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

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.