Shape Memory Motor Directly Powered by Solar Energy for Space Missions

We propose a new motor concept, which is particularly suitable for space missions. The motor made of shape memory alloys can be actuated by sunlight directly. The principle for the operation is similar to the shape memory alloy based heat engines, which were quite popular some years ago. However, unlike those old heat engines, which are driven by hot/cold water, the proposed motor is supposed to be directly driven by solar energy in outer space, taking the advantage of abundant solar energy there, and cooled by self-emission. As such, the motors, upon exposed to sunlight, can rotate automatically, smoothly and continuously without utilizing any electrical power. No solar cell, which is commonly used in space missions, is required. The performance of this kind of motor is investigated numerically by case studies, in terms of angular velocity and output power in this paper.