Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a novel robot that takes inspiration from snakes and uses an ancient Japanese paper craft. The new robot is made using kirigami.
Gripping the ground like snakeskin
For the uninitiated, kirigami is a variation of origami that consists of cutting the paper rather than solely folding it. The reimagined robot is an improvement on a first version that used a flat kirigami sheet.
The new robot features a 3D-textured surface capable of gripping the ground just like real snakeskin. It also has a programmable shell that improves the robot's speed and accuracy.
"This is a first example of a kirigami structure with non-uniform pop-up deformations," said Ahmad Rafsanjani, a postdoctoral fellow at SEAS and first author of the paper.
"In flat kirigami, the pop-up is continuous, meaning everything pops at once. But in the kirigami shell, pop up is discontinuous. This kind of control of the shape-transformation could be used to design responsive surfaces and smart skins with on-demand changes in their texture and morphology."
The new research allowed for the control of two properties of the material: the size of the cuts and the curvature of the sheet. By combining these features, the researchers were able to program control localized pop-ups.
"By borrowing ideas from phase-transforming materials and applying them to kirigami-inspired architected materials, we demonstrated that both popped and unpopped phases can coexist at the same time on the cylinder," said Katia Bertoldi, the William and Ami Kuan Danoff Professor of Applied Mechanics at SEAS and senior author of the paper.
"By simply combining cuts and curvature, we can program remarkably different behavior."
The end result is a robot that looks and behaves freakishly like a snake. Now, the researchers are seeking to develop an inverse design model for more complicated deformations.
"The idea is, if you know how you'd like the skin to transform, you can just cut, roll and go," said Lishuai Jin, a graduate student at SEAS and coauthor of the article.
The research was published in the Proceedings of the National Academy of Sciences.