Superelasticity

Superelasticity

Superelasticity is a unique property of SMA. If the SMA is deformed at a temperature slightly above its transition temperature, it springs right back into shape. This springy property is called superelasticity. Manufacturers have capitalized on this property finding useful medical and dental applications.

For instance, low temperature nitinol wire is used as orthodontic archwires in braces. The nitinol wire provides a low constant force at human body temperature used to straighten teeth while reducing the need for wire retightening. The transition temperature of these wires are made so that they generate force at the temperature of the human mouth (about 37C (98.6F)).

Supereleastic nitinol tubing are used as surgical catheters. The nitinol catheters can be bent more often than their steel counterparts allowing surgeons to access difficult areas of the human body.