Multistable machines with mechanical sensing capabilities

Multistable structures have emerged as a powerful platform to program sequences and enable new functionalities, ranging from multimodal deformation to logic gates. By programming functionalities in a nonlinear energy landscape, performance can be preserved with fewer components, and without dedicated control of each degree of freedom. Here, we present a strategy to realize multistable structures with a tunable energy landscape to allow for a wide range of deformation sequences. More specifically, our building block consists of a four-bar parallelogram mechanism that connects two rectangular blocks with a pair of identical levers. We span an elastic rubber band between the blocks to create a multiwelled energy landscape that can be tuned by simply varying the anchor point of each elastic band. The stacking of multiple of these building blocks leads even more rich behavior, which is used to create a robotic crawler that combines motion sequencing with mechanical sensing capabilities. As such, this demonstrator can autonomously react to triggers from its the surrounding environment.