A new pressure microsensor based on dual-gate graphene field-effect transistor with a vertically movable top-gate: Proposal, analysis, and optimization

The combination of modern electronic devices and nanoelectromechanical systems (NEMS) has given new impulses to the development of sensors and biosensors. A new pressure microsensor based on graphene field-effect transistor (GFET) endowed with dual-gate design is proposed herein. The movable topgate concept is used as sensing principle to detect the pressure-induced nanoscale displacement. A compact GFET drain-current model based on drift-diffusion carrier transport and field-effect principle is employed for the performance assessment of the proposed pressure microsensor. The investigation includes the top-gate and dual-gate configuration, transfer characteristic behavior, sensitivity analysis, operating regime, and the impact of gates' biases on the microsensor sensitivity. The performance analysis reveals that the dual-gate GFET design outperforms the top-gated GFET in terms of sensitivity. In addition, the high back-gate voltage and the low drain-source voltage have been found useful in improving the sensitivity of the DG GFET-based pressure sensor. Moreover, a metaheuristic optimization technique based on genetic algorithm (GA) has been adopted to find the optimal sensor parameters values that lead to the best sensitivity performance. The merits of the proposed dual-gate GFET-based pressure microsensor, namely small-size, high-sensitivity, graphene cost, and CMOS compatibility, make it a promising candidate for high-performance pressure sensing applications. (C) 2020 Elsevier GmbH. All rights reserved.