Design and fabrication of individualized capacitive microsensor for tilt measurement

This paper discusses details of a capacitance based tilt microsensor. The microsensor is a miniature version of a previously reported imperfect sensor [1]. A simple, cost effective and rapid process for microsensor fabrication is developed. The microsensor consists of two layers of Conductive PolyDiMethylSiloxane (CPDMS) membranes that are stacked together to form the structural element. Steel balls on the CPDMS membrane increase the mass of the system, thereby improving its sensitivity. The steel balls are randomly distributed, which makes each sensor individual and unique. Capacitive electrodes are etched on a double sided Printed Circuit Board (PCB). Two electrode configurations, single and dual, are designed to convert the movement of the membrane into a change in capacitance. Compared to the previously reported sensor [1], the newly designed microsensor offers better sensitivity at a reduced size.