Surface Micromachined Polymer Capacitive Accelerometer Array Utilizing Fringe Electrical Field

This paper reports a unique capacitive accelerometer array design, by using the fringe electrical field between planar electrical conductors and a polymer/air dielectric. Micromachinable SU-8 polymer technology is used. The proposed polymer sensor utilizes the fringe electrical field, which requires no metallization process on the polymer, hence greatly simplifying the fabrication process to create a polymer capacitive inertial device. The polymer used, SU-8, a negative photoresist, can precisely be defined by UV illumination. The proposed process requires no high temperature steps (< 200 °C), nor harsh chemical solutions, which renders the technology compatible with CMOS technology. Both electrostatic and dynamic characterizations have been conducted.