Design and Fabrication of a Novel SMA Spring Actuated 2DOF Orientating Mechanism

This paper presents design and fabrication of a new 2DOF friction-locked mechanism which is actuated by shape memory alloy (SMA) springs. The proposed mechanism can be used in car side-mirrors. It is also a good choice for tiling 3D surfaces like solar furnaces. The system contains an unprecedented friction-locking mechanism to eliminate its dependency on power when a desired orientation is obtained. Moreover, due to unique features of SMA springs i.e. high output force to weight ratio as well as low power consumption and price compared to conventional DC motors, SMA springs are chosen to actuate the system. A prototype of the mechanism is fabricated in order to experimentally evaluate its functionality. Test results show that shape memory springs successfully manipulate the top plate to a desired position. In addition, when system reaches favorable position and input power is cut off, it successfully subsists on its state without power input.