ABSTRACT
We have combined microscale patterning techniques and origami folding principles at a small size scale, where folding by hand is challenging or impossible. Our structures are first precisely patterned using photolithography to create 2D patterns. The structures are released from the underlying substrate and fold up spontaneously when exposed to triggers such as heat or specific chemicals. We refer to these structures as self-folding and to the methodology as hands-free origami. We have demonstrated this approach by creating microscale structures with up to thousands of folds. Our approach combines rigid origami, a subtype of origami using flat paper and linear fold lines, with kirigami, where folding is combined with paper cutting. Structures can be constructed for a wide range of practical applications; it is possible to use any nonsquare starting pattern and materials such as metals and polymers.
