SOLID-STATE REFRIGERATION

Conventional refrigerators and air conditioners use vapor compression cycles to achieve cooling. The high global warming potential of conventional refrigerants and moderate thermodynamic efficiencies of existing devices, however, motivate exploration of alternative cooling technologies.

The Peltier effect forms the basis of well-known thermoelectric coolers. Despite intense research efforts over the past two decades, consuming tens of millions of dollars of research funding, no viable thermoelectric materials with adequate thermodynamic efficiencies have been discovered.

Our research group investigates an alternative heat pumping technology based on the electrocaloric effect. By applying or removing electric fields to polarizable materials, one can control the component of entropy that is associated with polarization and thereby induce cooling (or heating).

Our group demonstrated the world's very first working prototype of a solid-state electrocaloric cooler (Applied Physics Letters, Vol. 100, 242901 (2012); doi: 10.1063/1.4729038).

In collaboration with Professor Pei's group at UCLA Materials Science and Engineering Department, we also recently demonstrated flexible electrocaloric coolers (Science Vol. 357, 1130–1134 (2017) ).