Katia Bertoldi, William and Ami Kuan Danoff Professor of Applied Mechanics, Harvard John A. Paulson School of Engineering
Kirigami-Inspired Metamaterials - from Morphable Structures to Soft Robots
In the search for materials with new properties, there have been great advances in recent years aimed at the construction of mechanical systems whose behaviour is governed by structure, rather than composition. Through careful design of the material’s architecture, new material properties have been demonstrated, including negative Poisson’s ratio, high stiffness-to-weight ratio and mechanical cloaking. While originally the field focused on achieving unusual (zero or negative) values for familiar mechanical parameters, more recently it has been shown that non-linearities can be exploited to further extend the design space.
In this talk I will focus on kirigami-inspired metamaterials, which are produced by introducing arrays of cuts into thin sheets. First, I will demonstrate that instabilities triggered under uniaxial tension can be exploited to create complex 3D patterns and even to guide the formation of permanent folds. Second, I will show that such non-linear systems can be used to designs smart and flexible skins with anisotropic frictional properties that enables a single soft actuator to propel itself. Finally, I will focus on bistable kirigami metamaterials and show that they provide an ideal environment for the propagation non-linear waves.