The Mechatronics Research Unit has a long history of working with smart materials, structures and systems. Here we distinguish between "smart" and "intellgent" materials. Smart materials are astute in that they require a simple input stimulus which results in a simple (but different) output without any form of computational interface between input and output, whereas intelligent implies a degree of thinking – i.e. integrated or embedded microelectronics within the material.
There are an enormous amount of smart materials, most of which result in a mechanical output for an electrical, magnetic, thermal or optical input. The mechanical output can be a mechanical movement (actuator) or simply a change is elastic modulus, viscosity, frictional coefficient etc.