Miniature fuel cell with conductive silicon electrodes

We report on a direct methanol fuel cell (DMFC) with conductive silicon electrodes. In our design, the electrodes are made of silicon instead of carbon. We fabricated a porous structure at the bottom of the channels using the DRIE process. Pt catalyst was electrodeposited onto the surface of the electrodes. A Nafion 115 membrane was sandwiched between two 280-μm-thick electrodes with a microporous structure 30 μm thick. Open circuit voltage of 150 mV was observed with 1 M methanol feed. Maximum power density of 0.016 mW/cm was achieved. Since the electrode and the channels are fabricated in a single wafer, it is possible to decrease the total thickness of the fuel cell by a using thinner wafer.