Japanese Paperfolding Inspired New Shape-Changing Metamaterials

University of Bristol Engineers have developed a new shape-changing material using Kirigami – Origami’s big brother. As well as just folding paper, the ancient Japanese art involves cutting it; which usually would create a weakness, but in this case gives the material the ability to be formed into complex 3D shapes with a broader choice of geometries than Origami allows.

Metamaterials are a class of material which are engineered to produce properties which don’t occur naturally. They are currently used to make artificial electromagnetic and vibration absorbers, and high-performance sensors.

The research, which has been developed within a PhD program run by the University’s EPSRC Centre for Doctoral Training in Advanced Composites for Innovation and Science (ACCIS CDT), has been published in Scientific Reports.

PhD student Robin Neville has developed the technique using Kirigami, and creates mechanical metamaterials which change shape seamlessly. These exhibit large variations in mechanical performance with small geometry changes, and it can be adapted to modify its configuration by using mainstream actuation mechanisms.

These can also be produced using off-the-shelf thermoplastics or other thermoset composite materials, and can be upgraded by embedding different sensing and electronics systems, to obtin fully integrated smart shape-changing structures.

The Professor of Smart Materials and Structures in the Department of Aerospace Engineering and ACCIS, Fabrizio Scarpa, said, “Mechanical metamaterials exhibit unusual properties through the shape and deformation of their engineered subunits. Our research presents a new investigation of the kinematics of a family of cellular metamaterials based on Kirigami design principles. This technique allows us to create cellular structures with engineered cuts and folds that produce large shape and volume changes, and with extremely directional, tuneable mechanical properties.”

Robin Neville, PhD student, added: “By combining analytical models and numerical simulations we have demonstrated how these Kirigami cellular metamaterials can change their deformation characteristics. We have also shown the potential of using these classes of mechanical metamaterials for shape change applications like morphing structures.”

In the future, these Kirigami-based metamaterials could be used in robotics, morphing structures for airframe and space applications, microwave and smart antennas.


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BDC 299 December 2022