Rational design of reconfigurable devices and architected materials

Abstract
Metamaterials are rapidly arising at the frontier of science due to their unusual properties obtained by structure rather than chemistry. Using origami, programmable metamaterials have been previously created from two-dimensional sheets through folding along predefined creases. In particular, the miura-ori fold pattern, which has a single degree of freedom, has proven to be promising in the design of solar panels for space deployment, flexible medical stents, 3D cell laden microstructures, and flexible electronics. There are however many more origami patterns that can be used to design deformable 3D structures. Here, we are inspired by snapology, a type of modular unit-based origami in which paper ribbons are used to create complex geometric extruded polyhedra. We found that some of the resulting geometries are stiff and almost rigid, while others have multiple degrees of freedom and can be easily deformed. We use these foldable geometries as a building block to form prismatic programmable metamaterials whose shape and volume can be controlled. Moreover, we explore a distributed actuation approach to reprogram the shape of the metamaterial by embedded actuation. Since the transformation modes described for these materials operate independently of the object’s macro-scale external geometry, this metamaterial can be machined into any desired architecture. For example, it can be used to design millimeter-scale reconfigurable tubular stents that can easily fit through small, as well as centimeter-scale foldable chairs and meter-scale deployable domes. Therefore, we believe that our approach can result in simplified routes for the design of transformable structures and devices.