Design of an SMA-based flat actuator with a pattern inspired by amphibian lungs

This research presents the design and implementation of a novel unique actuator, modeled after the shape of an amphibian lung and constructed from Shape Memory Alloy (SMA) wire. By running electric current through the SMA wire, we harness its heat-responsive properties to activate the actuator. This process, known as the Shape Memory Effect(SME), causes the wire to revert to a trained shape, generating a pulling force. The SMA wire was wound around the bolts, which are fixed on the stainless steel plate according to a pattern, and placed in an electric oven to train it. To avoid electrical contact, we insert the patterned SMA wires within a silicone tube. In this research, we utilized a load cell to measure the pulling force of the actuator to verify its usability, and an IMU sensor to measure the actuator’s trajectory. This innovation in actuator design demonstrates significant capability, achieving a free-state deformation up to 110mm and generating a pulling force able to support weights up to 0.7kg. To compare the efficiency of the actuators, we built two more types of actuators and discussed the results of the experiment and future research directions. This research offers expanded potential for SMA-based actuators for a variety of applications.