Flexible Amorphous Silicon Radial Junction Patches Promote Skin Regeneration by Offering Wireless Photoelectric Neuromodulation

Photoelectric stimulation offers a promising method for creating noninvasive and durable interfaces with biological tissues, particularly in treating nerve injuries. However, developing flexible and high-performance photoelectric stimulators remains a challenge. In this study, we present an accessible and cost-effective strategy for fabricating an ultraflexible and biocompatible photoelectric patch designed for wireless, light-induced electrical stimulation to promote nerve repair in skin wounds. Using low-temperature chemical vapor deposition, we created flexible photoelectric films based on three-dimensional (3D) amorphous silicon radial p-i-n junction (RJ) nanowires, which exhibit a high open-circuit voltage of 0.79 V and a short-circuit current of 10.5 mA/cm² under standard AM 1.5 G illumination conditions. The device exhibits good electrochemical performance in solution, featuring high interfacial capacitance and efficient photocurrent generation (∼0.64 mA/cm²), which ensures a stable, capacitive charge injection crucial for effective bioelectrical stimulation. Importantly, the free-standing RJ films can be reliably transferred onto soft poly(dimethylsiloxane) substrates to produce flexible photoelectric patches that maintain intimate contact with curved tissue surfaces. The RJ patches show high biocompatibility and effectively enhance neurite outgrowth and wound healing under safe visible light, promoting both vascular regeneration and neural restoration. This flexible patch holds potential in wireless electrical stimulation, providing a robust and noninvasive solution for comprehensive wound repair and functional tissue regeneration.