Analysis of Variable-Stiffness Soft Finger Joints

  • Daniel Cardin-CatalanEmail author
  • Angel P. del Pobil
  • Antonio Morales
Conference paper
Part of the Advances in Intelligent Systems and Computing book series (AISC, volume 867)


This paper addresses the problem of designing an artificial finger with variable stiffness in its joints. Our approach is based on the principle of combining different means of actuation. Two different versions of variable-stiffness joints are presented and used in the design and manufacturing of three prototypes of gripper fingers. Diverse material configurations are used in order to determine which are the distinctive capabilities of each one and how they differ. In order to test the fingers we built a test bench that allows us to measure the movement of the tendon-driven actuation, the pressure of air actuation and the force that is deployed in the tip of the finger. Several tests are made to measure the relation between the actuation input and the force exerted by the fingertips. Our results suggest that the best mechanism to achieve variable stiffness in the joints is a soft-rigid hybrid finger.


Variable stiffness Soft robotics Grippers 



This paper describes research done at UJI RobInLab. Support for this research was provided by Ministerio de Economa y Competitividad (DPI2015-69041-R).


  1. 1.
    Al Abeach, L.A.T., Nefti-Meziani, S., Davis S.: Design of a variable stiffness soft dexterous gripper. Soft Robot. J. 4(3), 274–284 (2017)CrossRefGoogle Scholar
  2. 2.
    Pfeifer, R., Lungarella, M., Iida, F.: The challenges ahead for bio-inspired soft robotics Commun. ACM 55(11), 76 (2012)CrossRefGoogle Scholar
  3. 3.
    Laschi, C., Rossiter, J., Iida, F., Cianchetti, M., Margheri, L.: Soft Robotics: Trends, Applications and Challenges Biosystems & Biorobotics, vol. 17. Springer (2017)Google Scholar
  4. 4.
    Hughes J., Culha U., Giardina F., Guenther F., Rosendo A., Iida, F.: Soft manipulators and grippers: a review. Front. Robot. AI 3, 69 (2016)Google Scholar
  5. 5.
    Rus D., Tolley T.: Design, fabrication and control of soft robots. Nature 521(7553), 467–475 (2015)CrossRefGoogle Scholar
  6. 6.
    Culha, U., Hughes, J., Rosendo, A.L., Giardina, F., Iida, F.: Design principles for soft-rigid hybrid manipulators. Biosyst. Biorobotics 17, 87–94 (2017)CrossRefGoogle Scholar
  7. 7.
    Yufei, H., Tianmiao, W., Xi, F., Kang, Y., Ling, M., Juan, G., Li, W.: A variable stiffness soft robotic gripper with low-melting-point alloy. In: Proceedings of the 36th Chinese Control Conference, pp. 6781–6786 (2017)Google Scholar
  8. 8.
    Yang, Y., Chen, Y.: 3D printing of smart materials for robotics with variable stiffness and position feedback. In: IEEE/ASME International Conference Advanced Intelligent Mechatronics, AIM, pp. 418–423 (2017)Google Scholar
  9. 9.
    Memar, A.H., Mastronarde, N., Esfahani, E.T., Design of a novel variable stiffness gripper using permanent magnets. In: IEEE International Conference Robotics and Automation, pp. 2818–2823 (2017)Google Scholar
  10. 10.
    Li, Y., Chen, Y., Yang, Y., Wei, Y.: Passive particle jamming and its stiffening of soft robotic grippers. IEEE Trans. Robot. 33(2), 446–455 (2017)CrossRefGoogle Scholar
  11. 11.
    Firouzeh, A., Paik, J.: An under-actuated origami gripper with adjustable stiffness joints for multiple grasp modes. Smart Mater. Struct. 26(5), 055035 (2017)CrossRefGoogle Scholar
  12. 12.
    Manti, M., Cacucciolo, V., Cianchetti, M.: Stiffening in soft robotics: a review of the state of the art. IEEE Robot. Automat. Mag. 23, 93–106 (2016)CrossRefGoogle Scholar
  13. 13.
    Hogan, N.: Adaptive control of mechanical impedance by coactivation of antagonist muscles. IEEE Trans. Automat. Control 29(8), 681–690 (1984)CrossRefGoogle Scholar
  14. 14.
    Migliore, S., Brown, E., DeWeerth, S.: Biologically inspired joint stiffness control. In: IEEE International Conference on Robotics and Automation, pp. 4508–4513 (2005)Google Scholar
  15. 15., December 2017
  16. 16.
    Townsend, W.T.: The Barrett Hand grasper-programmably flexible part handling and assembly. Ind. Robot Int. J. 10(3), 181–188 (2010)CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Daniel Cardin-Catalan
    • 1
    Email author
  • Angel P. del Pobil
    • 1
  • Antonio Morales
    • 1
  1. 1.Robotic Intelligence LaboratoryUniversitat Jaume ICastellón de la PlanaSpain

Personalised recommendations