Place a rubber band between your fingers and stretch it quickly and rapidly (while trying not to snap it). If you do this quickly enough, you should notice that the rubber band becomes warmer than it was when it was lying loose in your hand. And once you release the tension on the band, it will cool back down.
The rubber band is an example of the elastocaloric effect, a phenomenon that scientists think provides an opportunity to develop greener and more energy-friendly fridges, heat pumps, and air conditioners. Since these devices can account for 25-30% of power consumed in business and homes, this could deliver significant benefits not only for energy bills, but for the