Electrocaloric Cooling

The electrocaloric effect describes a reversible temperature change in dielectric materials submitted to an applied electric field. Adiabatic polarization raises their temperature, and adiabatic depolarization lowers it, analogous to temperature changes that occur when a gas is compressed or expanded. For refrigerator application, the reverse Brayton cycle is currently the most promising for practical implementation. The electrocaloric effect provides a large material efficiency. However, existing refrigerator prototypes lack from the absence of efficient heat switches for thermal linkage to the load and the heat sink. Cooling power densities of a few W/cm2 and temperature spans in the order of 20 K (in regeneration systems) are achievable at a cycle time of 100 ms.