Wafer-scale microfabrication of flexible organic electrochemical transistors

Abstract

We describe a photolithographic process to fabricate organic microdevices on flexible substrates that relies on photolithography and dry etching and is entirely compatible with standard cleanroom wafer processing equipment. A conductive polymer is used as active material to fabricate organic electrochemical transistors on a flexible polyimide substrate. The transistors are operated both with a solid-state ion gel electrolyte and an aqueous electrolyte, thus demonstrating their applicability as building blocks as both flexible integrated circuits and biosensors. Miniaturized transistors with 2 μm-long channels are also demonstrated to showcase the ability of the microfabrication process to define small features. We believe the proposed process flow offers a high resolution alternative to printing techniques by taking full advantage of the superior reliability of established semiconductor device manufacturing techniques and facilities.