Shape Memory Alloys and Elastocaloric Cooling

Elastocaloric cooling has high efficiency (~84% Carnot) and minimum environmental impact. In 2014, U.S. Department of Energy ranked it as the most promising new HVAC technology to replace vapor compression. While most shape memory alloys exhibit elastocaloric effect, only a few deliver an adiabatic temperature greater than 10 K. Currently, the only viable material for elastocaloric cooling application is the NiTi based shape memory alloy. While NiTi alloy has high latent heat (cooling power) and long fatigue life under compression, its prohibitively high cost makes it difficult for wide-spread industrial and consumer applications. In this talk, we will review the concept of elastocaloric cooling, the challenges and the state of the art development.