Artificial Life and Robotics

, Volume 20, Issue 3, pp 237–243 | Cite as

Design and control of a ray-mimicking soft robot based on morphological features for adaptive deformation

  • Kenji UraiEmail author
  • Risa Sawada
  • Natsuki Hiasa
  • Masashi Yokota
  • Fabio DallaLibera
Original Article


Underwater tasks are diversified and articulated. The environment in which they must be accomplished is often unconstrained and unpredictable. Operating AUVs assuring safety of the robot and of its surrounding is therefore very difficult. On the other hand, many fishes are able to easily move in the same environments. A crucial factor for this capability is their body, which consists primarily of elastic and soft structures that enable both complex movement and adaptation to the environment. Among the most efficient swimmers we find rays, which show abilities like high speed turning and omnidirectional swimming. In this paper we propose an underwater soft robot based on the morphological features of rays. We mimic both their radially skeletal structure with independent actuators for each bone and the compliance of their fins. This flexibility of the structure provides an adaptive deformation that allows our robot to swim smoothly and safely.


Underwater robot Soft robotics Bio-mimetics Morphological computation Batoid fishes 



This research was supported by “Program for Leading Graduate Schools” of the Ministry of Education, Culture, Sports, Science and Technology, Japan.


  1. 1.
    Chu SW, et al (2012). Review of biomimetic underwater robots using smart actuators. Int J Precis Eng ManufGoogle Scholar
  2. 2.
    Moored, Keith W, et al (2011) Batoid fishes: inspiration for the next generation of underwater robots. Marine Technol Soc JGoogle Scholar
  3. 3.
    Ijspeert AJ (2014) Biorobotics: using robots to emulate and investigate agile locomotion. Science 346(6206):196–203CrossRefGoogle Scholar
  4. 4.
    Webb PW (1994) The biology of fish swimming. In: Mechanics and physiology of animal swimming, p 4562Google Scholar
  5. 5.
    Comas OA (2014) Biomechanics in batoid fishesGoogle Scholar
  6. 6.
    Rosenberger LJ, Westneat MW (1999) Functional morphology of undulatory pectoral fin locomotion in the stingray Taeniura lymma (Chondrichthyes: Dasyatidae). J Exp Biol 202: 3523–3539Google Scholar
  7. 7.
    Low KH, Willy A (2006) Biomimetic motion planning of an undulating robotic fish fin. J Vib ControlGoogle Scholar
  8. 8.
    Takagi K (2006) Development of a rajiform swimming robot using ionic polymer artificial muscles. In: Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and SystemsGoogle Scholar
  9. 9.
    Ikeda M, et al (2014) A pectoral fin analysis for diving rajiform-type fish robots by fluid dynamics. Artificial Life and Robotics, pp 1–6Google Scholar
  10. 10.
    Urai K, et al (2014) Development of a ray-like robot as a next generation bio-inspired autonomous underwater vehicle. In: Aero Aqua Bio-mechanisms (ISABMEC), pp 171–175Google Scholar
  11. 11.
    Yang SB, Qiu J, Han XY (2009) Kinematics modeling and experiments of pectoral oscillation propulsion robotic fish. J Bion Eng 6(2):174–179Google Scholar
  12. 12.
    Galloway KC, et al (2013) Mechanically programmable bend radius for fiber-reinforced soft actuators. In: Advanced Robotics (ICAR), pp 1–6Google Scholar
  13. 13.
    Mosadegh B et al (2014) Pneumatic networks for soft robotics that actuate rapidly. Adv Funct Mater 24(15):2163–2170CrossRefGoogle Scholar
  14. 14.
    Pfeifer R et al (2012) The challenges ahead for bio-inspired’soft’robotics. Communications of the ACM 55(11):76–87CrossRefGoogle Scholar
  15. 15.
    Ziegler M, et al (2011) Varying body stiffness for aquatic locomotion. Robot Autom ICRA, pp 2705–2712Google Scholar
  16. 16.
    Fiazza C, et al (2010) Biomimetic mechanical design for soft-bodied underwater vehicles. In: IEEE OCEANS 2010, pp. 1–7Google Scholar

Copyright information

© ISAROB 2015

Authors and Affiliations

  • Kenji Urai
    • 1
    Email author
  • Risa Sawada
    • 2
  • Natsuki Hiasa
    • 3
  • Masashi Yokota
    • 2
  • Fabio DallaLibera
    • 1
  1. 1.Department of Systems Innovation, Graduate School of Engineering ScienceOsaka UniversityToyonakaJapan
  2. 2.Graduate School of Frontier BiosciencesOsaka UniversitySuitaJapan
  3. 3.Graduate School of Information Science and TechnologyOsaka UniversitySuitaJapan

Personalised recommendations