Whole Skin Locomotion Inspired by Amoeboid Motility Mechanisms

Abstract

In this paper, we present a novel locomotion mechanism for mobile robots inspired by the motility mechanisms of single celled organisms that use cytoplasmic streaming to generate pseudopods for locomotion. The Whole Skin Locomotion, as we call it, works by way of an elongated toroid which turns itself inside out in a single continuous motion, effectively generating the overall motion of the cytoplasmic streaming ectoplasmic tube in amoebae. With an elastic membrane or a mesh of links acting as its outer skin, the robot can easily squeeze between obstacles or under a collapsed ceiling and move forward using all of its contact surfaces for traction, or even squeeze itself through holes with diameters smaller than its nominal width by actively changing its cross section diameter making this the ideal locomotion method for search and rescue robots that need to traverse over or under rubble, or for applications where a robot needs to move in and maneuver itself into tight spaces such as for robotic endoscopes. This paper summarizes the many existing theories of amoeboid motility mechanisms, and examines how these can be applied on a macro scale as a novel mobile robot locomotion concept. Four locomotion mechanism models are presented with preliminary experiments and their results, demonstrating the feasibility of the whole skin locomotion strategy.

Toroidal skin drive for snake robot locomotion

“…Anhalt and Herron developed and patented the toroidal skin drive mechanism [20] which is the basis for this work. Ingram and Hong have since developed a mechanism similar in concept to the toroidal skin drive described in this paper [21] [22]. Their device is capable of traveling in a forward direction and maneuvering through small holes and can expand to nominal size.…”

Actuation mechanisms for biologically inspired everting toroidal robots

“…2. These abilities make toroidal robots particularly well suited for the unstructured and highly constrained environments found in medical and search and rescue applications [2]. …”

Mechanics of the Whole Skin Locomotion Mechanism Concentric Solid Tube Model: The Effects of Geometry and Friction on the Efficiency and Force Transmission Characteristics

“…The body of the WSL mechanism is consisted of a toroid shaped skin that either has a solid tube inside (concentric solid tube model, or CST), or is filled with liquid (fluid filled toroid model, or FFT) like that of a common child's toy that is often referred to as a "water worm." The motion of the torus shaped skin is generated by the contraction and expansion of the actuation rings embedded in the skin using several different mechanisms as proposed in [1]. Among these actuation mechanisms, in this paper the analysis of the "rear contractile rings with concentric solid tube" actuation strategy is presented.…”

“…Whole Skin Locomotion (WSL) [1] is a biologically inspired alternative fundamental locomotion mechanism for mobile robots inspired by the motility mechanisms of single celled organisms that use cytoplasmic streaming to generate pseudopods for locomotion. The name comes from the fact that the entire outer surface of the robot, which has a body of a shape of an elongated torus, is used as a surface for traction and that the skin is used for the actuation by cycling through contraction and expansion.…”

“…The motion of these organisms is caused by the process of cytoplasmic streaming where the liquid form endoplasm that flows inside the ectoplasmic tube transforms into the gel-like ectoplasm outer skin at the front, and the ectoplasm outer skin at the end transforms back into the liquid form endoplasm at the rear. The net effect of this continuous ectoplasm-endoplasm transformation is the forward motion of the amoeba [1][2][3].…”