Microwave-Induced Shape-Memory Effect of Chemically Crosslinked Moist Poly(vinyl alcohol) Networks
(1460–1468)Macromolecular Chemistry and Physics 212 #14 (2011)
Du et al of Sichuan University and the China Academy of Building Research, China, showed that chemically crosslinked moist PVA networks have  rapid shape recovery under microwave irradiation, whereas dry samples experience no shape changes when irradiated.  This effect is attributed to the heat created by vibrating water molecules inside the samples that supplies the energy required for shape recovery. The rate of recovery rate is affected not only by the water content in the material but also by the applied microwave power output.  (RDC 7/5/2011)