of penetration ammunition is developing to be smaller, lighter, smarter and multifunction. After analyzing the characteristics of high-g accelerating signals and the penetration algorithms, ...The hard target smart fuse of penetration ammunition is developing to be smaller, lighter, smarter and multifunction. After analyzing the characteristics of high-g accelerating signals and the penetration algorithms, this paper provides a solution of penetration ammunition fuse system based on embedded technology. This fuse system realizes acquisition of the high-g accelerating signals and uses the appropriate penetration algorithms to process them. The fuse system can not only make the same type of penetration ammunition to attack different kinds of objects accurately, but also meet the other requirements of the function of penetration ammunition fuse system.展开更多
Driven by“More than Moore”,miniaturization and multifunctional integration of micro-energy devices are emerging as critical pathways for next-generation compact microsystems.This study proposes a sensing-in-Energy(S...Driven by“More than Moore”,miniaturization and multifunctional integration of micro-energy devices are emerging as critical pathways for next-generation compact microsystems.This study proposes a sensing-in-Energy(SiE)microdevice that immerses an inertial switch in a parallel-connected supercapacitor’s electrolyte,enabling simultaneous impact sensing and stable energy supply under extremely high gravitational acceleration(high-g)shocks(over 10,000 g).The SiE microdevice can be viewed as a high-amplitude shock sensor(raw signal peak>50 mV)under high-frequency perspective,and a shock-resistant electrochemical power source(voltage fluctuation<2%)under low-frequency perspective,while energy consumption reduces over 99.9%compared with conventional high-g sensor due to its event-driven mechanism.Sensing performance is boosted>50%using multiphysics model combined with machine learning algorithm.Furthermore,a fuze microsystem was built based on SiE microdevice,achieving 150μs-level ultrafast response.Three-layer penetration experiments have verified the engineering application of SiE microdevice and its fuze microsystem in smart munitions domains,providing a novel paradigm for heterogeneous microsystem in high-dynamic environments.展开更多
In this study, the discharge voltage behavior of electric double-layer capacitors （EDLCs） during high-g impact is studied both theoretically and experimentally. A micro-scale dynamic mechanism is proposed to describ...In this study, the discharge voltage behavior of electric double-layer capacitors （EDLCs） during high-g impact is studied both theoretically and experimentally. A micro-scale dynamic mechanism is proposed to describe the physical basis of the increase in the discharge voltage during a high-g impact. Based on this dynamic mechanism, a multi-field model is established, and the simulation and experimental studies of the discharge voltage increase phenomenon are conducted. From the simulation and experimental data, the relationship between the increased voltage and the high-g acceleration is revealed. An acceleration detection range of up to 10,000g is verified. The design of the device is optimized by studying the influences of the parameters, such as the electrode thickness and discharge current, on the outputs. This work opens up new avenues for the development of autonomous sensor systems based on energy storage devices and is significant for many practical applications such as in collision testing and automobile safety.展开更多
文摘The operational principle and the lumped parameters model of capacitive micro-accelerometer are introduced. The equivalent stiffness of different directions of the accelerometer is given. From the point of view of energy and mechanics, expressions of some key parameters, such as the damping, sensitivity, resolution of the accelerometer, are derived. The accelerometer noise behavior of mechanical-thermal noise in the open-loop system, along with the dynamic range of the open-loop system and closed-loop system is analyzed. The result is that the noise of the capacitive micro accelerometer is dominated by the magnitude of mechanical-thermal noise. At the same time, the magnitude of mechanical-thermal noise depends on the temperature and magnitude of mechanical damp. The result of the measurement from the implemented closed-loop microo-accelerometer system shows that the resolution is the level of rag, and the measurement range is from -50g to 50g.
基金supported in part by the National Natural Science Foundation of China (Grant No 50775209)the Fork Ying Tung Education Foundation (Grant No 101052)Program for Excellent Talents by Ministry of Education of China
文摘Resonant tunnelling diodes （RTDs） have negative differential resistance effect, and the current-voltage characteristics change as a function of external stress, which is regarded as mesc-piezoresistance effect of RTDs. In this paper, a novel micro-accelerometer based on AlAs/GaAs/In0.1Ga0.9As/GaAs/AlAs RTDs is designed and fabricated to be a four-beam-mass structure, and an RTD-Wheatstone bridge measurement system is established to test the basic properties of this novel accelerometer. According to the experimental results, the sensitivity of the RTD based micro-accelerometer is adjustable within a range of 3 orders when the bias voltage of the sensor changes. The largest sensitivity of this RTD based miero-accelerometer is 560.2025 mV/g which is about 10 times larger than that of silicon based micro piezoresistive accelerometer, while the smallest one is 1.49135 mV/g.
基金supported by the National Research Foundation of Korea(NRF)funded by the Korea government(MSIP)(No.2012M2A8A5025825)
文摘A vertically movable gate field effect transistor(VMGFET) is proposed and demonstrated for a microaccelerometer application. The VMGFET using air gap as an insulator layer allows the gate to move on the substrate vertically by external forces. Finite element analysis is used to simulate mechanical behaviors of the designed structure. For the simulation, the ground acceleration spectrum of the 1952 Kern County Earthquake is employed to investigate the structural integrity of the sensor in vibration. Based on the simulation, a prototype VMGFET accelerometer is fabricated from silicon on insulator wafer. According to current–voltage characteristics of the prototype VMGFET, the threshold voltage is measured to be 2.32 V, which determines the effective charge density and the mutual transconductance of1.545910-8C cm-2and 6.59 m A V-1, respectively. The device sensitivity is 9.36–9.42 m V g-1in the low frequency,and the first natural frequency is found to be 1230 Hz. The profile smoothness of the sensed signal is in 3 d B range up to1 k Hz.
基金Sponsored by the National High Technology Research and Development Program of China(863Program)(Grant No.2008AA042201)
文摘To achieve a high precision capacitive closed-loop micro-accelerometer,a full differential CMOS based on switched-capacitor circuit was presented in this paper as the sensor interface circuit.This circuit consists of a balance-bridge module,a charge sensitive amplifier,a correlated-double-sampling module,and a logic timing control module.A special two-path feedback circuit configuration was given to improve the system linearity.The quantitative analysis of error voltage and noise shows that there is tradeoff around circuit's noise,speed and accuracy.A detailed design method was given for this tradeoff.The noise performance optimized circuit has a noise root spectral density of 1.0 μV/Hz,equivalent to rms noise root spectral density of 1.63 μg/Hz.Therefore,the sensor's Brown noise becomes the main noise source in this design.This circuit is designed with 0.5 μm n-well CMOS process.Under a ±5 V supply,the Hspice simulation shows that the system sensitivity achieves 0.616 V/g,the system offset is as low as 1.456 mV,the non-linearity is below 0.03%,and the system linear range achieves ±5 g.
基金supported by the National Natural Science Foundation of China(Grant Nos.12322206,12272340,and 11925206)Basic Science Center Program for Multiphase Media Evolution in Hypergravity of the National Natural Science Foundation of China(Grant No.51988101)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LD21A020002).
文摘The wetting phenomenon of composite substrates in hypergravitational environment has a huge application in electronic devices and astronaut healthcare in aerospace missions.In the present contribution,the governing equation of high-G droplets on the composite substrate is firstly established in the hypergravitational environment.Meanwhile,the apparent contact angles at the contact line between droplets and substrates with different stiffness gradients are achieved.Then,we analyze the effects of hypergravity factor and the substrate stiffness on the wetting profile of high-G droplets.By introducing the droplet volume and contact angle into the Bond number,the scaling law of the high-G droplet profile is established,and we find that the contact radius of the droplet R/S^(0.5)has a linear relationship withρω^(2)rl^(2)S/(γ_(LV)^(θ)),while the droplet height H/S^(0.5)has a power-law relationship withρω^(2)rl^(2)S/(γ_(LV)^(θ)).Finally,we explain the profiles of high-G droplets during the wetting process by illustrating energy components of the entire system and find that the substrate with positive triangular stiffness and inverted triangular stiffness show opposite evolution laws.On a substrate with inverted triangular stiffness,the gravitational potential energy is more dominant.
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.
基金Funded by the State Key Laboratory Foundation of China (No.9140C120704060C12)the Science and Technology Development Project of Universiti-esin of Shanxi Province
文摘The behavior of resistance high-g impact of EMC （epoxy molding compound） with two package models, small outline package （POS） and Globtop, was evaluated by experimental method used Hopkinson bar. At 120,000 g （generated in the Hopkinson bar with widths about 70 μs） no damage in either the POS devices or the Globtop devices was observed. In order to enhance the EMC＇s ability of resistance high-g impact, buffering effect of epoxy resin was also studied. The experimental results above all show that EMC has a better performance of impact resistance at about 120,000 g, and epoxy resin can absorb the stress wave to have the protected ability. The study of this paper could serve as a basis for selection packaging materials and enhance its reliability in high-g impact environment.
基金National Natural Science Foundation of China(No.51075374)
文摘This paper designs a wireless sensor network based on CC2530.The sensor nodes consist of multi-ranged accelerometer and CC2530,covering all the ranges of the acceleration signals which can be measured.The designed system solves the problems such as cable installation trouble of testing system,vulnerability to interference and complexity of circuit.Test results show that the designed wireless sensor network can transmit the signals that multi-ranged micro-accelerometer emits without spoilage,thus the measurement of acceleration of the covering region is completed.
文摘A handwriting detecting system based on Micro- accelerometer and Micro-gyros is proposed. And the algorithm of the detecting system is also described in detail. And the error analysis of the detecting system is also described in de-tail. The motion contrail of the handwriting de-tecting in the 3-D space can be recognized through compute the matrix of attitude angles and the dynamic information of the handwriting detecting which is mapped on the 2-D plane. Then the information of contrail can be recurred on the writing plane by integral. There were good results in the actual experiment.
文摘The hard target smart fuse of penetration ammunition is developing to be smaller, lighter, smarter and multifunction. After analyzing the characteristics of high-g accelerating signals and the penetration algorithms, this paper provides a solution of penetration ammunition fuse system based on embedded technology. This fuse system realizes acquisition of the high-g accelerating signals and uses the appropriate penetration algorithms to process them. The fuse system can not only make the same type of penetration ammunition to attack different kinds of objects accurately, but also meet the other requirements of the function of penetration ammunition fuse system.
基金granted by the Young Elite Scientists Sponsorship Program of CAST(No.2023QNRC001)the National Key Research and Development Program of China(No.2023YFB3211205).
文摘Driven by“More than Moore”,miniaturization and multifunctional integration of micro-energy devices are emerging as critical pathways for next-generation compact microsystems.This study proposes a sensing-in-Energy(SiE)microdevice that immerses an inertial switch in a parallel-connected supercapacitor’s electrolyte,enabling simultaneous impact sensing and stable energy supply under extremely high gravitational acceleration(high-g)shocks(over 10,000 g).The SiE microdevice can be viewed as a high-amplitude shock sensor(raw signal peak>50 mV)under high-frequency perspective,and a shock-resistant electrochemical power source(voltage fluctuation<2%)under low-frequency perspective,while energy consumption reduces over 99.9%compared with conventional high-g sensor due to its event-driven mechanism.Sensing performance is boosted>50%using multiphysics model combined with machine learning algorithm.Furthermore,a fuze microsystem was built based on SiE microdevice,achieving 150μs-level ultrafast response.Three-layer penetration experiments have verified the engineering application of SiE microdevice and its fuze microsystem in smart munitions domains,providing a novel paradigm for heterogeneous microsystem in high-dynamic environments.
文摘In this study, the discharge voltage behavior of electric double-layer capacitors （EDLCs） during high-g impact is studied both theoretically and experimentally. A micro-scale dynamic mechanism is proposed to describe the physical basis of the increase in the discharge voltage during a high-g impact. Based on this dynamic mechanism, a multi-field model is established, and the simulation and experimental studies of the discharge voltage increase phenomenon are conducted. From the simulation and experimental data, the relationship between the increased voltage and the high-g acceleration is revealed. An acceleration detection range of up to 10,000g is verified. The design of the device is optimized by studying the influences of the parameters, such as the electrode thickness and discharge current, on the outputs. This work opens up new avenues for the development of autonomous sensor systems based on energy storage devices and is significant for many practical applications such as in collision testing and automobile safety.
