1
|
Wang Y, Wang X, Zhao Y, Dong L, Zhou T, Yong Z, Di J. Reversible Electrochemical Swelling of Straight Carbon Nanotube Yarns for High-Performance Linear Actuation. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2405277. [PMID: 39189539 DOI: 10.1002/smll.202405277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 08/14/2024] [Indexed: 08/28/2024]
Abstract
Coiled artificial muscle yarns outperform their straight counterparts in contractile strokes. However, challenges persist in the fabrication complexity and the susceptibility of the coiled yarns to becoming stuck by surrounding objects during contraction and recovery. Additionally, torsional stability remains a concern. In this study, it is reported that straight carbon nanotube (CNT) yarns when driven by a low-voltage electrochemical approach, can achieve a contractile stroke that surpasses even NiTi shape memory alloy fibers. The key lies in the suitable match between a yarn consisting of randomly aligned CNTs and the reversible and substantial electrochemical swelling induced by solvated ions. Wrinkled structures are formed on the surface of the CNT yarn to adapt to the swelling process. This not only assures torsional stability but also enhances the surface area for improved electrode-electrolyte interaction during electrochemical actuation. Remarkably, the CNT artificial muscle yarn generates a contractile stroke of 8.8% and an isometric stress of 7.5 MPa under 2.5 V actuation voltages, demonstrating its potential for applications requiring low energy consumption while maintaining high operational efficiency. This study highlights the crucial impact of CNT orientation on the effectiveness of electrochemically-driven artificial muscles, signaling new possibilities in smart material and biomechanical system development.
Collapse
Affiliation(s)
- Yulian Wang
- Advanced Materials Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
- State Key Laboratory of Pharmaceutical Biotechnology, Division of Sports Medicine and Adult Reconstructive Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China
| | - Xiaobo Wang
- Advanced Materials Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
| | - Yueran Zhao
- Advanced Materials Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
| | - Lizhong Dong
- Advanced Materials Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
| | - Tao Zhou
- Division of Nanomaterials and Jiangxi Key Lab of Carbonene Materials, Jiangxi Institute of Nanotechnology, Nanchang, 330200, China
| | - Zhenzhong Yong
- Advanced Materials Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
- Division of Nanomaterials and Jiangxi Key Lab of Carbonene Materials, Jiangxi Institute of Nanotechnology, Nanchang, 330200, China
| | - Jiangtao Di
- Advanced Materials Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
- Division of Nanomaterials and Jiangxi Key Lab of Carbonene Materials, Jiangxi Institute of Nanotechnology, Nanchang, 330200, China
| |
Collapse
|
2
|
Constitutive Equations for Analyzing Stress Relaxation and Creep of Viscoelastic Materials Based on Standard Linear Solid Model Derived with Finite Loading Rate. Polymers (Basel) 2022; 14:polym14102124. [PMID: 35632006 PMCID: PMC9143375 DOI: 10.3390/polym14102124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 05/18/2022] [Accepted: 05/20/2022] [Indexed: 02/06/2023] Open
Abstract
The viscoelastic properties of materials such as polymers can be quantitatively evaluated by measuring and analyzing the viscoelastic behaviors such as stress relaxation and creep. The standard linear solid model is a classical and commonly used mathematical model for analyzing stress relaxation and creep behaviors. Traditionally, the constitutive equations for analyzing stress relaxation and creep behaviors based on the standard linear solid model are derived using the assumption that the loading is a step function, implying that the loading rate used in the loading process of stress relaxation and creep tests is infinite. Using such constitutive equations may cause significant errors in analyses since the loading rate must be finite (no matter how fast it is) in a real stress relaxation or creep experiment. The purpose of this paper is to introduce the constitutive equations for analyzing stress relaxation and creep behaviors based on the standard linear solid model derived with a finite loading rate. The finite element computational simulation results demonstrate that the constitutive equations derived with a finite loading rate can produce accurate results in the evaluation of all viscoelastic parameters regardless of the loading rate in most cases. It is recommended that the constitutive equations derived with a finite loading rate should replace the traditional ones derived with an infinite loading rate to analyze stress relaxation and creep behaviors for quantitatively evaluating the viscoelastic properties of materials.
Collapse
|
3
|
Chou CE, Liu YL, Zhang Y, Hsueh CH, Yang F, Lee S. Thermomechanical deformation of polyethylene-terephthalate artificial muscles. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.123013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
4
|
Sun J, Tighe B, Liu Y, Zhao J. Twisted-and-Coiled Actuators with Free Strokes Enable Soft Robots with Programmable Motions. Soft Robot 2020; 8:213-225. [PMID: 32584186 DOI: 10.1089/soro.2019.0175] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Various actuators (e.g., pneumatics, cables, dielectric elastomers, etc.) have been utilized to actuate soft robots. Besides widely used actuators, a relatively new artificial muscle-twisted-and-coiled actuators (TCAs)-is promising for actuating centimeter-scale soft robots because they are low cost, have a large work density, and can be driven by electricity. However, existing works on TCA-actuated soft robots in general can only generate simple bending motion. The reason is that TCAs fabricated with conventional methods have to be preloaded to generate a large contraction, and thus cannot actuate soft robots properly. In this work, an upgraded technique is presented to fabricate TCAs that can deliver 48% free strokes (contraction without preloading). We first compare the static performance of TCAs with free strokes with conventional TCAs, and then characterize how will the fabrication parameters influence the TCAs' stroke and force capability. After that, we demonstrate that such TCAs can actuate centimeter-scale soft robots with programmable motions (gripping, twisting, and three-dimensional bending). Finally, we combine those motions to demonstrate a soft robotic arm that can perform a pick-and-place task. We expect that TCAs with free strokes can enable miniature soft robots with rich three-dimensional motions for both locomotion and manipulation. Because TCAs are electrically driven, we can also potentially develop untethered soft robots by carrying onboard batteries and control circuits.
Collapse
Affiliation(s)
- Jiefeng Sun
- Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado, USA
| | - Brandon Tighe
- Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado, USA
| | - Yingxiang Liu
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, China
| | - Jianguo Zhao
- Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado, USA
| |
Collapse
|
5
|
|