Biomimetic and Gel-Mediated Tissue Adhesive Structures for Skin Conformal and Multifunctional Bioelectronics.

Epidermal electrodes are essential for wearable bioelectronics in health monitoring and rehabilitation. However, current options are limited: adhesives irritate skin, hydrogels dry out, ultrathin films cannot deliver high currents, and sharp microstructures concentrate current, risking burns. Achieving repeatable gel-mediated adhesion with uniform current distribution on curved, moving skin remains a major challenge. In this study, we present biomimetic electrodes using carbon nanotube-silicone elastomer (CNT-elastomer) composites patterned with octopus-inspired suction units and polyethylenimine (PEIE)-induced microwrinkles. With an interfacing electrolyte gel, these electrodes achieve strong, repeatable skin adhesion of up to 77 ± 5 J m-2 in the normal direction and maintain performance over 100 reapplication cycles. Charge-transfer resistance across the skin is reduced by 20-fold, establishing low-impedance interfaces. The electrodes record electrophysiological signals with clinical-grade fidelity and deliver surface functional electrical stimulation with 50% higher efficiency in large muscle groups. Manufactured through facile fabrication methods of mold casting and leaving no skin residue, the electrodes exhibit skin-matching mechanical compliance and efficient charge transfer, advancing comfortable and durable bioelectronic interfaces for rehabilitation, assistive neurotechnology, and next-generation healthcare devices.