Chapter 2 - MEMS-Based Micro Fuel Cells as Promising Power Sources for Portable Electronics

Abstract

This chapter focuses on miniature fuel cells fabricated using microtechnologies techniques. Among the numerous solutions developed today, the basic structure of fuel cells remains the same: thin film planar stack (generally silicon, foils, polymer, or glass) with commercial ionomer, most often Nafion®, the reported layers being micromachined (microchannels or porous media) for gas/ liquid management and coated with gold for current collecting. One of the technological ways to miniaturize fuel cells is to make use of standard microfabrication techniques mainly used in microelectronics and, more especially, the fabrication of micro- and nano-electromechanical systems (MEMS/NEMS). More and more papers show a growing interest in developing MEMS-based fuel cells, either directly with silicon substrates, or adapting the methods to other substrates such as metals or polymers. These techniques enable notably mass fabrication at low cost (very large number of devices on a very small area), which could lead to a reduction in the global cost of miniature fuel cells. As the basic material for MEMS technologies, silicon remains the most employed material for MEMS-based fuel cells, but foils and polymers have shown interesting potential for future commercial development. Thus, in most of the cases, this is often the simple application of microtechnology to conventional fuel cell structures.