Development of a compliant, high-efficiency and bio-inspired snake-like swimming robot

The work reported in this paper addresses the development of soft bodied robots for adaptive interaction with the environment and for increased energy efficiency, thanks to intrinsic body properties and to storage of mechanical energy. Swimming locomotion has been chosen as elective field, because of an active research framework (European research project “Lampetra” [1] on eel-like artefacts) and because of an easy-to-tackle configuration (i.e. buoyancy eliminating gravity). A novel, muscle-like actuation is presented and experimentally validated through a prototype of flexible, high-efficiency swimming robot. Several works on the development of flexible robots have been described in literature, such as inchworms or earthworms [2-3], snakes [4] and caterpillars [5]. In particular, regarding the implementation of autonomous fish-like robots, some articles were published focusing on innovative actuation like shape memory alloys (SMA) [6], piezoelectric materials [7], electroactive polymers [8] and pneumatics [9]. A previous work on a flexible bioinspired robot [10] has been presented by SSSA, based on solenoid actuators. The purpose of that work was to implement a wired robotic platform able to replicate bioinspired actuation in terms of force-displacement relation, but energy efficiency was poor and the system was wired. Conversely a wireless fish-like robot is considered in this paper, exploiting a novel actuation concept with both muscle-like actuation and high energy efficiency.