Fabrication and evaluation of a passive SU8-based micro direct glucose fuel cell

A passive micro direct glucose fuel cell (μDGFC) using SU8-current collector structures of 8 × 14 mm with a grid that allows the delivery of the reagents to the membrane-electrode assembly (MEA) by diffusion and with dimensions of ~ 200 × ~ 180 μm were fabricated by a UV-lithography technique. The SU8-current collectors were coated with Au to provide electric conductivity; a passive μDGFC was set by sandwiching an MEA between two SU8-current collectors and placed between two methacrylate pieces. The electrocatalysts consisted of commercial Au/C as anode and Pt/C as cathode. μDGFC characterization was done by measuring the polarization curves at a glucose concentration close to that found in human blood. The maximum power density achieved was ~ 0.30 mW cm⁻² using 5 mM glucose as fuel and oxygen delivered from air as an oxidant. The passive micro fuel cell showed a constant current density for 30 min at a potential of 0.3 V corresponding to the maximum power density.