Date of Award
Master of Science (MS)
Soft pneumatic actuators have many applications in robotics and adaptive structures. Traditionally, these actuators have been constructed by wrapping layers of reinforcing helical fibers around an elastomeric tube. This approach is versatile and robust, but it suffers from a critical dis-advantage: cumbersome fabrication procedures. Wrapping long helical filaments around a cylindrical tube requires expensive equipment or excessive manual labor.
To address this issue, we propose a new approach towards designing and constructing pneumatic actuators by exploiting the principle of kirigami, the ancient art of paper cutting. More specifically, we use “kirigami skins”—plastic sleeves with carefully arranged slit cuts—to replace the reinforcing helical fibers.
This paper presents an initial investigation on a set of linear extension actuators featuring kirigami skins with a uniform array of cross-shaped, orthogonal cuts. When under internal pressurization, the rectangular-shaped facets defined by these cuts can rotate and induce the desired extension motion. Through extensive experiments, we analyze the elastic and plastic deformations of these kirigami skins alone under tension. The results show strongly nonlinear behaviors involving both in-plane facet rotation and out-of-plane buckling. Such a deformation pattern offers valuable insights into the actuator’s performance under pressure. Moreover, both the deformation characteristics and actuation performance are “programmable” by tailoring the cut geometry. A computational model was developed to predict the deformation pattern of the kirigami skins. This study lays down the foundation for constructing more capable Kirigami-skinned soft actuators that can achieve sophisticated motions. Additional design variables were implemented into the kirigami patterns to generate for rectangular and rhomboid elements. A kirigami skin defined by these parameters can produce a wide range of actuation patterns.
Iannucci, Steven Michael, "Utilization of Kirigami Skins as a Method of Creating Bespoke Soft Pneumatic Actuators" (2020). All Theses. 3458.