In recent years, the development of fuel cells has proceeded rapidly, and so the reforming of methanol to produce hydrogen has become a serious problem. Supplying hydrogen from a micro methanol reformer to fuel cells is an important topic. The structure of a micro flow channel must support the transfer of external heat to the reform reaction, facilitating the diffusion of methanol vapor into the catalyst layer, increasing the rate of transfer of hydrogen. In this investigation, the micro-electro-mechanical systems (MEMS) technique is utilized to fabricate micro pressure, temperature and flow sensors. Polyimide film (PI) exhibits high temperature resistance and stress corrosion resistance, and is adopted herein as a flexible substrate. In future work, such micro sensors will be embedded in a micro methanol reformer for in-situ diagnosis.
Thermal and Coriolis type micro flow sensors based on surface channel technology