Giant mechanocaloric materials for solid-state cooling

This article reviews the research progress of measurement techniques and materials on the mechanocaloric effect over the past few decades. Mechanocaloric materials can be divided into elastocaloric and barocaloric materials depending on the applied uniaxial stress or hydrostatic pressure. Elastocaloric materials include non-magnetic shape memory alloys, polymers, and rare-earth compounds. Barocaloric materials include magnetic shape memory alloys, ferroelectric ceramics, superionic conductors, and oxyfluorides. The mechanocaloric effects of these classes of materials are systematically compared in terms of the isothermal entropy change and adiabatic temperature change. In addition to the thermal effects, other characteristics closely related to the application of mechanocaloric materials are also summarized. Finally, perspectives for further development of mechanocaloric materials in the solid-state cooling area are discussed.