Sponge-Based Mobile Soft Robot with Multimodal Locomotion

In recent years, mobile soft robots have been widely studied because of their simple structure and friendly interaction. However, most mobile soft robots have only one locomotion mode, such as crawling or rolling, which can't adapt to unstructured environments. In this paper, we propose a novel Sponge-based mobile soft robot with multimodal locomotion. This is the first mobile soft robot with multimodal locomotion based on sponges. The proposed sponge-based mobile soft robot comprises 12 edge actuators and 8 corner actuators. By regulating the vacuum pressure in edge actuators and corner actuators, the proposed robot can crawl or roll. The proposed robot can locomote in unstructured environments by choosing a suitable locomotion mode. In this paper, the shrinkage of edge actuators is examined, and the deflection angle of two kinds of locomotion modes is compared. According to the experiment on the shrinkage of edge actuators, as the vacuum pressure increases, the shrinkage of edge actuators increases and finally reaches a steady state. The deflection angle experiment shows that crawling is more stable than rolling, and rolling requires less cycle than crawling at a certain distance.