Power Generation At The Micro Scale

The present work is to show the development of micropower systems or power MEMS characterized by thermal, electrical and mechanical power density 1~20 Watts in sub-centimeter-sized packages. Three kinds of typical micro power systems, namely, the micro-gas turbine engine, the MEMS rotary micro engine, and a micro thermoelectric system, are described in this paper. A novel microthermophotovoltaic (micro-TPV) system, which is being developed in NUS, is also introduced in this work. The system uses hydrogen as fuel and is able to deliver electrical power in the order of watts in a package less than 1 cubic centimeter in volume. The main components of the system are a heat source, a selective emitter, and a photovoltaic (PV) array. The performance of the system is largely affected by the materials of the emitter and the PV cells. When the emitter is made of Co/Ni-doped MgO, and the PV cells are made of GaSb, a 4.4 W electrical power output can be expected.