Electrical equivalent modeling of MEMS differential capacitive accelerometer

Abstract The paper presents an electrical equivalent model of Micro-Electro-Mechanical Systems (MEMS) differential capacitive accelerometer. The accelerometer structure is symmetrically suspended using folded beam springs. An electrical equivalent circuit is proposed for the mechanical structure using Force-Current analogy. Electrical circuit model of squeeze air film damping is also taken into account. The simulation results of temperature and pressure variations on the accelerometer for both mechanical and electrical domains are analyzed and compared using MATLAB®, and the results for both the domains are found to be closely matching. The results are compared with the analytical mechanical model of MEMS differential capacitive accelerometer recently reported by Mukhiya et al. (2019) [23]; and are found to be closely matching. The optimum pressure range for operation is found to be 200 ​Pa–300 ​Pa. Settling time is found to be less than 10 ​ms, which also verifies a bandwidth of 100 ​Hz. The proposed model has reasonably good accuracy and requires less computational time in comparison to FEM-based numerical models.

[1]  Yuming Mo,et al.  Squeeze film air damping ratio analysis of a silicon capacitive micromechanical accelerometer , 2018 .

[2]  Janderson R. Rodrigues,et al.  MEMS capacitive accelerometer: dynamic sensitivity analysis based on analytical squeeze film damping and mechanical thermoelasticity approaches , 2019, SN Applied Sciences.

[3]  Min Chen,et al.  Equivalent Electrical Modeling and Simulation of MEMS Comb Accelerometer , 2010, 2010 International Conference on Measuring Technology and Mechatronics Automation.

[4]  A. Burgdorfer.  The Influence of the Molecular Mean Free Path on the Performance of Hydrodynamic Gas Lubricated Bearings , 1959 .

[5]  Robert B. Randall,et al.  Vibration-based Condition Monitoring: Industrial, Aerospace and Automotive Applications , 2011 .

[6]  Farrokh Ayazi,et al.  Micromachined inertial sensors , 1998, Proc. IEEE.

[7]  Jacek Nazdrowicz,et al.  Electrical equivalent model of MEMS accelerometer in Matlab/SIMULINK environment , 2018, 2018 XIV-th International Conference on Perspective Technologies and Methods in MEMS Design (MEMSTECH).

[8]  Blaine Reeder,et al.  Health at hand: A systematic review of smart watch uses for health and wellness , 2016, J. Biomed. Informatics.

[9]  R. Mukhiya,et al.  Design, modelling and system level simulations of DRIE-based MEMS differential capacitive accelerometer , 2019, Microsystem Technologies.

[10]  G M Lyons,et al.  Accelerometers in rehabilitation medicine for older adults. , 2005, Age and ageing.

[11]  Xianshan Dong,et al.  Research on temperature characteristic of parasitic capacitance in MEMS capacitive accelerometer , 2019, Sensors and Actuators A: Physical.

[12]  Minhang Bao,et al.  Squeeze film air damping in MEMS , 2007 .

[13]  S. Senturia.  Microsystem Design , 2000 .

[14]  Katsuyuki Machida,et al.  Evaluation and modeling of adhesion layer in shock-protection structure for MEMS accelerometer , 2016, Microelectron. Reliab..

[15]  P. Dempsey,et al.  The Teardown: Apple Watch , 2015 .

[16]  H. H. Richardson,et al.  A Study of Fluid Squeeze-Film Damping , 1966 .

[17]  Tao Dong,et al.  Integrated micro Pirani gauge based hermetical package monitoring for uncooled VOx bolometer FPAs , 2011 .

[18]  M. K. Andrews,et al.  A resonant pressure sensor based on a squeezed film of gas , 1993 .

[19]  Matthias Gietzelt,et al.  Comparison and validation of capacitive accelerometers for health care applications , 2012, Comput. Methods Programs Biomed..

[20]  Alexander J. Casson,et al.  Gyroscope vs. accelerometer measurements of motion from wrist PPG during physical exercise , 2016, ICT Express.

[21]  Deepak Bansal,et al.  REVIEW OF MEMS TEST STRUCTURES FOR MECHANICAL PARAMETER EXTRACTION , 2011 .

[22]  F. A. Firestone.  A NEW ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS , 1932 .

[23]  M. Madhan,et al.  Study of squeeze film damping characteristics under different gas mediums in a capacitive MEMS accelerometer , 2016 .

[24]  Gang Yang,et al.  A MEMS sandwich differential capacitive silicon-on-insulator accelerometer , 2013 .

[25]  E. Peter Carden,et al.  Vibration Based Condition Monitoring: A Review , 2004 .

[26]  M. K. Andrews,et al.  A comparison of squeeze-film theory with measurements on a microstructure , 1993 .

[27]  Leonardo Pantoli,et al.  Automatic Bridge-based Interface for Differential Capacitive Full Sensing☆ , 2016 .

[28]  T. Veijola,et al.  Equivalent-circuit model of the squeezed gas film in a silicon accelerometer , 1995 .

[29]  Petri Kuosmanen,et al.  Internet of Things Based Monitoring of Large Rotor Vibration With a Microelectromechanical Systems Accelerometer , 2019, IEEE Access.

[30]  Cesar Torres-Huitzil,et al.  Accelerometer-Based Human Activity Recognition in Smartphones for Healthcare Services , 2015 .

[31]  Elisson Rocha,et al.  Accelerometer-Based Human Fall Detection Using Convolutional Neural Networks , 2019, Sensors.

[32]  Timo Veijola,et al.  Equivalent Circuit Models for Micromechanical Inertial Sensors , 1999 .

[33]  M. Rajesh Kumar,et al.  Accelerometer Based Home Automation System Using IoT , 2018, SocProS.

[34]  Paul Dempsey.  The Teardown: Apple MacBook 2015 , 2015 .