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

ABSTRACT

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.