Memory alloys that avoid exhaustion: Shape memory alloys can pop back into shape after being deformed. However, often these alloys cannot cope with a large number of deformation cycles. Chluba et al. find an alloy that avoids this pitfall, deforming 10 million times with very little fatigue (see the Perspective by James). Such low-fatigue materials could be useful in a plethora of future applications ranging from refrigerators to artificial heart valves. Science , this issue p. 1004 ; see also p. 968

The elastocaloric effect that occurs during the stress-induced martensitic transformation in shape memory alloys is a promising mechanism in view of solid state cooling applications. It also allows for downscaling to feature sizes in the μm range, thus, being attractive for micro-cooling applications using thin film materials. In this study, elastocaloric properties of TiNi and TiNiCu films and their relation to functional fatigue were investigated. Both materials show similar effect sizes, their fatigue behavior is however different. While the temperature change in TiNi degrades by a factor of two within 150 cycles, no significant elastocaloric fatigue was found in TiNiCu.