Towards fully polymeric MEMS: Fabrication and testing of PEDOT/PSS strain gauges

In recent years first commercial devices based on organic electronic materials entered the market. Recent market studies mention the necessity to include sensors in the design of organic electronic devices in order to broaden the range of applications. It is therefore essential to identify potential organic sensor materials and to develop processes and methods to structure and characterize them. Widely used in organic electronics is the complex of the intrinsically conductive polymer poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate acid (PEDOT/PSS). In this paper we first present a lift-off process for patterning thin PEDOT/PSS films. Crucial deposition parameters are systematically investigated and subsequently a reliable micropatterning process defined. Then a design for fully polymeric pressure sensors made from polyimide (PI) membranes and PEDOT/PSS strain sensors is proposed. Preliminary test results as proof-of-concept are finally shown.