Adhesive Nonfibrotic Bioelectronic Interfaces on Diverse Peripheral Nerves for Long-Term Functional Neuromodulation

This study introduces an ultrathin, adhesive, hydrogel-based nerve interface (A-HNI) engineered to conform to diverse peripheral nerves without eliciting fibrotic encapsulation. The A-HNI integrates a conductive polymer–hydrogel composite, an adhesive zwitterionic surface layer, and a mechanically compliant architecture that matches nerve deformation during locomotion. Across multiple rodent nerve targets—including sciatic, tibial, and vagus—the device maintained intimate contact for more than 120 days while avoiding the capsule formation typically induced by implanted electrodes. Electrophysiological studies demonstrated stable stimulation thresholds, reduced impedance drift, and improved signal-to-noise ratio. Long-term histology confirmed minimal macrophage infiltration and negligible collagen deposition at the interface. Mechanical characterization revealed that the composite hydrogel exhibits near-nerve-matched modulus and high stretchability, supporting its ability to accommodate physiological strain without delamination or mechanical failure. Together, these findings demonstrate a fibrosis-free neuromodulation platform with broad applicability to chronic peripheral nerve interfaces.