Conducting Polymer Hydrogels for Hydrogel Bioelectronics

Electrical interfacing with biological tissues for interrogation and modulation of living systems – or bioelectronics – is one of the most important modes of communication between artificial machines and biological organisms. In conventional applications, bioelectronic interfacing has relied on conventional electrodes and devices made of metals and engineering solids like plastics and elastomers. However, the stark dissimilarity between biological tissues and conventional device materials has posed great challenges for long-term bioelectronic interfacing with living systems, especially for implantable devices. To address these challenges, electrically conductive hydrogels – polymer networks infiltrated with large amounts of water with electrical conductivity – have been substantially studied in the last decades owing to their unique advantages including tissue-like mechanical properties and high water contents, favorable electrical properties, and in vivo biocompatibility. However, conducting polymer hydrogels has faced several key challenges in their practical uses including poor electrical and mechanical properties in physiological environments, unreliable integration within devices and to the target biological tissue, and difficulties in small-scale fabrications into functional devices. In this talk, several advances in conducting polymer hydrogels to address these challenges will be discussed toward the vision of hydrogel bioelectronics.