A flexible micro fuel cell fabricated using a hybrid fabrication technique

Micro fuel cells are currently being investigated as replacement for both primary and secondary batteries. While many technological challenges remain in micro he1 cell research, the key issue for all micro he1 cells is the volume of the system. While significant advances have been made in reducing the number and size of required components, the cell itself is difficult to miniaturize. Many researchers have attempted to apply different variants of micro fabrication techniques to the fabrication of micro fuel cells. We have elected to pursue an unusual inside-out architecture, where the membrane is used as a substrate, and thick and thn film depositions are used to create the active layers of the cell itself By using a combination of analytical and h t e element analysis techniques, we were able to derive practical values for critical parameters including: the hydraulic hameter; electrode length; gas diffusion layer conductivity and porosity; and operating temperature of the he1 cell with respect to the environment. These values were used to create a new he1 cell fabrication technique and architecture, which used a hybrid fabrication technique where the tool and die were fabricated using micro fabrication techniques, but the cell itself was fabricated using traditional manufacturing techniques. To successfdly fabricate these designs, a new stable supported membrane, and a particle based castable diffusion layer were required. These new materials had unusual mechanical properties, as well as their desired electrochemical properties. Testing the cell we found performance significantly lower than predicted. We traced the performance shortfall to a lower than required cathode GDL conductivity and porosity. Significant advances in GDL material design will be required to maximize the potential of the cell architecture.