A double differential torsional micro-accelerometer based on V-shape beam

Abstract This paper reports the design, simulation, fabrication and measurement of a double differential torsional micro-accelerometer based on V-shape beam. The structure of conventional torsional micro-accelerometers is typically composed of two unbalanced proof masses and a torsional beam. This work develops a torsional micro-accelerometer with an optimized structure, which is composed of four proof masses splitting into two pairs. The two pairs of unbalanced masses have the opposite sensitivity to acceleration but the same sensitivity to off-acceleration input, and by using double differential arithmetic the sensitivity, environment robustness and bias stability can be improved. The accelerometer prototype is fabricated with the pre-buried mask wet-etching method and tested. The resonant frequency and quality factor are about 1485 Hz and 28.02 respectively. The sensitivity and nonlinearity of the measuring range ±15 g is 0.14 mV/g and 0.22% respectively. The x-axis and y-axis cross-axis errors are 0.04% and 0.69% respectively. The 1 g bias stability of the accelerometer is 0.11 mg for 1 h and the Allan deviation is 8.7 μg. In the full temperature range of −40 °C to +60 °C,the temperature sensitivity of the scale factor is 49.9 ppm/°C while the offset temperature coefficient is 0.22 mg/°C after temperature compensation.

[1]  Yi Chiu,et al.  A new process for CMOS MEMS capacitive sensors with high sensitivity and thermal stability , 2011 .

[2]  G. Stemme,et al.  Stress-minimized packaging of inertial sensors using wire bonding , 2013, 2013 Transducers & Eurosensors XXVII: The 17th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS & EUROSENSORS XXVII).

[3]  Guofen Xie,et al.  Process development of an all-silicon capacitive accelerometer with a highly symmetrical spring-mass structure etched in TMAH + Triton-X-100 , 2014 .

[4]  Yilong Hao,et al.  A SOI sandwich differential capacitance accelerometer with low-stress package , 2014, The 9th IEEE International Conference on Nano/Micro Engineered and Molecular Systems (NEMS).

[5]  Hongwei Qu,et al.  Fully differential CMOS-MEMS z-axis accelerometer with torsional structures and planar comb fingers , 2010 .

[6]  Ying-Zong Juang,et al.  Implementation of a monolithic capacitive accelerometer in a wafer-level 0.18 µm CMOS MEMS process , 2012 .

[7]  P. Zwahlen,et al.  Ultra-high precision MEMS accelerometer , 2011, 2011 16th International Solid-State Sensors, Actuators and Microsystems Conference.

[8]  Khalil Najafi,et al.  A Generic Environment-Resistant Packaging Technology for MEMS , 2007, TRANSDUCERS 2007 - 2007 International Solid-State Sensors, Actuators and Microsystems Conference.

[9]  Anthony S. Kourepenis,et al.  Micromechanical silicon instrument and systems development at Draper Laboratory , 1996 .

[10]  Tayfun Akin,et al.  Fabrication of a three-axis capacitive MEMS accelerometer on a single substrate , 2015, 2015 IEEE SENSORS.

[12]  Alberto Corigliano,et al.  Dynamic nonlinear behavior of torsional resonators in MEMS , 2014 .

[13]  Zhihua Chen,et al.  A double differential torsional accelerometer with improved temperature robustness , 2016 .

[14]  Dong-il Dan Cho,et al.  Highly programmable temperature compensated readout circuit for capacitive microaccelerometer , 2010 .

[15]  Yuelin Wang,et al.  A novel capacitive accelerometer with a highly symmetrical double-sided beam-mass structure , 2012 .

[16]  F. Rudolf,et al.  Navigation grade MEMS accelerometer , 2010, IEEE/LEOS International Conference on Optical MEMS.

[17]  Chul Hyun,et al.  Resonant Loop Design and Performance Test for a Torsional MEMS Accelerometer with Differential Pickoff , 2007 .

[18]  Gerhard Lammel.  The future of MEMS sensors in our connected world , 2015, 2015 28th IEEE International Conference on Micro Electro Mechanical Systems (MEMS).

[19]  Christian Falconi,et al.  CMOS microsystems temperature control , 2008 .

[20]  Thomas G. Sugar,et al.  Characterization of Sandia Capacitive Comb-finger MEMS Accelerometers , 2015 .

[21]  Robert Puers,et al.  The characterization of a miniature silicon micromachined capacitive accelerometer , 1997 .