Incredible progress has been made by researchers to kirigami. This centuries-old Japanese art form is a splendid fusion of artistic creativity and scientific engineering practices. A new research published in Physical Review Letters uncovers a powerful new geometric approach. This inverse design strategy removes key barriers in the inverse design process to generate kirigami structures. Senior author Damiano Pasini and former Ph.D. student Chuan Qiao head this research. They investigate techniques to control the overall deformation of kirigami by changing the shapes of its turning elements, enabling exciting new creative usages in physics, engineering disciplines, and material science.
Kirigami is the Japanese art of cutting and folding paper to produce elaborate three-dimensional shapes. This ancient art has gained attention in modern scientific research for its potential to develop new materials and devices, including robotic systems. Through physical experiments and computational modeling, the researchers’ key interest was in understanding how the geometry of rotating units in kirigami could be controlled to obtain desirable deformation patterns. Their objective was to produce designs that preclude the use of detailed numerical techniques.
The Research Framework
The team went with a unit cell approach. More generally, they looked at how arbitrary unit arrangements that employ triangular shapes, which would in practice likely be rotatable, deform when stretched. Their results uncover an important connection between the amount of strain imposed on these units and the resulting shear deformation. This relationship is seen in deployed kirigami structures. With reducing scale of the rotating units, the final morphology of the kirigami opens up further. It now fosters an active, ever-increasing shift in its architecture.
“The key notion is that the shear strain applied to the initial rotating units, which shrink horizontally when we move from the left to the middle sketch, is in the opposite direction of the shear strain of the deployed triangle kirigami, which, in contrast, expands horizontally,” – Damiano Pasini
Considering the influence of deployment mechanics, the researchers evaluated unintended shape change by calculating the side lengths and internal angles of individual triangular units. This analysis uncovered a strong geometric correspondence that can be used in inverse design. This revelation gives designers the power to tune specific kirigami patterns by merely altering the geometry of their rotatable modules.
Implications and Applications
The impact of this research goes far beyond academic study. The team’s novel geometric design approach has the potential to empower engineers and researchers to tackle multifaceted challenges in a myriad of disciplines. Finding rapid design methods for kirigami structures opens up the potential for increased applications. These advances have wide-reaching applications in spaces including robotics, soft materials and adaptive systems.
“Our method can now forego any numerical computations and program the shear deformation of a kirigami specimen at will in a swift, versatile manner,” – Pasini
The team of researchers were keen to stress that their work should be viewed as an organic progression of preexisting studies into kirigami dynamics. Their overall goal is to discover an important relationship between the geometry of rotating units and the operation geometries of kirigami metamaterials. Based on this finding, future designs will be simpler to implement.
“This work brings ground-rule insights into morphing matter with rotating units and offers an intuitive, firsthand geometric route for the swift design of complex kirigami,” – Pasini
A Path Forward
As the first author, Chuan Qiao’s contributions are a testament to the collaborative and team-oriented nature of this research. Throughout his Ph.D. studies, he narrowed his focus to documenting interactions in thin shells. Under Pasini’s guidance, he studied the anisotropic morphing of kirigami. Equipped with this foundational knowledge, Qiao’s research has since made breakthroughs that revolutionize the way researchers can design kirigami.
“With these questions in mind, our goal then became twofold: to unveil the fundamental relation between the shape of the rotating units and the shape of the deployed kirigami and to leverage such a relation for the design of kirigami that foregoes the use of fairly sophisticated numerical methods currently used in the literature,” – Pasini
The team of researchers predict that their findings will lead to more discovery about other kirigami patterns and the role they play in different fields. The same conclusions can be made by studying quadrilateral kirigami, demonstrating the power and breadth of their novel methodology.