Open Competition 3 - Electronics and Photonics
Porous Silicon Electrode All Liquid Fuel Cells
Develop a miniature direct methanol fuel cell using novel porous silicon electrodes and microfluidics for handling fuel and oxidant, potentially replacing environmentally challenging rechargable batteries while offering longer run times, higher power output, and instantaneous recharging for portable electronic devices.
Sponsor: Neah Power Systems, Inc.22118 20th Avenue, SE
Bothell, WA 98021
Leveraging standard semiconductor manufacturing capabilities, Neah Power Systems, Inc., intends to demonstrate a novel, cost-effective approach for mass-producing small, energy-dense fuel cells to power portable electronic devices, a $4.5 billion market dominated by lithium-ion and nickel-metal-hydride rechargeable batteries. Key elements of Neah's direct methanol fuel cell (DMFC) technology are the use of porous silicon substrates strategically doped with uniformly distributed catalyst particles. The company will use MEMS (micro-electro-mechanical systems) technology to direct and control the flow of streams of fuel, oxidant, and electrolyte as they circulate among the catalyst-coated porous-silicon electrodes. The porous structure results in a large contact surface area that should greatly increase efficiency as compared to other DMFC designs. DMFCs, in which methanol reacts with oxygen to produce electrical power, have been eyed as portable power sources. However, current designs are too large to substitute for rechargeable batteries, and they are expensive to manufacture. Neah's three-dimensional electrodes translate into more current-producing electrochemical reactions per unit of surface area. The result is a significant increase in power density. Neah estimates that its approach has the potential to produce fuel cells that are 40 percent lighter and store two to three times more energy than a similar-sized lithium-ion battery. The Neah design will be implemented in silicon and plastic with manufacturing processes and equipment currently in use by the semiconductor industry, enabling mass production at low cost. To accomplish its objective during this two-year project, however, Neah must demonstrate that it can attain the power-density levels necessary to compete with batteries. It also must demonstrate methods to make large silicon wafers with the desired pore structure, underlain by flow channels for circulating reactants. Although Neah has attracted some venture capital funding, it has not been enough to overcome all the challenges to completing a prototype fuel cell. ATP funding will enable the early-stage company to accelerate its research efforts and address important manufacturing issues. The porous silicon technology to be developed by Neah also has potential application in fluid filters, electric optical products, sensors, capacitors, MEMS devices, and other components.