A Wearable Electrochemical Patch for Sustained Local Oxygen Therapy of Chronic Wounds

ABSTRACT Wearable bioelectronics are dominated by low‐power sensing, whereas effective therapy requires sustained molecular fluxes that conventional soft devices rarely support. A central challenge is simultaneously maintaining solid–solid charge transport, hydration‐dependent ionic conduction, and biofluid resistance within a lightweight, fixture‐free architecture. Here, we report a vapor‐fed electrochemical materials architecture for skin‐conformal oxygen delivery. The system integrates a mechanically interlocking 3D current collector/catalyst interface to stabilize electronic transport, femtosecond‐laser‐defined microchannels to reconstruct vapor‐phase mass transport within an all‐solid‐state membrane electrode assembly, and a phase‐selective porous barrier blocking exudate intrusion while preserving gas diffusion. This hierarchical design enables an ultralight (<4 g) patch to operate at high current densities (>100 mA cm −2 ), sustaining continuous operation for 735 h to deliver 16.8 L of high‐purity (>99%) O 2 . The architecture remains stable for >500 h in simulated exudates and supports efficient transdermal oxygen transport across porcine skin. In a rat pressure–ulcer model, short‐course treatment accelerates early wound closure 1.7‐fold at day 3, enhancing M2 macrophage polarization and vascular normalization. These results establish a materials framework for translating wearable bioelectronics from passive information interfaces to active molecular‐delivery systems.