Experimental study on mechanical power generation from MEMS internal combustion engine

A micro-electro-mechanical-system internal combustion engine (MEMS IC engine) is fabricated to demonstrate the energy conversion from heat to mechanical power. The dimensions and surface-to-volume ratio of combustion chamber are 5 mm × 3 mm × 1 mm (0.015 cc) and 3.07 mm−1, respectively. The reciprocation motion of a piston can be sustained by the force balance between combustion pressure and the repulsion force of an elastic spring. A premixture gas composed of hydrogen and oxygen is used for fuel under stoichiometric combustion (equivalent ratio is 1). The combustion is confirmed by pressure measurement and the direct observation of flame propagation. A high-speed CMOS camera is adopted for the flame observation. A maximum combustion pressure of 142.6 kPa, a displacement of 9.5 mm3, and a mechanical power of 29.1 mW were obtained for the MEMS IC engine. This experimental evidence provides a positive outlook for the materialization of the MEMS heat engine concept.