MICROTHERMOPHOTOVOLTAICS POWER SYSTEM FOR PORTABLE MEMS DEVICES

A novel concept of microthermophotovoltaics (MTPV) systems is proposed for powering MEMS devices. The system uses hydrogen or hydrocarbon as fuel and does not involve any moving parts. Its fabrication and assembly are relatively simple. In this article, energy conversion efficiencies of a GaSb MTPV system incorporating broadband SiC and selective emitter material were first analyzed. Numerical and experimental studies on microcom-bustion processes in the MTPV system were carried out. The results show that uniform temperature distribution above 1000 K along the wall of microcylindrical combustors with a unique backward-facing step can be achieved. Finally, a prototype MTPV power system using SiC as the material for combustor and emitter, and a hexagonal GaSb cell array for energy conversion, was fabricated and tested. Electric power output ranging from 0.07 W to 0.74 W was measured. The potentials and further approaches of MTPV system were discussed. It is believed that MTPV would be a very attractive and competitive system among other power MEMS developments. With miniaturization of electronic devices such as notebook computers and cell phones, and increasing demands on microelectromechanical system (MEMS), needs fo