SHAPE MEMORY ALLOY ACTUATORS AND CONTROL METHODS

This invention provides stroke-multiplying shape memory alloy actuators and other actuators using electromechanically active materials [collectively referred to in this application as SMA actuators] providing stroke multiplication without significant force reduction, that are readily miniaturizable and fast acting, and their design and use; economical and efficient control and sensing mechanisms for shape memory alloy actuators (including conventional shape memory alloy actuators as well as the stroke-multiplying SMA actuators of this invention) for low power consumption, resistance/obstacle/load sensing, and accurate positional control; and devices containing these actuators and control and sensing mechanisms.