Dopamine-Triggered Hydrogels with High Transparency, Self-Adhesion, and Thermoresponse as Skinlike Sensors.

Mussel-inspired conductive hydrogels are attractive for the development of next-generation self-adhesive, flexible skinlike sensors. However, despite extensive progress, there are still some daunting challenges that hinder their applications, such as inferior optical transparency, low catechol content (e.g., poor adhesion), as well as limited sensation performances. Here, we report a dopamine-triggered gelation (DTG) strategy for fabricating mussel-inspired, transparent, and conductive hydrogels. The DTG design leverages on the dual functions of dopamine, which serves as both polymerization initiator and dynamic mediator to elaborate and orchestrate the cross-linking networks of hydrogels, allowing for pronounced adhesion, robust elasticity, self-healing ability, excellent injectability and three-dimensional printability, reversible and tunable transparent-opaque transition, and thermoresponsive feature. These preferable performances enable DTG hydrogels as self-adhesive, flexible skinlike sensors for achieving multiple sensations toward pressure, strain, and temperature, even an extraordinary visual perception effect, making it a step closer in the exploration of future biomimetic skin.