This image shows bending behavior. (a) Synclastic curvature in the closed configuration; (b) cylindrical curvature in the open rec configurations; (c) an open rec specimen folder double. (CREDIT: University of Bristol)
The University of Bristol engineers have developed a new shape-changing metamaterial. This metamaterial was created using an ancient Japanese art known as Kirigami. In Kirigami, 3D shapes are obtained by cutting and folding paper.
Metamaterials are a group of materials that are engineered to develop properties that do not occur naturally. Presently, metamaterials are utilized to make high-performance sensors, and artificial electromagnetic and vibration absorbers.
Kirigami has a wider selection of geometries than 'classical' origami, and can be used to convert two-dimensional sheet materials into complex three-dimensional shapes.
The research findings of the study that took its origin in a PhD program administered by the University's EPSRC Centre for Doctoral Training in Advanced Composites for Innovation and Science (ACCIS CDT), have been recently featured in Scientific Reports.
This kind of mechanical metamaterial developed by PhD student Robin Neville can be reconfigured using mainstream actuation mechanisms. This metamaterial developed using Kirigami technique portrays large differences in mechanical performance with small geometry changes and can also change shape seamlessly.
Thermoset composite materials or off-the-shelf thermoplastic can also be used to produce the Kirigami metamaterial. Various electronic systems and sensing systems can be embedded into them to get a completely integrated smart structure that can change shapes.
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, tunable mechanical properties.
Fabrizio Scarpa, Professor, University of Bristol
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 future, the Kirigami metamaterial will develop applications in robotics, morphing structures for space and airframe applications, smart antennas and microwave.