Electrostimulus Phase‐Transition Mediated Robust Adhesive Hydrogels

ABSTRACT Adhesive hydrogels are crucial for interfacing wearable electronics with substrates, yet the inherent trade‐off between interfacial adhesion and cohesive strength always limits their application performance. Here, we present an adhesive hydrogel based on lignin‐mediated catechol chemistry and salt hydrate phase‐transition, which achieves synergistic enhancement of interfacial adhesion and cohesive strength upon 1 V electrostimulated crystallization. The hydrogel is soft and exhibits mild adhesion to various substrates in amorphous state. Electrostimulus‐induced phase‐transition realizes a significant increment of cohesive strength and boosts interfacial adhesion by up to 8–40 times (exceeding 3000 J m −2 ) on skin. The adhesion‐enhancement mechanisms on different substrates are elucidated via multi‐scale experimental designs and molecular simulations. When the hydrogel is applied as the adhesive layer, the assembled elastomer sensing devices inherit the electrostimulus adhesion‐enhancement and shape‐memory properties, significantly improving signal transmission stability and motion‐interference resistance. This study offers a simple and versatile strategy for stimuli‐enhanced adhesives, deepens the understanding of phase‐transition regulated adhesion behaviors, and supports the development of large‐area flexible devices for intelligent robotics and human‐computer interactions.