Introduction to Magnetostrictive Actuators

Magnetostrictive actuators are devices that make use of two evidence of magnetostriction, i.e., the so-called Joule and Wiedemann effects, wirelessly induced by a magnetic field applied to the bare material. The essence itself of those effects, that is the conversion of electric into mechanical energy within the material characteristic, allows the design of relatively simpler devices with respect to the conventional counterparts, electromagnetics, and hydraulic actuators. Magnetostrictives share advantages with other smart materials based actuators but have higher energy density and, being metallic in nature, are less prone to fatigue with respect to piezoelectrics. Their applications span from high precision actuation to vibrations suppression and, recently, in mems technology, thanks to their wireless actuation.