Moisture‑Triggered Electricity Generation via Radiative Cooling Fiber‑Based Dressings for Accelerated Wound Healing.

Moisture-driven power generation from wound exudate provides a promising route toward in situ self-powered wound therapy. However, its performance is limited by environmental factors, especially elevated external temperatures, which impairs water retention and disrupts humidity gradients, consequently degrading power output. Here we demonstrate a heterogeneous short-fiber humidity-powered band-aid integrated with radiative cooling technology (CE band-aid). Results show that the degradable gelatin/Poly(L-lactic acid) (PLLA)/MXene scaffold generates an open-circuit voltage of ∼120 mV and a current of ∼12 µA under wet conditions. A surface layer of polyethylene-particle-modified fibers (PLLA/PE) endows the device with high solar reflectivity (∼98%) and mid-infrared emissivity (∼93%). Under outdoor sunlight, the PLLA/PE layer maintains a surface temperature ∼10°C below ambient levels and retains 10% more moisture than commercial gauze. In rat and pig full-thickness skin defect models, PLLA/PE reduces skin temperature by up to 6.5°C, and this cooling effect significantly suppresses inflammation. Compared with other groups, the CE Band-aid upregulates the Pi3K-Akt signaling pathway via continuous electrical stimulation, promotes tissue regeneration, and inhibits apoptosis-related signaling pathways, thereby significantly shortening wound healing time. This work presents a novel, zero-energy strategy for accelerated wound regeneration.