Optimized Analysis of Sensitivity and Non-Linearity for PDMS-Graphene MEMS Force Sensor.

The aim of this paper is to analyze and evaluate the sensitivity and non-linearity of graphene piezoresistive MEMS force sensor by optimizing its geometrical parameters. In this work, important factors affecting sensitivity and non-linearity were identified such as geometrical dimensions of microcantilever, modulus of elasticity of material, shape, placement, doping concentration, and dimensions of piezoresistors. Based on the selection of factors, Taguchi optimization method was employed for finding an optimal combination of microcantilever and piezoresistor dimensions. The optimized model of force sensor was designed with the aid of obtained dimensions of microcantilever and piezoresistors. For designing and simulation, COMSOL Multiphysics® 5.3a software is used. The major findings revealed that the designed sensor possess a high sensitivity of 3.93 mV/µN in an operating range from 0 to 106 µN with 0.0092% of non-linearity. An important feature of flexibility is introduced in the sensor by incorporating the novel combination of Polydimethylsiloxane (PDMS) as a flexible substrate and graphene as a flexible piezoresistor. The originality also lies in the area of the cumulative analysis of various input factors which are listed above altogether in one platform. [ABSTRACT FROM AUTHOR]