Design and Analysis of ZnO Nanowires-Based Piezoelectric Accelerometer for Haptic Tactile Displays

Abstract

This thesis presents the proposed design and analysis of a Zinc Oxide (ZnO) nanowirebased accelerometer with a novel capability to measure acceleration in three directions. The piezoelectric properties of ZnO compose a self-powered acceleration sensing method by eliminating the power biasing requirement. The higher aspect ratio property of the ZnObased accelerometer enables larger deformation and higher piezoelectric response output. A mathematical model is derived to analyze the ZnO nanowire fundamental properties for its use in accelerometer applications. The model and design of the tri-axis accelerometer are further validated by using the finite element method (FEM) based numerical simulations. The key parameters of the accelerometer such as mechanical deformation, frequency response for displacement and voltage, and sensitivity are evaluated while applying the dynamic acceleration of 0.1 g and the static acceleration up to 50 g. The simulation results show a sensitivity of 0.25 V/g for an applied acceleration in the x and y axes (Shear acceleration) and 1.40 V/g sensitivity is achieved in the z-axis (Normal acceleration). The effect of different parameters, including varying nanowire aspect ratio, and nanowire array sizes are also evaluated to optimize the accelerometer's performance. The tri-axis acceleration sensing and self-powered capability of the proposed accelerometer make it a good choice for tactile haptic displays in biomedical applications.