Soft-Skin Actuator Capable of Seawater Propulsion based on MagnetoHydroDynamics

Mutsuki Matsumoto, Yu Kuwajima, Hiroki Shigemune

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


Underwater robots have a variety of potential uses, including marine resource research, ecological research, and disaster relief. Most of the underwater robots currently in practical use have screw propulsion systems, which have several noises, collision, and entrainment problems. There is a lot of research on underwater robots using soft actuators to solve these problems. However, current soft actuators have disadvantages, such as the need for special fluids, pressure sources, and high voltage circuits. Therefore, we have developed a soft-skin actuator based on magnetohydrodynamics (MHD). The soft-skin MHD actuator is made of soft material and the structure is prepared as thin, which allows it to attach to the surface of an object, including curved surfaces, to provide the object with a propulsive function in the sea. Since it has no moving parts, it does not generate mechanical noise, and there is no danger of entrapment. Because it can pump seawater directly, it does not require a special working fluid, and its structure is simple and easy to miniaturize. This paper investigates the thrust and power consumption of the developed soft-skin MHD actuator when attached to a flat surface. As a result, we obtained a thrust of 1.37 mN from a single soft-skin MHD actuator with a maximum power of about 140 W. We also measured the thrust force by attaching it to a curved surface. We obtained a higher thrust on a curved surface by adjusting the crossing of the magnetic field and the current than when using a flat surface. We developed an untethered robot that can remove oil from the sea using soft-skin MHD actuators. We demonstrated the adaptability of the soft-skin MHD actuator by attaching it to a commercial underwater camera weighing about 253.5 g and providing propulsion.

Original languageEnglish
Title of host publicationIEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2022
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages7
ISBN (Electronic)9781665479271
Publication statusPublished - 2022
Event2022 IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2022 - Kyoto, Japan
Duration: 2022 Oct 232022 Oct 27

Publication series

NameIEEE International Conference on Intelligent Robots and Systems
ISSN (Print)2153-0858
ISSN (Electronic)2153-0866


Conference2022 IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2022

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Software
  • Computer Vision and Pattern Recognition
  • Computer Science Applications


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