This paper provides a brief introduction to the application of the sensor monitoring network of micro-electro-mechanical systems(MEMS)to Zhejiang province.In the Wenzhou Shanxi reservoir and other areas,MEMS and tradi...This paper provides a brief introduction to the application of the sensor monitoring network of micro-electro-mechanical systems(MEMS)to Zhejiang province.In the Wenzhou Shanxi reservoir and other areas,MEMS and traditional intensity-monitoring instruments have been deployed with complementary functions to implement hybrid networking.The low-cost MEMS network can continuously monitor areas at high risk of earthquakes at a high resolution.Moreover,it can quickly collect the parameters of earthquakes and records of the near-field acceleration of strong earthquakes.It can be also used to rapidly generate earthquake intensity reports and provide early warning of earthquakes.We used the MEMS sensors for the first time in 2016,and it has helped promote the development and application of seismic intensity instruments since then.展开更多
In recent years,a large number of small volume,low cost micro electro mechanical systems（MEMS）digital three-axis angular rate gyroscopes have been developed and widely used in civil and military fields.However,these...In recent years,a large number of small volume,low cost micro electro mechanical systems（MEMS）digital three-axis angular rate gyroscopes have been developed and widely used in civil and military fields.However,these kinds of gyroscopes have poor performances in initial zero-bias,temperature drift,In-Run bias stability,bias repeatability,etc.,their output errors need to be compensated before being used.Based on a lot of experiments,the temperature drift and the initial zero-bias are the major error sources in the MEMS gyroscopes output data.Due to the poor repeatability of temperature drift,the temperature compensation coefficients need to be recalculated every time before using.In order to recalculate parameters of the temperature compensation model quickly,a 1st-order polynomial model of temperature is established,then a forgetting factor recursive least squares estimator will be adopted to identify the model parameters in real time.Static and dynamic experimental data shows that this method removed/compensated the temperature drift and initial zero-bias from the output of the gyroscopes effectively.展开更多
The non-linearity problem of aircraft system could not be overcome by using the MEMS sensor only.In order to improve the accuracy of aerial vehicle attitude,an aircraft attitude estimation of the MEMS sensor based on ...The non-linearity problem of aircraft system could not be overcome by using the MEMS sensor only.In order to improve the accuracy of aerial vehicle attitude,an aircraft attitude estimation of the MEMS sensor based on modified particle filter is proposed.The aircraft attitude is optimized by the conjugate gradient method,and the drift error of gyroscope is reduced.Moreover,the particle weight is updated by the observed value to obtain an optimized state estimate.Finally,the conjugate gradient method and the modified particle filter are weightily combined to determine the optimal weighting factor.The attitude estimation is carried out with STM32 and MEMS sensor as the core to design system.The experimental results show that the static and dynamic attitude estimation performances of the aircraft are improved.The performances are well,the attitude data is relatively stable,and the tracking characteristics are better.Moreover,it has better robustness and stability.展开更多
Today,the vast majority of microelectromechanical system(MEMS)sensors are mechanically rigid and therefore suffer from disadvantages when used in intimately wearable or bio-integrated applications.By applying new engi...Today,the vast majority of microelectromechanical system(MEMS)sensors are mechanically rigid and therefore suffer from disadvantages when used in intimately wearable or bio-integrated applications.By applying new engineering strategies,mechanically bendable and stretchable MEMS devices have been successfully demonstrated.This article reviews recent progress in this area,focusing on high-performance flexible devices based on inorganic thin films.We start with the common design and fabrication strategies for flexibility and stretchability,summarize the recent application-oriented flexible devices,and conclude with criteria and opportunities for the future development of flexible MEMS sensors.展开更多
Zeolitic imidazolate frameworks(ZIFs)are a series of materials composited by metal ions and organic ligands with high specific surface area,which might be great precursors to produce metal oxides by calcination for ga...Zeolitic imidazolate frameworks(ZIFs)are a series of materials composited by metal ions and organic ligands with high specific surface area,which might be great precursors to produce metal oxides by calcination for gas sensor application.However,Zn-ZIF(ZIF-8)is hard to transform as ZnO in air and keeping the unique framework simultaneously.In this work,Fe^(2+)was introduced into the metal node to replace a part of Zn^(2+)ions,and it could be oxidized as Fe^(3+)in the calcination to facilitate the oxidation process of the 2-methylimdazole ligands to give Fe-ZnO complex shell with high specific surface area(108 m~2/g)and abundant oxygen vacancies(48%).The micro electro mechanical systems(MEMS)sensor based on the6%-Fe-ZnO complex shell performed outstanding gas sensing properties to the low-concentration acetone vapor,including high response(ΔR/R_g=11.2 to 5 ppm acetone),superior selectivity(S_(acetone)/S_(ethanol)=5.6)and fast response speed(τ_(res)=2.6 s).This work not only provided the research of an exceptional acetone MEMS sensor,but also induced a strategy to produce metal oxide derived from ZIFs with complex structures for the universal synthesis methodology.展开更多
A novel instrument named Micro-Electro-Mechanical System(MEMS) flexible hot-film shear stress sensor was used to study the boundary shear stress distribution in the generalized natural meandering open channel, and the...A novel instrument named Micro-Electro-Mechanical System(MEMS) flexible hot-film shear stress sensor was used to study the boundary shear stress distribution in the generalized natural meandering open channel, and the mean sidewall shear stress distribution along the meandering channel, and the lateral boundary shear stress distribution in the typical cross-section of the meandering channel was analysed. Based on the measurement of the boundary shear stress, a semi-empirical semi-theoretical computing approach of the boundary shear stress was derived including the effects of the secondary flow, sidewall roughness factor, eddy viscosity and the additional Reynolds stress, and more importantly, for the first time, it combined the effects of the cross-section central angle and the Reynolds number into the expressions. Afterwards, a comparison between the previous research and this study was developed. Following the result, we found that the semi-empirical semi-theoretical boundary shear stress distribution algorithm can predict the boundary shear stress distribution precisely. Finally, a single factor analysis was conducted on the relationship between the average sidewall shear stress on the convex and concave bank and the flow rate, water depth, slope ratio,or the cross-section central angle of the open channel bend. The functional relationship with each of the above factors was established, and then the distance from the location of the extreme sidewall shear stress to the bottom of the open channel was deduced based on the statistical theory.展开更多
Abstract： This paper presents a charge-sensitive-amplifier （CSA） based readout circuit for capacitive microelectro-mechanical-system （MEMS） sensors. A continuous-time （CT） readout structure using the chopper te...Abstract： This paper presents a charge-sensitive-amplifier （CSA） based readout circuit for capacitive microelectro-mechanical-system （MEMS） sensors. A continuous-time （CT） readout structure using the chopper technique is adopted to cancel the low frequency noise and improve the resolution of the readout circuits. An operational trans-conductance amplifier （OTA） structure with an auxiliary common-mode-feedback-OTA is proposed in the fully differential CSA to suppress the chopper modulation induced disturbance at the OTA input terminal. An analog temperature compensation method is proposed, which adjusts the chopper signal amplitude with temperature variation to compensate the temperature drift of the CSA readout sensitivity. The chip is designed and implemented in a 0.35μm CMOS process and is 2.1 × 2.1 mm2 in area. The measurement shows that the readout circuit achieves 0.9 aF/√H capacitive resolution, 97 dB dynamic range in 100 Hz signal bandwidth, and 0.8 mV/fF sensitivity with a temperature drift of 35 ppm/℃ after optimized compensation.展开更多
A new type of seismic intensity meter based on MEMS accelerometer is introduced. It employs STM32FI07 as the data processing core and detects the changes of acceleration with triaxial MEMS LIS344ALH and uses ADS1248 f...A new type of seismic intensity meter based on MEMS accelerometer is introduced. It employs STM32FI07 as the data processing core and detects the changes of acceleration with triaxial MEMS LIS344ALH and uses ADS1248 for 24 bit data sampling. The test on vibration table shows that the linearity of the meter is δL = ± 1.4% , and the sensitivity is Kc = 0.9671V/g with zero deviation of 0.0043 g. The seismic intensity meter has the advantages of simple structure and stable performance and it is appropriate for intensive layout on a large scale.展开更多
The governing differential equation of micro/nanbeams with atom/molecule adsorption is derived in the presence of surface effects using the nonlocal elasticity. The effects of the nonlocal parameter, the adsorption de...The governing differential equation of micro/nanbeams with atom/molecule adsorption is derived in the presence of surface effects using the nonlocal elasticity. The effects of the nonlocal parameter, the adsorption density, and the surface parameter on the resonant frequency of the micro/nanobeams are investigated. It is found that, in ad- dition to the nonlocal parameter and the surface parameter, the bending rigidity and the adsorption-induced mass exhibit different behaviors with the increase in the adsorption density depending on the adatom category and the substrate material.展开更多
Doped lead-zirconate-titanate(PZT)thin films are preferred for the development of micro-electro-mechanical systems(MEMS)-based acoustic sensors because of their inherent higher dielectric and piezoelectric coefficient...Doped lead-zirconate-titanate(PZT)thin films are preferred for the development of micro-electro-mechanical systems(MEMS)-based acoustic sensors because of their inherent higher dielectric and piezoelectric coefficients.Patterning process is used to develop such MEMS devices which is highly complex even for undoped PZT thin films;therefore,the problem is further cumbersome for doped PZT thin films due to the presence of added dopant elements and their associated chemistry.This paper presents patterning of strontium(Sr)and lanthanum(La)co-doped PZT thin film(PSLZT)deposited on platinized silicon substrate using wet and dry etching processes for fabricating a diaphragm structure with thickness of 15-25μm and diameter of 1.4-2 mm,suitable for acoustic sensing applications.The effects of various etching conditions have been studied and the results are reported.It is found that the dry etching is the most suited process for realizing the piezoelectric MEMS structure due to its higher etching resolution.An appreciable etching rate of 260-270 nm/min with smooth vertical sidewalls is achieved.The silicon diaphragm with patterned PSLZT thin film is found to retain more than 80%of its dielectric and piezoelectric coefficients and has a resonance of 1.43 MHz.展开更多
The purpose of this study is two-fold： firstly, the development of a cheap, easy-to-construct and effective nanoparticle generator for testing nanoparticle sensors; secondly, the use of such a generator to test the e...The purpose of this study is two-fold： firstly, the development of a cheap, easy-to-construct and effective nanoparticle generator for testing nanoparticle sensors; secondly, the use of such a generator to test the effectiveness of a sensor device in trapping aerosolised nanoparticles. In this study, we have constructed an effective aerosol generator platform, based on aerosol-assisted chemical vapour deposition technology. Under well-controlled experimental conditions, this platform is capable of depositing aerosolised sodium chloride particles homogeneously on a substrate very effectively. Deposited aerosol droplets were subsequently dried and shown to form nanosized cubic crystals that are free from impurities. This platform was employed to test the effectiveness of a MEMS comb device in the electrostatic trapping of nanoparticles. Upon applying a DC bias （0.5 V） to the MEMS device, results showed an increase in nanoparticle deposition on the surface of the device, due to electrostatic precipitation. The presence of an electric field was shown to affect crystal formation upon drying of the aerosol droplets on the substrate; this caused a blotchy appearance on the SEM image, which was not observed in the absence of electric field.展开更多
Two types of 5μm thick hybrid orientation structure wafers,which were integrated by（110）or（100） orientation silicon wafers as the substrate,have been investigated for 15-40 V voltage ICs and MEMS sensor applicati...Two types of 5μm thick hybrid orientation structure wafers,which were integrated by（110）or（100） orientation silicon wafers as the substrate,have been investigated for 15-40 V voltage ICs and MEMS sensor applications.They have been obtained mainly by SOI wafer bonding and a non-selective epitaxy technique,and have been presented in China for the first time.The thickness of BOX SiO2 buried in wafer is 220 nm.It has been found that the quality of hybrid orientation structure with（100）wafer substrate is better than that with（110）wafer substrate by＂Sirtl defect etching of HOSW＂.展开更多
文摘This paper provides a brief introduction to the application of the sensor monitoring network of micro-electro-mechanical systems(MEMS)to Zhejiang province.In the Wenzhou Shanxi reservoir and other areas,MEMS and traditional intensity-monitoring instruments have been deployed with complementary functions to implement hybrid networking.The low-cost MEMS network can continuously monitor areas at high risk of earthquakes at a high resolution.Moreover,it can quickly collect the parameters of earthquakes and records of the near-field acceleration of strong earthquakes.It can be also used to rapidly generate earthquake intensity reports and provide early warning of earthquakes.We used the MEMS sensors for the first time in 2016,and it has helped promote the development and application of seismic intensity instruments since then.
文摘In recent years,a large number of small volume,low cost micro electro mechanical systems（MEMS）digital three-axis angular rate gyroscopes have been developed and widely used in civil and military fields.However,these kinds of gyroscopes have poor performances in initial zero-bias,temperature drift,In-Run bias stability,bias repeatability,etc.,their output errors need to be compensated before being used.Based on a lot of experiments,the temperature drift and the initial zero-bias are the major error sources in the MEMS gyroscopes output data.Due to the poor repeatability of temperature drift,the temperature compensation coefficients need to be recalculated every time before using.In order to recalculate parameters of the temperature compensation model quickly,a 1st-order polynomial model of temperature is established,then a forgetting factor recursive least squares estimator will be adopted to identify the model parameters in real time.Static and dynamic experimental data shows that this method removed/compensated the temperature drift and initial zero-bias from the output of the gyroscopes effectively.
基金National Natural Science Foundation of China(No.61261029)
文摘The non-linearity problem of aircraft system could not be overcome by using the MEMS sensor only.In order to improve the accuracy of aerial vehicle attitude,an aircraft attitude estimation of the MEMS sensor based on modified particle filter is proposed.The aircraft attitude is optimized by the conjugate gradient method,and the drift error of gyroscope is reduced.Moreover,the particle weight is updated by the observed value to obtain an optimized state estimate.Finally,the conjugate gradient method and the modified particle filter are weightily combined to determine the optimal weighting factor.The attitude estimation is carried out with STM32 and MEMS sensor as the core to design system.The experimental results show that the static and dynamic attitude estimation performances of the aircraft are improved.The performances are well,the attitude data is relatively stable,and the tracking characteristics are better.Moreover,it has better robustness and stability.
基金the National Natural Science Foundation of China(No.62001322)the Tianjin Municipal Science and Technology Project(No.20JCQNJC011200)+1 种基金the National Key Research and Development Program of China(No.2020YFB2008801)the Nanchang Institute for Microtechnology of Tianjin University.
文摘Today,the vast majority of microelectromechanical system(MEMS)sensors are mechanically rigid and therefore suffer from disadvantages when used in intimately wearable or bio-integrated applications.By applying new engineering strategies,mechanically bendable and stretchable MEMS devices have been successfully demonstrated.This article reviews recent progress in this area,focusing on high-performance flexible devices based on inorganic thin films.We start with the common design and fabrication strategies for flexibility and stretchability,summarize the recent application-oriented flexible devices,and conclude with criteria and opportunities for the future development of flexible MEMS sensors.
基金supported by the National Natural Science Foundation of China(No.62271299)Shanghai Engineering Research Center for Integrated Circuits and Advanced Display Materials。
文摘Zeolitic imidazolate frameworks(ZIFs)are a series of materials composited by metal ions and organic ligands with high specific surface area,which might be great precursors to produce metal oxides by calcination for gas sensor application.However,Zn-ZIF(ZIF-8)is hard to transform as ZnO in air and keeping the unique framework simultaneously.In this work,Fe^(2+)was introduced into the metal node to replace a part of Zn^(2+)ions,and it could be oxidized as Fe^(3+)in the calcination to facilitate the oxidation process of the 2-methylimdazole ligands to give Fe-ZnO complex shell with high specific surface area(108 m~2/g)and abundant oxygen vacancies(48%).The micro electro mechanical systems(MEMS)sensor based on the6%-Fe-ZnO complex shell performed outstanding gas sensing properties to the low-concentration acetone vapor,including high response(ΔR/R_g=11.2 to 5 ppm acetone),superior selectivity(S_(acetone)/S_(ethanol)=5.6)and fast response speed(τ_(res)=2.6 s).This work not only provided the research of an exceptional acetone MEMS sensor,but also induced a strategy to produce metal oxide derived from ZIFs with complex structures for the universal synthesis methodology.
基金financially supported by the National Key R&D Program of China(Grant No.2016YFC0402306)the National Natural Science Foundation of China(Grant No.51779149)
文摘A novel instrument named Micro-Electro-Mechanical System(MEMS) flexible hot-film shear stress sensor was used to study the boundary shear stress distribution in the generalized natural meandering open channel, and the mean sidewall shear stress distribution along the meandering channel, and the lateral boundary shear stress distribution in the typical cross-section of the meandering channel was analysed. Based on the measurement of the boundary shear stress, a semi-empirical semi-theoretical computing approach of the boundary shear stress was derived including the effects of the secondary flow, sidewall roughness factor, eddy viscosity and the additional Reynolds stress, and more importantly, for the first time, it combined the effects of the cross-section central angle and the Reynolds number into the expressions. Afterwards, a comparison between the previous research and this study was developed. Following the result, we found that the semi-empirical semi-theoretical boundary shear stress distribution algorithm can predict the boundary shear stress distribution precisely. Finally, a single factor analysis was conducted on the relationship between the average sidewall shear stress on the convex and concave bank and the flow rate, water depth, slope ratio,or the cross-section central angle of the open channel bend. The functional relationship with each of the above factors was established, and then the distance from the location of the extreme sidewall shear stress to the bottom of the open channel was deduced based on the statistical theory.
基金supported by the National Natural Science Foundation of China(No.61106025)the CAS/SAFEA International Partnership Program for Creative Research Teams
文摘Abstract： This paper presents a charge-sensitive-amplifier （CSA） based readout circuit for capacitive microelectro-mechanical-system （MEMS） sensors. A continuous-time （CT） readout structure using the chopper technique is adopted to cancel the low frequency noise and improve the resolution of the readout circuits. An operational trans-conductance amplifier （OTA） structure with an auxiliary common-mode-feedback-OTA is proposed in the fully differential CSA to suppress the chopper modulation induced disturbance at the OTA input terminal. An analog temperature compensation method is proposed, which adjusts the chopper signal amplitude with temperature variation to compensate the temperature drift of the CSA readout sensitivity. The chip is designed and implemented in a 0.35μm CMOS process and is 2.1 × 2.1 mm2 in area. The measurement shows that the readout circuit achieves 0.9 aF/√H capacitive resolution, 97 dB dynamic range in 100 Hz signal bandwidth, and 0.8 mV/fF sensitivity with a temperature drift of 35 ppm/℃ after optimized compensation.
基金supported by the Director of Foundation of the Institute of Seismology,China Earthquake Administration(IS201016030)
文摘A new type of seismic intensity meter based on MEMS accelerometer is introduced. It employs STM32FI07 as the data processing core and detects the changes of acceleration with triaxial MEMS LIS344ALH and uses ADS1248 for 24 bit data sampling. The test on vibration table shows that the linearity of the meter is δL = ± 1.4% , and the sensitivity is Kc = 0.9671V/g with zero deviation of 0.0043 g. The seismic intensity meter has the advantages of simple structure and stable performance and it is appropriate for intensive layout on a large scale.
基金Project supported by the National Basic Research Program of China(No.2011CB610300)the 111 Project of China(No.B07050)+3 种基金the National Natural Science Foundation of China(Nos.10972182, 11172239,and 10902089)the Doctoral Program Foundation of Education Ministry of China (No.20106102110019)the Open Foundation of State Key Laboratory of Structural Analysis of Industrial Equipment of China(No.GZ0802)the Doctorate Foundation of Northwestern Polytechnical University of China(No.CX201111)
文摘The governing differential equation of micro/nanbeams with atom/molecule adsorption is derived in the presence of surface effects using the nonlocal elasticity. The effects of the nonlocal parameter, the adsorption density, and the surface parameter on the resonant frequency of the micro/nanobeams are investigated. It is found that, in ad- dition to the nonlocal parameter and the surface parameter, the bending rigidity and the adsorption-induced mass exhibit different behaviors with the increase in the adsorption density depending on the adatom category and the substrate material.
文摘Doped lead-zirconate-titanate(PZT)thin films are preferred for the development of micro-electro-mechanical systems(MEMS)-based acoustic sensors because of their inherent higher dielectric and piezoelectric coefficients.Patterning process is used to develop such MEMS devices which is highly complex even for undoped PZT thin films;therefore,the problem is further cumbersome for doped PZT thin films due to the presence of added dopant elements and their associated chemistry.This paper presents patterning of strontium(Sr)and lanthanum(La)co-doped PZT thin film(PSLZT)deposited on platinized silicon substrate using wet and dry etching processes for fabricating a diaphragm structure with thickness of 15-25μm and diameter of 1.4-2 mm,suitable for acoustic sensing applications.The effects of various etching conditions have been studied and the results are reported.It is found that the dry etching is the most suited process for realizing the piezoelectric MEMS structure due to its higher etching resolution.An appreciable etching rate of 260-270 nm/min with smooth vertical sidewalls is achieved.The silicon diaphragm with patterned PSLZT thin film is found to retain more than 80%of its dielectric and piezoelectric coefficients and has a resonance of 1.43 MHz.
文摘The purpose of this study is two-fold： firstly, the development of a cheap, easy-to-construct and effective nanoparticle generator for testing nanoparticle sensors; secondly, the use of such a generator to test the effectiveness of a sensor device in trapping aerosolised nanoparticles. In this study, we have constructed an effective aerosol generator platform, based on aerosol-assisted chemical vapour deposition technology. Under well-controlled experimental conditions, this platform is capable of depositing aerosolised sodium chloride particles homogeneously on a substrate very effectively. Deposited aerosol droplets were subsequently dried and shown to form nanosized cubic crystals that are free from impurities. This platform was employed to test the effectiveness of a MEMS comb device in the electrostatic trapping of nanoparticles. Upon applying a DC bias （0.5 V） to the MEMS device, results showed an increase in nanoparticle deposition on the surface of the device, due to electrostatic precipitation. The presence of an electric field was shown to affect crystal formation upon drying of the aerosol droplets on the substrate; this caused a blotchy appearance on the SEM image, which was not observed in the absence of electric field.
基金Project supported by the National Basic Research Program of China(No61398)the National Laboratory of Analog Integrated Circuits Foundation of China(NoYZ0808)
文摘Two types of 5μm thick hybrid orientation structure wafers,which were integrated by（110）or（100） orientation silicon wafers as the substrate,have been investigated for 15-40 V voltage ICs and MEMS sensor applications.They have been obtained mainly by SOI wafer bonding and a non-selective epitaxy technique,and have been presented in China for the first time.The thickness of BOX SiO2 buried in wafer is 220 nm.It has been found that the quality of hybrid orientation structure with（100）wafer substrate is better than that with（110）wafer substrate by＂Sirtl defect etching of HOSW＂.
