Fabrication of conducting polymer microelectrodes and microstructures for bioelectronics

Abstract

Conducting polymers (CPs) are emerging as one of the most promising functional materials for bioelectronics and biointerfaces due to their high biocompatibility, intrinsic electrical and ionic conductivity, tunable mechanical properties and the capability of being functionalised through chemical modification. For bioelectronics applications, there is an increasing demand for miniaturisation of the devices, which will not only enable the exploring of, for example, the stimuli-response of single cells and the electrophysiological mapping at a cellular resolution, but also benefit the advanced clinical diagnostics and therapeutic applications, especially when implantable and other wearable medical devices are needed. One critical step for miniaturising CP-based bioelectronic devices is the microfabrication of CPs. Driven by this demand, a variety of microfabrication techniques have been developed or adapted to CPs. As a result, a wide range of CP microelectrodes in both 2D and 3D formats have been successfully fabricated and successfully employed in a variety of bioelectronic applications, ranging from the acquisition of biological information (sensing and recording), controlling the physiological behaviour (stimulation) of cells and tissues to biomimetic applications such as artificial muscles. These CP-integrated microbioelectronic devices bring about unprecedented possibilities and exciting prospects for fundamental research and clinical applications of organic bioelectronics. This review addresses the recent advancements in the fabrication techniques of 2D and 3D CP microelectrodes and the applications of such electrodes in bioelectronic devices. We aim at providing insights into these emerging techniques that may inspire the development of the next generation of bioelectronics.