Flexible Carbon Film‐Based Wearable Epidermal Hybrid Biofuel Cell for Bioenergy Harvesting and Biomarker Monitoring

ABSTRACT Developing flexible, self‐sufficient power generators is of significance for burgeoning wearable electronics. Biofuel cells (BFC) that harness perspiration metabolites can potentially offer a promising route toward simultaneous energy generation and self‐powered sensing. However, insufficient power supply and susceptible enzyme‐induced instability hinder widespread adoption. Herein, an enzyme‐free hybrid glucose BFC is designed employing nitrogen‐phosphorus doped carbon (NPC) flexible film derived from self‐assembly graphene/polymer hydrogels, incorporating platinum nanoparticles for glucose oxidation and manganese dioxide‐based O 2 ‐independent capacitive cathode. The O 2 ‐independent design eliminates potential interference to the anodic reaction, enabling a markedly enhanced maximum power density of 680 µW cm −2 and an open circuit voltage of 0.92 V, alongside operational stability exceeding 30 days. When functioning as the self‐powered glucose sensor, it offers a wide range of 0.05–20 mM. Integrated into a conformal wearable system, the device enables bioenergy harvesting from human sweat and real‐time glucose monitoring via compact signal processing electronics. This work underscores the potential of flexible hybrid BFC systems and paves the way for powering next‐generation wearable bioelectronics in personalized healthcare.