Discrete actuators are devices that transform active material characteristics for high stroke applications.Driving factors in the designs are: Mass Efficiency, Energy Density, Discrete actuators considered are bender, diamond, x-frame actuator, pyramid.
Other actuators considered include a simple lever actuator, and a stack actuator coupled with an extension twist composite tube. Trade studies indicate X-Frame actuator yields highest mass efficiency of devices considered. Current research focused on placing X-Frame actuator within helicopter rotor blade.