Optimization and Experimental Validation of a Vacuum Suction Cup Operated by Shape Memory Actuators

Abstract Pneumatic Systems, especially those working with compressed air, come with several drawbacks like poor energy efficiency, high level of emission and limited digitalization amongst others. Therefore, there are efforts in industry to replace pneumatics with purely electrical systems. A promising approach in gripping and handling technology is the shape memory alloy (SMA)-based vacuum suction cup, which was first presented at the 2018 SMASIS conference [1]. The working principle relies on an antagonistic SMA-based actuator system in combination with a bistable spring and a silicone membrane. This paper presents the structure and further development of the vacuum suction cup, whose vacuum generation is independent of a temporary or stable airflow. The focus lies on the improvement of the existing mechanics to a more maintenance-friendly design on route to a commercial product. For the implementation new SMA-bundles are created and the wire guides are adjusted accordingly. Besides, several experiments and analyses are carried out to validate the behavior of the mechanics with the new setup using the self-sensing effect. These investigations focus on the effects of varying bundle lengths, lever arms, and damaged bundles on performance. It is shown that the new design approach offers easier handling and robustness in the event of an actuator break.