Grasping and manipulation are complex and demanding tasks, especially when executed in dynamic and unstructured environments. Typically, such tasks are executed by rigid articulated end-effectors, with a plethora of actuators that need sophisticated sensing and complex control laws to execute them efficiently. Soft robotics offers an alternative that allows for simplified execution of these demanding tasks, enabling the creation of robust, efficient, lightweight, and affordable solutions that are easy to control and operate. In this work, we explore a new class of soft, kirigami-based robotic grippers, we study their post-contact behavior, and we investigate different cut patterns for their development. We follow an experimental approach in which several designs are proposed and employed in a series of grasping and force exertion tests to compare their capabilities and post-contact behavior.

In the first part of these studies, we investigated extension-based kirigami grippers, which are actuated by pulling on the ends of the structure, extending it.

In a second study on kirigami grippers, we propose a new class of kirigami gripper geometries employing compression-based actuation to create new compact kirigami-based robotic end-effectors. The compression actuation aspect of it fundamentally differentiates these designs from the previous ones available in the literature. The new actuation method results in a geometry that is pushed away from the actuator, increasing the gripper’s reach and facilitating grasping. The study is split into two parts: i) First, we investigate this new class by proposing several working gripper designs with distinct internal cut patterns. These grippers are manufactured by cutting single layers of PET sheets, and their capacities are evaluated through grasping experiments with a set of objects and grasping force measurements. This first part aims to investigate the effects of the different internal cuts, identify the best-performing design, and understand how its cut patterns contribute to its superior performance. ii) Second, we propose a modified version of the best-performing gripper designed with a multi-layer approach and manufactured with hybrid deposition manufacturing (HDM), combining 3D printed PLA sheets sandwiched between silicone layers. This improved, final gripper concept is experimentally tested for its efficacy in grasping challenging everyday life objects.
The experiments validate that the proposed designs can facilitate the development of kirigami-based grippers with excellent grasping performance. The gripper can robustly grasp heavy, hard objects such as a hammer, but also soft, delicate objects such as human hair, egg yolk, and even hold liquids.

As far as we know, this is the first general-purpose gripper capable of “pick-and-placing” liquid. It is interesting to note the human hand also has this capacity.

[3] J. Buzzatto, H. Jiang, J. Liang, B. Busby, A. Lynch, R. V. Godoy, S. Matsunaga, R. Haraguchi, T. Mariyama, B. A. MacDonald, and M. Liarokapis. ”Multi‑Layer, Sensorised Kirigami Grippers for Delicate Robot Grasping and Single‑Grasp Object Identification.” in IEEE Access, vol. 12, pp. 115994‑116012, 2024, doi: 10.1109/ACCESS.2024.3446729

[2] J. Buzzatto, J. Liang, M. Shahmohammadi, S. Matsunaga, R. Haraguchi, T. Mariyama, B. A. MacDonald, and M. Liarokapis, ‘A Soft, Multi‑Layer, Kirigami Inspired Robotic Gripper with a Compact, Compression‑Based Actuation System’, IEEE International Conference on Intelligent Robots and Systems (IROS), 2023.

[1] J. Buzzatto, M. Shahmohammadi, J. Liang, F. Sanches, S. Matsunaga, R. Haraguchi, T. Mariyama, B. MacDonald, and M. Liarokapis, ‘Soft, Multi‑Layer, Disposable, Kirigami Based Robotic Grippers: On Handling of Delicate, Contaminated, and Everyday Objects’, IEEE International Conference on Intelligent Robots and Systems (IROS), 2022.