Actuatable flexible lightweight structure with laminated foam-based soft actuator

Abstract

Recently looking for a possibility different from the conventional robot, various type soft actuator and its application have studied. Especially, pneumatic soft actuators have the advantage of lightweight and powerful. One of the useage of these soft actuators are used as substitute for electric motor in order to actuate the joint of the structure such as link mechanism. Another usage is fusion with flexible structure and actuator. The features of this idea are simplified system, almost all interfaces can be configured as a flexible structure. However, these actuatable flexible structures are made with rubber, silicone, or flexible resin, it is difficult to support its own weight by the affect of the square-cube law, in case of increasing its size. Hence, the actuatable flexible structures are limited the size about1×10^-2~1× 10^-1m size. If the actuatable flexible structures in 1×10⁰ m size, the idea of fusion with soft actuator and flexible structure are expected to provide more new solutions and applications. In this study, as feasibility study, we develop the large size actuatable flexible strucures. We provide LayerCAKE that is Laminated open cell foam and closed cell foam. A cell foam is one of lightweight and flexible material, we use this feature for achive large size actuatable flexible structure. This is actuated by using the phenomenon of open and closed cell foam is a different contraction when these are vacuumed. In this paper, we studied about bending motion model and its velification in experimental way and developed and tested some type of LayerCAKE that provide various motion. Further we developed complex shape LayerCAKE such as a human hand shape. A large actuatable flexible structure of approximately 400 mm size was realized.