Mechanical programmable design of soft pneumatic actuators with kirigami patterns to generate expanding, bending and twisting motions.

This paper presents the influence of cuts inspired by kirigami art on the outer surface of a soft actuator with cylindrical geometry. Both the kirigami pattern and orientation were varied to achieve expanding, bending, and twisting motions. Two symmetric kirigami patterns are presented, i.e., cells and stripes, in a horizontal, vertical, and tilted configurations, respectively. We also present the tensile response of the kirigami sheets by using the finite element method (FEM). Then, we show that the soft actuator expands, bends or twists when kirigami patterns are wrapped around it. All actuators were analyzed by performing FEM simulations to evaluate the effects of kirigami patterns on the actuator performance. Among the obtained variants of the expanding and bending actuators, the striped pattern provided the best performance for both motions. We show how the number of cuts and the relationship between the gaps affect the expanding performance. For the twisting motion, we obtained two variants; we present the influence of the change of the inclination angle for both patterns, i.e., cells and stripes. The actuators that presented the best performance for each motion were built; a manufacturing process using the casting technique is described. The validation of the hardware by computer vision is presented. [ABSTRACT FROM AUTHOR]