US-based Neah Power Systems is taking an innovative approach to fuel cell development that is expected to address the traditional challenges associated with micro fuel cells.
It all begins with porous silicon, used as the core of the fuel cell engine. This architecture eliminates the need for the polymer membrane used in traditional PEM-based fuel cells. The porus silicon structure, approximately 400 microns deep, is much thicker than the 10-micron depth of a membrane in a traditional PEM-based cell. This design is expected to enable a much larger reaction surface area, enabling high power in a small form-factor.
Liquid electrolyte flows throughout the porous silicon substrate . This, the company says, allows for higher levels of exposure of reactants, electrolyte, and catalyst the interaction required for electricity generation.
Taken together, the patented silicon-based architecture is designed to result in higher levels of efficiency and electro-chemical activity, which translate into much higher power densities when compared with traditional PEM-based designs.
Higher power densities enable lighter-weight, smaller form-factors and drive down costs. The practical result is that Neah Power’s fuel cell is expected to fit within a notebook PC’s internal battery cavity instead of outside the computer.
Importantly, the Neah Power fuel cell captures water vapour by-products in the fuel cartridge. Other fuel cell designs vent water vapour, which can be messy and have adverse effects on sophisticated electronic gear.
Presently, the company is developing a prototype to power a notebook computer. This is expected to provide all-day computing for an ultra-light notebook PC, which typically requires about 120 Watt-hours (Whrs) of energy for 8 hours of operation.