Using an ancient art form to improve robotic technology

Kirigami is an ancient art form that involves strategically configuring cuts to release constraints in sheet materials and allow buckling and folding. This process can induce shape transformations in the planar or nonplanar geometry and significantly increases the kinematic degree of freedom, producing intricate, three-dimensional art.

Kirigami’s beautiful designs also prove to be highly functional. Wang et al. combined the delicate art of kirigami with hard magnetic actuation to design untethered soft robots which exhibit controllable locomotion, active and passive environmental adaptabilities, and multifunctionalities.

Controllable locomotion is a key component of robotics. While conventional rigid robots require high-power engines and transmission systems to achieve locomotion, soft robot motion depends on flexible material and functional design. However, controllable locomotion of magnetic soft robots is limited because of the highly specialized equipment and skilled operations necessary for use.

“Introducing the kirigami structure enables diverse shape morphing, which leads to various locomotion modes,” said author Dong Wang.

The authors developed a two-module, soft robot with slit-perforated kirigami patterns and embedded hard magnetic disks in each facet. The robot actively adapted when it encountered obstacles. Other functionalities were also observed, including walking, crawling, flapping, swimming, carrying large objects, acting as a remote circuit switch, removing obstacles, and turning circularly.

“The kirigami soft robot is not confined to specific manufacturing methods or feature sizes, significantly simplifying the design and manufacture of magnetic soft robots,” said Wang. “The design method opens up a broad appeal in medical and industrial settings, such as remote circuits, biomedical engineering, and drug delivery.”

Source: “Untethered kirigami soft robots with programmable locomotion,” by Jinqiang Wang, Ruichen Wang, Zixiao Zhu, Kun Zhou, and Dong Wang, Applied Physics Reviews (2023). The article can be accessed at https://doi.org/10.1063/5.0155355 .