Improving the response of SMA actuators

Shape memory alloy (SMA) based actuators have a number of attributes which make them useful for robotic applications. Unfortunately their response is relatively slow being limited by the speed with which the SMA can be heated and cooled. This paper describes two novel developments of the basic SMA actuator which improve dynamic performance. To allow rapid heating of the shape memory alloy wire without the danger of over heating an infrared temperature sensor is introduced. Cooling is improved with the aid of a mobile heat sink. These developments are described and preliminary results are presented.