Electroconductive hydrogels for bioelectronics: Challenges and opportunities

Electroconductive hydrogels (ECHs) have been extensively explored as promising flexible materials for bioelectronics because of their tunable conductivity and tissue-like biological and mechanical properties. ECHs can interact intimately with biosystems, transmit physiological signals, and are expected to revolutionize the convergence between organisms and electronics. However, there are still some challenges in utilizing ECHs as flexible materials for bioelectronics, such as mismatched stretchability with tissues, a lack of environmental adaptability, susceptibility to mechanical damage, inferior interface compatibility, and vulnerability to bacterial contamination. This review categorizes these challenges encountered in the bioelectronic applications of ECHs and elaborates on the strategies and theories for improving their performance. Furthermore, we present an overview of the recent advancements in ECHs for bioelectronic applications, specifically focusing on their contributions to healthcare monitoring, treatment of diseases, and human–machine interfaces. The scope of future research on ECHs in bioelectronics is also proposed. Overall, this review offers a comprehensive exposition of difficult issues and potential opportunities for ECHs in bioelectronics, offering valuable insights for the design and fabrication of ECH-based bioelectronic devices.