RoboHeart: A Bi-Directional Zipping Actuator

Widespread adoption of soft robotic technologies is held back by the limitations of existing soft robotic actuators. One cause of the limited performance of soft actuators is their uni-polar stroke, which means only part of the work-cycle is powered. In this work, we introduce RoboHeart, a bi-directional compliant smart actuator. RoboHeart consists of two spring-steel strips covered with PVC insulation, pre-bent into a heart shape and is driven by dielectrophoretic zipping. Here, we perform isotonic and isometric characterisation of RoboHeart performance, demonstrating work output of 17 mJ (expansion) and 18 mJ (contraction) and power of 1.5 mW (expansion) and 2 mW (contraction). We then confirm the practical application of RoboHeart by demonstrating a 10-RoboHeart ring configuration capable of gripping a range of objects as they are lifted. We also demonstrate bidirectional control of actuation using three separate control channels. We believe that RoboHeart represents a step towards high-performance soft actuators and technologies.