Application of conducting polymer technology in microsystems

Abstract Conducting polymers are a new type of organic material that offer enormous potential for application within the field of microsystems. In this paper we review the basic properties of conducting polymers and discuss their application in electronic, mechanical and (bio)chemical microsystems. For instance, we have found that thin films of poly(pyrrole)/decanesulfonate have both a low friction coefficient (ca. 0.1) and wear rate (ca. 1 nm cm −1 ) that are similar to values observed for PTFE, yet possess relatively high electrical and thermal conductivities. In addition, conducting polymers can be readily electrodeposited onto planar or curved micromechanical structures, such as microslideways, micromotors or microturbines, to provide a bearing material of superior performance to standard micro-engineered materials (e.g. Si, SiO 2 , Si 3 N 4 ) and better processability than PTFE. In addition, conducting polymers can be used as gas-sensitive films in microelectronic devices. They have been shown to have a rapid, reversible ppm sensitivity to polar organic compounds (e.g. alcohols, ketones, aldehydes and fatty acids) without interference from common gases such as CO 2 , CO, CH 4 and N 2 . Conducting polymers are currently being used in commercial electronic noses, and integrated microsystems are being realised with the advent of custom microsensor array devices and application-specific integrated circuit chips.