Numerical analysis of touch mode capacitive pressure sensor using graphical user interface

Abstract

Design through numerical methods requires experimental verification of micro electrical mechanical system (MEMS) processes and numerous parametric analyses. In particular, to evaluate the performance of capacitive pressure sensor, electrical calculations are necessary along with structured numerical analysis. For this reason, pre- and post- processors are necessary that would create models and manage results through a dedicated graphic user interface for sensor analysis. Therefore, this study is designed to make efficient and convenient numerical methodology of touch mode capacitive pressure sensor (TMCPS) using graphical user interface (GUI), appropriate for measuring tire pressure, and analyze its capability and linearity responding to geometric design parameters. Design parameters are size of diaphragm, thickness of diaphragm and gap distance between diaphragm and insulator. All of the analysis process is controlled by GUI program. Analysis results show capacitive-pressure graph, regression curve and pressurecontact area graph using calculation and finite element analysis. This research shows negative association between the thickness and the gap for optimum diaphragm. Optimum diaphragm is 2.5mm by 2.5mm size, 25μm thickness, 4.5 μm gap within 20~40psi which means the range of tire pressure. © 2013 Springer-Verlag GmbH.