The electrocaloric effect is defined as the reversible adiabatic temperature change or isothermal entropy change of a dielectric material under application or withdrawal of an electric field. It is a promising approach for the development of alternative cooling technologies.
Ferroelectric materials exhibit a high electrocaloric effect in the vicinity of the ferroelectric-to-paraelectric phase at Curie temperature. By application of an electric field ferroelectric domains will align and the material will heat up. This happens very rapidly. The thermal energy can be dissipated to a heat sink and the material will cool to its initial temperature. By removal of the electric field ferroelectric domains will misalign while the component will cool down and can absorb thermal energy from a heat source. By integrating electrocaloric materials into an electrocaloric cycle, efficient cooling systems or heat pumps can be built without need for complex mechanics. This makes them very attractive for solid state cooling.
The integration of electrocaloric materials into practical cooling devices involves several challenges, including optimizing the material composition, improving thermal management, and ensuring long-time stability.
Multilayer ceramic components analog to commercial multilayer ceramic capacitors (MLCCs) are particularly suitable since they exhibit higher refrigerant volume compared to thin films as well as increased dielectric strength compared to bulk materials.
Fraunhofer Institute for Ceramic Technologies and Systems IKTS
