Development and applications of mussel-inspired composite hydrogels for flexible bioelectronics

In recent years, conductive hydrogels have been developed and applied in electronic skin, soft actuator and bioelectronics due to their unique electrical conductivity, self-healing and mechanical properties. These remarkable characteristics make the hydrogel-based conductive strain sensor show excellent performance in identifying external stimuli and human health monitoring. And these composite hydrogels generally rely on external auxiliary for adhesion to human tissues, but it not easy to peel off and lead to unstable performance in practical applications. Therefore, the realization of full and repeatable adhesion to biological tissue has become an urgent problem to be solved. Recently, mussel-inspired composite hydrogels have become an ideal material for designing self-adhesive bioelectronic products. Due to its unique advantages and can integrate a variety of functional properties into integrated bioelectronic devices, which is of great significance for the application of conductive hydrogel in medical and health care. In this review, we focus on the adhesion mechanism of mussel, the application of catechol and its analogues in conductive hydrogels, and the design and application of mussel-inspired self-adhesive flexible electronics.