Origami Crawlers: Exploring A Single Origami Vertex for Complex Path Navigation

The ancient art of origami, traditionally used to transform simple sheets into intricate objects, also holds potential for diverse engineering applications, such as shape morphing and robotics. In this study, it is demonstrated that one of the most basic origami structures–a rigid, foldable degree-four vertex–can be engineered to create a crawler capable of navigating complex paths using only a single input. Through a combination of experimental studies and modeling, it is shown that modifying the geometry of a degree-four vertex enables sheets to move either in a straight line or turn. Furthermore, it is illustrated that leveraging the nonlinearities in folding allows the design of crawlers that can switch between moving straight and turning. Remarkably, these crawling modes can be controlled by adjusting the range of the folding angle's actuation. This study opens avenues for simple machines that can follow intricate trajectories with minimal actuation.