  In nature, a variety of limbless locomotion patterns flourish from the small
or basic life form (Escherichia coli, the amoeba, etc.) to the large or
intelligent creatures (e.g., slugs, starfishes, earthworms, octopuses,
jellyfishes, and snakes). Many bioinspired soft robots based on locomotion have
been developed in the past decades. In this work, based on the kinematics and
dynamics of two representative locomotion modes (i.e., worm-like crawling and
snake-like slithering), we propose a broad set of innovative designs for soft
mobile robots through simple mechanical principles. Inspired by and go beyond
existing biological systems, these designs include 1-D (dimensional), 2-D, and
3-D robotic locomotion patterns enabled by simple actuation of continuous
beams. We report herein over 20 locomotion modes achieving various locomotion
functions, including crawling, rising, running, creeping, squirming,
slithering, swimming, jumping, turning, turning over, helix rolling, wheeling,
etc. Some of them are able to reach high speed, high efficiency, and overcome
obstacles. All these locomotion strategies and functions can be integrated into
a simple beam model. The proposed simple and robust models are adaptive for
severe and complex environments. These elegant designs for diverse robotic
locomotion patterns are expected to underpin future deployments of soft robots
and to inspire series of advanced designs.
