Poisson Induced Bending Actuator for Soft Robotic Systems

This article deals with a novel active bending soft body that uses metamaterials and combines soft behavior, integrated actuation, low complexity, and a high density of producible forces and moments. The presented concept consists of a tube-like structure with tailored, unconventional material properties, which enable the generation of a bending deformation and/or moment when circumferential stress and/or strain is induced. Circumferential actuation can be generated by a difference in pressure between the internal and external surface of the tube or, alternatively, by distributed expansion actuators that act radially or tangentially (e.g., shape memory wires). In addition to an analytical model, this article also presents a design procedure and deals with the implementation of the proposed concept in a functional prototype and its experimental characterization.