Source: Development of MEMS based pyroelectric thermal energy harvesters Proc. SPIE 8035, 80350V (2011); doi:10.1117/12.882125
Source: NewSceintist
Researchers at the Oak Ridge National Laboratory are developing a new type of high efficiency thermal waste heat energy converter that can be used to actively cool electronic devices, concentrated PV cells computers and large waste heat producing systems while generating electicity that an be used to provide electical power.
They have built an energy harvester that sandwiches a layer of pyroelectric polymer between two electrodes made from different metals. Just a few millimetres long, the device is deployed by wedging it between a hot surface and a cold surface
As the device warms, the polymer expands more than the electrode close to the cold surface, and the whole device bends like the bimetallic strip in a thermostat. It droops toward the cold surface, where it cools and then springs back toward the hot surface, warming up again. Soon the cantilever is thrumming between the hot and cold surfaces like the hammer of a wind-up alarm clock. Each time it is heated, the polymer generates a small amount of electricity which is stored in a capacitor