A Bimetallic Micro Heat Engine for Pyroelectric Energy Conversion

We present a novel concept of electric power generation from a spatial temperature gradient, achieved by integrating pyroelectric generators (PEGs) into a self-oscillating micro heat engine. The micro heat engine moves the PEGs between a hot and cold reservoir, thus bringing them in an alternating contact with a higher and lower temperature. By their pyroelectric nature, the PEGs convert this periodic temperature variation into electrical energy. The micro heat engine is fabricated from a 280 μm thick bimetallic strip and the PEGs from a 250 μm thick PZT sheet. At an oscillation frequency of 0.19 Hz the device generates 4.4 μW of electrical power from a 96 K temperature difference.