Magnetostrictive actuators

Abstract

Engineers have found that it is possible to develop a simple, highly-reliable linear-motor-based actuator using materials that exhibit magnetostriction effect. One such material is Terfenol-D which changes its shape when exposed to magnetic fields. Repeated propagating waves of magnetic flux produces a useful stroke and force output which can be used to power peristaltic linear motors. The Smart Wings Program of the US Defense Department aims to develop actuators which use this type of linear motors. These actuators may be used in various applications such as fine-tuning the shape of the airfoil cross section of an aircraft wing in flight and reduce aerodynamic drag.