Sweat-adaptive adhesive hydrogel electronics enabled by dynamic hydrogen bond networks

Adhesive hydrogels offer an appealing way to the demand for flexible epidermal electronics. Despite the significant advances of adhesive hydrogel electronics, the unavoidable degradation of adhesion and associated diminished detection on sweaty skin are two long-standing bottlenecks for their practical applications. Herein, we present a sweat-adaptive adhesive poly(acrylamide)/cellulose (PAAm/Cel) hydrogel electronic via dynamic hydrogen bond networks. Increased sweat promotes the decoupling of hydrogen bonds within the hydrogel between PAAm and cellulose, leading to enhanced skin-hydrogel interfacial adhesion due to the strong binding of exposed abundant polar groups to the skin. The resulting PAAm/Cel hydrogel exhibits robust bioadhesion on sweating skin, with 268.3 J m−2 in interfacial toughness, 201.7 kPa in tensile strength, and 31.7 kPa in shear strength. Furthermore, the conformable and adhesive PAAm/Cel hydrogel electronics are demonstrated to produce high-quality and stable electromyogram (EMG) signals worked on persistent sweating skin. We believe that our designed adhesive hydrogel with dynamic hydrogen bond networks coupled with sweat is promising for tough bioadhesive electronics and enables bioadhesive technologies with high-level adaptivity in daily activities.