SpringerLink
Log in

Soft Gripper using Variable Stiffness Mechanism and Its Application

  • Regular Paper
  • Published:
International Journal of Precision Engineering and Manufacturing Aims and scope Submit manuscript

Abstract

Soft robots have advantages such as low weight and compact size compared to rigid robots. Variable stiffness is one of the key methods of improving the performance of a soft robot. The soft gripper grasps objects of various shapes or sizes based on the variable stiffness. In a previous study, we validated the variable stiffness mechanism where flexible and rigid segments were connected alternately in series. This paper presents a soft variable stiffness gripper that can be used to control the stiffness by pulling tendons. The soft gripper has three variable stiffness structures acting as fingers and the stiffness can be controlled using two motors by winding tendons. To understand the tendency of the stiffness variation and determine the design parameters, a compliant mechanism was developed using a pseudo-rigid-body model (PRBM). The experimental results show that the difference between the lowest and highest stiffness values of the fabricated variable stiffness gripper was 5.6 times the original. Similarly, the difference in the grip** weight was 19 times. Using the experimental results, the variable stiffness gripper can be designed and manufactured based on the required stiffness and used to grip various types of objects.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Abbreviations

E :

Young’s Modulus

G :

Shear Modulus

I :

second moment of inertia

S :

shape factor

R :

radius of cylinder

l :

compressed length

l f :

length of flexible segment

l R :

length of rigid segment

L i :

length of ith segment

γ b :

characteristic radius factor due to bending force

γ m :

characteristic radius factor due to moment

K i :

pseudo torsional spring constant of ith flexible segment

C θb :

parametric angle coefficient by bending force

C θm :

parametric angle coefficient by moment

(EI)’ :

effective bending stiffness of bonded cylindrical layer

θ i :

deflection angle of ith flexible segment

References

  1. Grebenstein, M., Albu-Schäffer, A., Bahls, T., Chalon, M., Eiberger, O., et al., “The DLR Hand Arm System,” Proc. of IEEE International Conference on Robotics and Automation (ICRA), pp. 3175–3182, 2011.

    Google Scholar 

  2. Grebenstein, M., Chalon, M., Friedl, W., Haddadin, S., Wimböck, T., et al., “The Hand of the DLR Hand Arm System: Designed for Interaction,” International Journal of Robotics Research, Vol. 31, No. 13, pp. 1531–1555, 2012.

    Article  Google Scholar 

  3. Butterfaβ, J., Grebenstein, M., Liu, H., and Hirzinger, G., “DLR-Hand II: Next Generation of a Dextrous Robot Hand,” Proc. of IEEE International Conference on Robotics and Automation, pp. 109–114, 2001.

    Google Scholar 

  4. Chi, H.-J., Lee, S.-H., Choi, B.-J., and Choi, H.-R., “Design of a Dexterous Anthropomorphic Robot Hand,” Transactions of the Korean Society of Mechanical Engineers A, Vol. 30, No. 4, pp. 357–363, 2006.

    Article  Google Scholar 

  5. Dollar, A. M. and Howe, R. D., “The Highly Adaptive SDM Hand: Design and Performance Evaluation,” The International Journal of Robotics Research, Vol. 29, No. 5, pp. 585–597, 2010.

    Article  Google Scholar 

  6. Dollar, A. M. and Howe, R. D., “The SDM Hand as a Prosthetic Terminal Device: A Feasibility Study,” Proc. of IEEE 10th International Conference on Rehabilitation Robotics, pp. 978–983, 2007.

    Google Scholar 

  7. Brown, E., Rodenberg, N., Amend, J., Mozeika, A., Steltz, E., et al., “Universal Robotic Gripper Based on the Jamming of Granular Material,” Proceedings of the National Academy of Sciences, Vol. 107, No. 44, pp. 18809–18814, 2010.

    Article  Google Scholar 

  8. Amend, J. R., Brown, E., Rodenberg, N., Jaeger, H. M., and Lipson, H., “A Positive Pressure Universal Gripper Based on the Jamming of Granular Material,” IEEE Transactions on Robotics, Vol. 28, No. 2, pp. 341–350, 2012.

    Article  Google Scholar 

  9. Kim, Y.-J., Cheng, S., Kim, S., and Iagnemma, K., “A Novel Layer Jamming Mechanism with Tunable Stiffness Capability for Minimally Invasive Surgery,” IEEE Transactions on Robotics, Vol. 29, No. 4, pp. 1031–1042, 2013.

    Article  Google Scholar 

  10. Jiang, A., Ataollahi, A., Althoefer, K., Dasgupta, P., and Nanayakkara, T., “A Variable Stiffness Joint by Granular Jamming,” Proc. of ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, pp. 267–275, 2012.

    Google Scholar 

  11. Wall, V., Deimel, R., and Brock, O., “Selective Stiffening of Soft Actuators Based on Jamming,” Proc. of IEEE International Conference on Robotics and Automation (ICRA), pp. 252–257, 2015.

    Google Scholar 

  12. Mitsuda, T., Kuge, S., Wakabayashi, M., and Kawamura, S., “Wearable Haptic Display by the Use of a Particle Mechanical Constraint,” Proc. of 10th Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, pp. 153–158, 2002.

    Google Scholar 

  13. Huh, T. M., Park, Y.-J., and Cho, K.-J., “Design and Analysis of a Stiffness Adjustable Structure Using an Endoskeleton,” International Journal of Precision Engineering and Manufacturing, Vol. 13, No. 7, pp. 1255–1258, 2012.

    Article  Google Scholar 

  14. Ham, K., Han, J., Jeon, J., and Park, Y.-J., “Parametric Study on the Tendency of Stiffness Variation Using Variable Stiffness Mechanism,” Journal of the Korea Academia-Industrial Cooperation Society, Vol. 17, No. 6, pp. 750–758, 2016.

    Article  Google Scholar 

  15. Howell, L. L., “Compliant Mechanisms,” John Wiley & Sons, 2001.

    Google Scholar 

  16. Chalhoub, M. S. and Kelly, J. M., “Effect of Bulk Compressibility on the Stiffness of Cylindrical Base Isolation Bearings,” International Journal of Solids and Structures, Vol. 26, No. 7, pp. 743–760, 1990.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. School of Mechanical Engineering, Sunmoon University, 70, Sunmoon-ro 221beon-gil, Tangjeong-myeon, Asan-si, Chungcheongnam-do, 31460, Republic of Korea

    KiBeom Ham, Jiho Han & Yong-Jai Park

Authors
  1. KiBeom Ham
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jiho Han
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Yong-Jai Park
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Yong-Jai Park.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ham, K., Han, J. & Park, YJ. Soft Gripper using Variable Stiffness Mechanism and Its Application. Int. J. Precis. Eng. Manuf. 19, 487–494 (2018). https://doi.org/10.1007/s12541-018-0059-2

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12541-018-0059-2

Keywords

Search

Navigation