Porous Platinum Electrodes Fabricated by Cyclic Electrodeposition of PtCu Alloy: Application to Implantable Glucose Fuel Cells

We demonstrate the application of cyclic electrodeposition of PtCu alloy to fabricate porous platinum electrodes for implantable glucose fuel cells. Depending on the number of deposition cycles, electrodes with controllable specific surface area can be fabricated, their roughness factors ranging from 20 (slightly roughened) to 3100 (highly porous). Adjusting the specific surface area of the electrode from low to high determines whether it functions as cathode or anode, respectively. Compared to state of the art, this process is beneficial due to shorter fabrication times, lower temperatures, and the requirement of only one process for the fabrication of both electrodes. Correspondingly fabricated glucose fuel cells showed a power density of 5.1 μW cm –2 under close to physiological conditions, which is an improvement by 16% compared to earlier designs. During continuous operation over 90 days the fuel cell showed a mean continuous decay of about 0.8% per day, which is related to catalyst poisoning at the anode. Future work will thus have to focus on the improvement of long-term stability instead of power density.