Flexible enzymatic biofuel cell based on 1, 4-naphthoquinone/MWCNT-Modified bio-anode and polyvinyl alcohol hydrogel electrolyte

To meet the emerging power demand of microelectronic and electronic skin based sensing platform, enzymatic fuel cells have received increasing attention due to their good human's compatibility, easy integration and cost effectiveness. Herein, we use multi-walled carbon nanotube/naphthoquinone to modify the lactate oxidase bio-anode to facilitate the electron transfer between electrocatalytic active site and electrode support. Polyvinyl alcohol hydrogel serves as the separator and lactate container. The bio-anode, Pt/C cathode and hydrogel are assembled in layer-by-layer structure, which can successfully utilize pre-stored and external lactate from human's sweat to generate the electricity. It delivers a power-density of 62.2 ± 2.4 μW cm-2 under bending/torsion conditions. Given that the broad substrate scope in sweat and easily assembled structure, it provides a plausible solution to power the miniaturized sensors and generic circuits.