Terrestrial snakes, aquatic snakes, and sandfish lizards are observed to adopt different configurations for locomotion, although they all employ the snake-like un-dulatory wriggling motion. Here we show that these differences may be dominated by the movement and energy efficiencies imposed by mechanical deformation and interaction with environments. Based on a slender soft beam model, a systematical framework is developed to explore and compare the movement and energy efficiencies of the snake-like lateral undulation in terrestrial, aquatic and sand environments. Indeed, it is found that the locomotion configuration of the soft body is highly relevant to the efficiency factors. Optimal un-dulatory configurations are obtained for each environment, which are qualitatively consistent with the biological ones. The present study reveals the mechanism behind the locomotion adaptation of the un-dulatory wriggling motion for navigating through different environments, which sheds light on developing amphibious/all-terrain soft robots, while, at the same time, broadens our cognition of nature's strategies for locomotion. © 2021 Elsevier Ltd
Bibliographical noteThis work was supported by the National Natural Science Foundation of China (12002271, 11902226, 11872302), Xi'an Science and Technology Plan Project, China (2019220914SYS024CG046), and Earth Engineering Center and Center for Advanced Materials for Energy and Environment at Columbia University.
- Movement and energy efficiency
- Soft robot
- Undulatory locomotion