Improving the Loading and Sensing Performance of a Soft Actuator Using an Internal Spine

Soft robots can interact safely with humans and delicate objects, conform to complex shapes, and operate in unstructured environments, making them appealing for a wide variety of applications. However, they are often limited in terms of loading and sensing capabilities. In this paper, we propose a soft actuator integrating a spine designed to improve its overall strength, thus providing a larger bending angle when the actuator is subjected to loads. The spine is stiffer than the main actuator body, thus reducing the yield of the structure when loads are applied. Furthermore, the spine is designed to be mechanically interfaced with a tactile sensor, allowing the deformation of the actuator body to be measured. Experimental results show that the use of the spine improves both the loading and sensing performance compared to a spineless actuator. An additional analysis is also performed to find a proper material to manufacture the spine that provides the best tradeoff between sensing and loading performance.