Fast, variable stiffness-induced braided coiled artificial muscles
Biomimetic actuation technologies with high muscle strokes, cycle rates, and work capacities are necessary for robotic systems. We present a muscle type that operates based on changes in muscle stiffness caused by volume expansion. This muscle is created by coiling a mechanically strong braid, in which an elastomer hollow tube is adhesively attached inside. We show that the muscle reversibly contracts by 47.3% when driven by an oscillating input air pressure of 120 kilopascals at 10 Hz. It generates a maximum power density of 3.0 W/g and demonstrates a mechanical contractile efficiency of 74%. The muscle's low-pressure operation allowed for portable, thermal pneumatical actuation. Moreover, the muscle demonstrated bipolar actuation, wherein internal pressure leads to muscle length expansion if the initial muscle length is compressed and contraction if the muscle is not compressed. Modeling indicates that muscle expansion significantly alters its stiffness, which causes muscle actuation. We demonstrate the utility of BCMs for fast running and climbing robots.
Authors
- Jianning Ding (ORCID: https://orcid.org/0000-0003-3606-9627)
- Ray H. Baughman (ORCID: https://orcid.org/0000-0001-5845-5137)
- Xinghao Hu (ORCID: https://orcid.org/0000-0002-7057-884X)
- Shaoli Fang (ORCID: https://orcid.org/0009-0008-2669-9581)
- Guanggui Cheng (ORCID: https://orcid.org/0000-0001-7327-4836)
- Xiangyu Wang (ORCID: https://orcid.org/0009-0004-4746-3317)
- Jian Wang (ORCID: https://orcid.org/0000-0001-5130-300X)
- Guorong Zhang (ORCID: https://orcid.org/0000-0001-8661-5230)
- Fengrui Zhang (ORCID: https://orcid.org/0000-0002-9073-8548)
- Ye Xiao (ORCID: https://orcid.org/0000-0002-2711-7722)
Institutions
- Jiangsu University (CN)
- The University of Texas at Dallas (US)
- Northwestern Polytechnical University (CN)
- Yangzhou University (CN)
Publication Details
- Journal
- Proceedings of the National Academy of Sciences
- Published
- 2024-09-30
- DOI
- https://doi.org/10.1073/pnas.2412288121
- Citations
- 11
- Primary Topic
- Advanced Sensor and Energy Harvesting Materials
- Type
- article
- Field-Weighted Citation Impact
- 2.03
Funders
- Welch Foundation
- National Natural Science Foundation of China
- China Postdoctoral Science Foundation
- Government of Jiangsu Province
- Natural Science Foundation of Jiangsu Province
- Postdoctoral Research Foundation of China
- Air Force Office of Scientific Research