Eel-Inspired Electrohydraulic Soft Swimmer With Programmable Undulatory Gaits
Yi Jin, Imon G. Pranta, Yunteng Cao, Guiyin Xu, Changyong (Chase) Cao
Abstract
Undulatory locomotion in anguilliform swimmers motivates soft robots that are efficient and maneuverable. We present an eel-inspired soft swimmer actuated by liquid-dielectric electrohydraulic actuators (LDEAs) with programmable inter-segment phase for gait control. A resistive-force-theory (RFT) model relates amplitude, frequency, and phase to forward speed and is validated experimentally. Bench tests confirm repeatable bending in air and water. Swimming trials show speed increases with drive frequency, peaking at 22 mm/s at 5 Hz. Phase sweeps indicate that in-phase activation yields the highest forward speed in this three-segment configuration, while traveling-wave gaits provide effective propulsion and enable amplitude-biased turning for left/right maneuvers. Energy metering indicates a minimum dimensionless cost of transport of 54.99. These results demonstrate that LDEAs offer compact, programmable actuation for efficient, controllable soft underwater robots and establish an RFT-guided framework for gait design.
BibTeX
@inproceedings{ral2026_eelinspiredelect,
title = {Eel-Inspired Electrohydraulic Soft Swimmer With Programmable Undulatory Gaits},
author = {Yi Jin and Imon G. Pranta and Yunteng Cao and Guiyin Xu and Changyong (Chase) Cao},
booktitle = {RA-L 2026},
year = {2026}
}