Terradynamics of Monolithic Soft Robot Driven by Vibration Mechanism

In this article, we present a design concept, in which a monolithic soft body is incorporated with a vibration-driven mechanism, called Leafbot. We first report a morphological design of the robot's limbs that facilitates the forward locomotion of our vibration-driven model and enhances the capability of coping with sloped obstacles and irregular terrains. Second, the fabrication technique to achieve such a soft monolithic structure and limb morphology is fully addressed. Third, we clarify the locomotion of the Leafbot under high-frequency excitation via analytical and empirical methods in flat and even surface conditions. The maximum attained velocity in such a condition is 5 body length/ second. Finally, three model designs are constructed, each featuring a different limb pattern. We examine the terradynamics characteristics of three patterns in three pre-defined conditions, i.e., the success rate of overcoming the slope, semi-circular obstacles, and step-field terrains specialized by the rugosity factor. This proposed investigation aims to build a foundation for further terradynamics study of vibration-driven soft robots in a more complicated and confined environment, with potential applications in inspection tasks.