A radiant energy-powered shape memory alloy actuator

This paper will present the development of an innovative actuator using a shape memory alloy (SMA) that is powered by available radiant energy in the space environment. Currently, self-contained or tethered power supplies provide the energy source for actuators in space applications. These can be costly, heavy and require regular maintenance and/or refueling. Ideally an actuator for space applications should have a high power density, be able to operate with little interference from its power source and maintain a low operating cost. Shape memory alloys are materials that recover internal strain with the addition of heat, thus changing thermal energy to mechanical energy. Because of this, they are known as thermomechanical motors. These materials can be thermally actuated by a number of means with the primary conventional approach based on resistive heating. Radiant energy, while typically impractical for use under normal circumstances, is a significant and abundant energy source in space and can be directed to control phase transition in a SMA material. This paper will describe the development of a radiant-heat driven SMA actuator, presenting a simple actuator model and prototype. The paper will also compare this actuator against other SMA-based actuators. [Copyright &y& Elsevier]