Experimental study of a bio-inspired robotic morphing wing mechanism actuated by shape memory alloy wires

In this work, a two degree-of-freedom (DOF) mechanism is designed and fabricated that is appropriate for morphing wing applications. The mechanism is developed in such a way that it can undergo different two degrees of freedom so that the wing can have more efficient maneuvers. Among the smart materials Shape Memory Alloy (SMA) actuators are capable of providing more efficient mechanisms in comparison with the conventional actuators due to their large force to stroke ratio, smaller size with high capabilities in limited spaces, and lower weight. As SMA wires have nonlinear hysteresis behavior, their modeling should be implemented in a meticulous way. In this research, after proposing a two DOF morphing wing, a modification is done on a well-known model of SMA, and then the mechanism is modeled. The numerical results of the model simulation are verified against the experimental results using a test setup to validate the proposed model prediction. The proposed mechanism is fabricated in order to verify the model with experimental data. The comparison between theoretical and experimental results shows that the experimental results have good agreement with the theoretical results.