a device and method are provided combining the thermal and mechanical attributes of two distinct materials : shape memory materials and super - cooled liquids . in one example of the invention , the super - cooled liquid is contained within a shape memory polymer , so that the heat released by the scl when it is mechanically triggered to crystallize itself triggers the shape change of the shape memory polymer . the device is suitable as a reusable warmer , as a dental mold material , in medical applications where reusable heat packs are indicated , particularly for application to difficult contours , and for large deployable structures such as satellite antennae and temporary shelters .