Prediction of Cross-Axis-Sensitivity of Inertial Micro-Sensor Through Modeling and Simulation
Prediction of Cross-axis-sensitivity of inertial micro-sensor through modeling and simulation
B. P. Joshi1, A. B. Joshi2, A. S. Chaware2 , S. A. Gangal*2
1
Armament Research & Development Establishment (ARDE), DRDO Ministry of Defence, Dr Homi Bhabha Road, Pashan Pune-411021, India Ph. No.+91-20-2588 4795, Fax No.+91-20-2589 3102 E-mail:bpjoshi@ieee.org 2 Department of Electronic Science, University of Pune, Pune-411 007, India Abstract: In addition to sensitivity and bandwidth, the cross-sensitivity is an important design parameter for acceleration/ inertial sensor design. In this paper prediction of cross-axis sensitivity of cantilever type of piezoresistive accelerometer is discussed. The effect of variation in geometrical parameters such as width and thickness of flexure & proof mass (PM) on crosssensitivity are studied. Optimization of cross-sensitivity by varying geometrical parameters has been attempted. This paper deals with simulations of skewed type (Flexure perpendicular to proof mass) and planar type (Flexure in plane with Proof mass) structure for cross-axis sensitivity analysis. The simulation and modeling has been carried using Coventorware MEMSCAD software. Keywords: Inertial sensor, Cross-sensitivity, MEMSCAD, FEM.
1 Introduction
Micromachined accelerometers are widely used in many applications. Large number of scientists all over the world are working on MEMS based acceleration sensors that are mostly either capacitive or of piezoresistive type. A piezoresistive type of acceleration sensor basically consists of a proof-mass attached to a micro-cantilever (Flexure) all made out of silicon. [1-4]. For piezoresistive accelerometer sensitivity S is defined as relative change in resistance per unit of acceleration. Following mathematical equation defines relation between sensor dimensions and its sensitivity [5]. Equation for sensitivity can be written as:
S
=
K .g .L t 2
(In Pa.)
…… Eq. 1
Where, S is the sensitivity [stress
B. P. Joshi1, A. B. Joshi2, A. S. Chaware2 , S. A. Gangal*2
1
Armament Research & Development Establishment (ARDE), DRDO Ministry of Defence, Dr Homi Bhabha Road, Pashan Pune-411021, India Ph. No.+91-20-2588 4795, Fax No.+91-20-2589 3102 E-mail:bpjoshi@ieee.org 2 Department of Electronic Science, University of Pune, Pune-411 007, India Abstract: In addition to sensitivity and bandwidth, the cross-sensitivity is an important design parameter for acceleration/ inertial sensor design. In this paper prediction of cross-axis sensitivity of cantilever type of piezoresistive accelerometer is discussed. The effect of variation in geometrical parameters such as width and thickness of flexure & proof mass (PM) on crosssensitivity are studied. Optimization of cross-sensitivity by varying geometrical parameters has been attempted. This paper deals with simulations of skewed type (Flexure perpendicular to proof mass) and planar type (Flexure in plane with Proof mass) structure for cross-axis sensitivity analysis. The simulation and modeling has been carried using Coventorware MEMSCAD software. Keywords: Inertial sensor, Cross-sensitivity, MEMSCAD, FEM.
1 Introduction
Micromachined accelerometers are widely used in many applications. Large number of scientists all over the world are working on MEMS based acceleration sensors that are mostly either capacitive or of piezoresistive type. A piezoresistive type of acceleration sensor basically consists of a proof-mass attached to a micro-cantilever (Flexure) all made out of silicon. [1-4]. For piezoresistive accelerometer sensitivity S is defined as relative change in resistance per unit of acceleration. Following mathematical equation defines relation between sensor dimensions and its sensitivity [5]. Equation for sensitivity can be written as:
S
=
K .g .L t 2
(In Pa.)
…… Eq. 1
Where, S is the sensitivity [stress
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