Author:
Zhang Qingqing,Xue Yuxuan,Zhao Yafei,Zou Kehan,Yuan Wenbo,Tian Yuqing,Chen Jiaming,Chen Jiangcheng,Xi Ning
Abstract
AbstractA rotary motor combined with fibrous string demonstrates excellent performance because it is powerful, lightweight, and prone to large strokes; however, the stiffness range and force-generating capability of twisted string transmission systems are limited. Here, we present a variable stiffness artificial muscle generated by impregnating shear stiffening gels (STGs) into a twisted string actuator (TSA). A high twisting speed produces a large impact force and causes shear stiffening of the STG, thereby improving the elasticity, stiffness, force capacity, and response time of the TSA. We show that at a twisting speed of 4186 rpm, the elasticity of an STG-TSA reached 30.92 N/mm, whereas at a low twisting speed of 200 rpm, it was only 10.51 N/mm. In addition, the STG-TSA exhibited a more prominent shear stiffening effect under a high stiffness load. Our work provides a promising approach for artificial muscles to coactivate with human muscles to effectively compensate for motion.
Funder
Research Grants Council of the Hong Kong Special Administrative Region
Basic Research Program of Shenzhen
National Natural Science Foundation of China
Innovation and Technology Fund
Publisher
Springer Science and Business Media LLC
Reference35 articles.
1. Ham, R. V. et al. Compliant actuator designs. IEEE Robot Autom. Mag. 16, 81–94 (2009).
2. Yang, Y., Chen, Y., Li, Y., Wang, Z. & Li, Y. Novel variable-stiffness robotic fingers with built-in position feedback. Soft Robot. 4, 338–352 (2017).
3. Ebrahimi, A., Gröninger, D., Singer, R. & Schneider, U. Control parameter optimization of the actively powered upper body exoskeleton using subjective feedbacks. ICCAR 2, 432–437 (2017).
4. Yang, Y., Chen, Y., Wei, Y. & Li, Y. Novel design and three-dimensional printing of variable stiffness robotic grippers. J. Mech. Robot. 8, 061010 (2016).
5. Li, Y. et al. Untethered multimode fluidic actuation: A new approach to soft and compliant robotics. Soft Robot. 8, 71–84 (2021).