Actuator materials convert input energy to mechanical out-put energy. Electromagnetic actuation, whether in motors, voice coils, or solenoids, has dominated electrical actuator technology for most of the last century. Other commercial ac-tuator technologies such as piezoelectrics have (although important) generally been confined to niche applications such as acoustics. Electromagnetic actuation may, however, lose its dominance, as several new actuator materials may compete directly with electromagnetics in both performance and cost for a wide range of applications.[1±6]