Alternative smart materials

Presently, there are three types of smart materials available, ferroelectric-magnetic and -elastic materials. Prototypes of the three are PZT ceramics, Terfenol-D and Nitinol. Their advantages and disadvantages are well known: Ferroelectric materials are characterized by a large elastic constant and moderate actuation strain, and their dynamical response is excellent. Some antiferroelectrics feature a larger actuation strain. Terfenol-D displays similar mechanical characteristics but its dynamical response is limited by eddy currents. This limitation can be overcome in composites. Nitinol and similar shape memory alloys feature a large elastic constant and actuation strain but suffer from inferior dynamical response which can be overcome in small sections. The ideal actuation material would display a large actuation energy and superior dynamical response. Shape memory type materials display the largest actuation strains known. It is thus natural to inquire into the possibility actuating these alloys with a magnetic field to improve their dynamical performance.