Bending actuators based on SMA wires – designed for easy integration

Abstract:
Bending actuators based on shape memory alloy (SMA) wires offer a scalable and individual load bearing actuation without any additional mechanical system and relative movements. This enables innovative functions that are compact, lightweight, robust, noiseless and show neither kinks nor gaps. This contribution explains the transfer of affordable macroscopic SMA wires (diameter 0.5 mm) into actuator modules for integrated bending actuation. The flat bending actuators use several parallel-arranged SMA wires to ensure a compact and lightweight design. There are two major challenges on integrating shape memory elements in an application product. The two topics of mechanical and electrical connection are solved within the actuator modules and furthermore these are designed for an easy integration in various products. The actuator modules vary in size, deflection and load capability in a wide range, depending on the costumer’s requirements. The contribution explains the different connection methods together with application examples like a self-sufficient rim ventilation, an active underfloor panel and high performance CFRP materials. Also the result of cycling test in the newest configuration is shown together with the resistivity measurement revealing the potential for self-sensing-based control even for high cycle applications.