Many implantable biomedical devices could benefit from a material with a strongly temperature-dependent modulus. Catheters made from such a material could be inserted as a stiff plastic, and upon reaching body temperature, would soften dramatically to minimize erosion of adjacent tissue. Sutures could be stiff during placement in an incision, heated slightly to form a shape to hold the suture in place, and then cooled. A new family of materials known as softenable, shape-memory thermoplastics have a distinct and adjustable thermal transition that produces a dramatic change in modulus at a predetermined temperature (range)