Skip to main content

Design and Analysis of Artificial Muscle Robotic Elbow Joint Using Shape Memory Alloy Actuator


Artificial muscle is one of the more prominent topics in modern robotics as it can be applied to robotic arms, electric vehicles and wearable robots (Shahinpoor et al. in Smart Mater Struct 7:15–30, 1998; Jani et al. in Mater Des 56:1078–1113, 2014). The advantages of Shape Memory Alloy (SMA) artificial muscle are lightness and high energy density. The high energy density allows the actuator to make powerful motions. Meanwhile, SMA wire contracts 6% of its length, which means that the required displacement cannot be achieved by a simple connection. To resolve these disadvantages, the SMA wires are coiled in a diamond-shaped structure. If the electric current is given by contracting wires in the longitudinal direction, the actuator can exert force and displacement in the diagonal direction. As the crossed tendon finds its minimal length when actuated, the rotation angle converges to 90°. Parameters related with the rotating motion were selected, such as SMA wires’ diameter and length, distance between the crossed part and elbow part, size of the diamond-shaped structure, friction, etc. To determine the maximum force of the actuator, a graphical method was used, which is similar to the yield strength determination (0.2% offset). Because the robotic elbow joint is connected by the tendon, the connections between links are flexible, and without motor it does not generate any sound or noise during operation. The robotic elbow joint using the SMA actuator is designed and analyzed, which can rotate 86.7° and generates maximum 56.3 N force.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13


  1. 1.

    Shahinpoor, M., Bar-Cohen, Y., Simpson, J. O., & Smith, J. (1998). Ionic polymer-metal composites (IPMCs) as biomimetic sensors, actuators and artificial muscles: a review. Smart Materials and Structures,7, 15–30.

    Article  Google Scholar 

  2. 2.

    Hunter, I. W., & Lafontaine, S. (1992). A comparison of muscle with artificial actuators. In: IEEE, solid-state sensor and actuator workshop 5th technical digest.

  3. 3.

    Chu, W. S., et al. (2012). Review of biomimetic underwater robots using smart actuators. International Journal of Precision Engineering and Manufacturing,13, 1281–1292.

    Article  Google Scholar 

  4. 4.

    Binayak Bhandari, Gil-Yong Lee, Sung-Hoon Ahn, (2012) A review on IPMC material as actuators and sensors: Fabrications, characteristics and applications. International Journal of Precision Engineering and Manufacturing 13(1):141–163

    Article  Google Scholar 

  5. 5.

    Brinson, L. C., & Huang, M. S. (1996). Simplification and comparisons of shape memory alloy constitutive models. Journal of Intelligent Material Systems and Structures,7, 108–114.

    Article  Google Scholar 

  6. 6.

    Elahinia, M. H., & Ahmadian, M. (2005). An enhanced SMA phenomenological model: The shortcomings of the existing models. Smart Materials and Structures,14, 1297–1308.

    Article  Google Scholar 

  7. 7.

    Elahinia, M. H., & Ahmadian, M. (2005). An enhanced SMA phenomenological model: The experimental study. Smart Materials and Structures,14, 1309–1319.

    Article  Google Scholar 

  8. 8.

    Brinson, L. C. (1993). One-dimensional constitutive behavior of shape memory alloys: Thermomechanical derivation with non-constant material functions and redefined martensite internal variable. Journal of Intelligent Material Systems and Structures,4, 229–242.

    Article  Google Scholar 

  9. 9.

    Lagoudas, L., Hartl, D., Chemisky, Y., Machado, L., & Popov, P. (2012). Constitutive model for the numerical analysis of phase transformation in polycrstalline shape memory alloys. International Journal of Plasticity,32–33, 155–183.

    Article  Google Scholar 

  10. 10.

    Rodrigue, H., et al. (2014). Cross-shaped twisting structure using SMA-based smart soft composite. International Journal of Precision Engineering and Manufacturing-Green Technology,1, 153–156.

    Article  Google Scholar 

  11. 11.

    Kim, H. I., Han, M. W., Song, S. H., & Ahn, S. H. (2016). Soft morphing hand driven by SMA tendon wire. Composites Part B Engineering,105, 138–148.

    Article  Google Scholar 

  12. 12.

    Rodrigue, H., Wang, W., Bhandari, B., Han, M. W., & Ahn, S. H. (2015). SMA-based smart soft composite structure capable of multiple modes of actuation. Composites Part B Engineering,82, 152–158.

    Article  Google Scholar 

  13. 13.

    Wang, W., Rodrigue, H., et al. (2016). Soft composite hinge actuator and application to compliant robot gripper. Composites Part B Engineering,98, 397–405.

    Article  Google Scholar 

  14. 14.

    Song, S. H., Lee, H., Lee, J. G., Lee, J. Y., Cho, M., & Ahn, S. H. (2016). Design and analysis of a smart soft composite structure for various modes of actuation. Composites Part B Engineering,95, 155–165.

    Article  Google Scholar 

  15. 15.

    Tanaka, K., Kobayashi, S., & Sato, Y. (1986). Thermomechanics of transformation pseudoelasticity and shape memory effect in alloys. International Journal of Plasticity,2, 59–72.

    Article  Google Scholar 

  16. 16.

    Porter, D. A., & Easterling, K. E. (1992). Phase transformations in metals and alloys, 2 edn, pp. 1–57.

  17. 17.

    Mincheol Kim, Yong-Jun Shin, Jang-Yeob Lee, Won-Shik Chu, Sung-Hoon Ahn, (2017) Pulse width modulation as energy-saving strategy of shape memory alloy based smart soft composite actuator. International Journal of Precision Engineering and Manufacturing 18(6):895–901

    Article  Google Scholar 

  18. 18.

    Kamita, T., & Matsuzaki, Y. (1998). One-dimensional pseudoelastic theory of shape memory alloys. Smart Materials and Structures,7, 489–495.

    Article  Google Scholar 

  19. 19.

    DYNALLOY. Inc. (2018). Flexinol actuator wire technical and design data. Technical Info.

Download references


This research was supported by a grant to Bio-Mimetic Robot Research Center Funded by Defense Acquisition Program Administration, and by Agency for Defense Development (UD190018ID), the National Research Foundation of Korea (NRF) funded by the MSIT (NRF-2018R1A2A1A13078704), the Basic Research Lab Program through the National Research Foundation of Korea (NRF) funded by the MSIT (2018R1A4A1059976), and Institute of Engineering Research, Seoul National University.

Author information



Corresponding author

Correspondence to Sung-Hoon Ahn.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Park, HB., Kim, DR., Kim, HJ. et al. Design and Analysis of Artificial Muscle Robotic Elbow Joint Using Shape Memory Alloy Actuator. Int. J. Precis. Eng. Manuf. 21, 249–256 (2020).

Download citation


  • Shape memory alloy
  • Tendon-driven
  • Robotic elbow joint