Abstract
Bioinspired yarn/fiber structured hydro-actuators have recently attracted significant attention. However, most water-driven mechanical actuators are unsatisfactory because of the slow recovery process and low full-time power density. A rapidly recoverable high-power hydro-actuator is reported by designing biomimetic carbon nanotube (CNT) yarns. The hydrophilic CNT (HCNT) coiled yarn was prepared by storing pre-twist into CNT sheets and subsequent electrochemical oxidation (ECO) treatment. The resulting yarn demonstrated structural stability even when one end was cut off without the possible loss of pre-stored twists. The HCNT coiled yarn actuators provided maximal contractile work of 863 J/kg at 11.8 MPa stress when driven by water. Moreover, the recovery time of electrically heated yarns at a direct current voltage of 5 V was 95% shorter than that of neat yarns without electric heating. Finally, the electrothermally recoverable hydro-actuators showed a high actuation frequency (0.17 Hz) and full-time power density (143.8 W/kg).
Original language | English |
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Pages (from-to) | 2470-2478 |
Number of pages | 9 |
Journal | Nano Letters |
Volume | 22 |
Issue number | 6 |
DOIs | |
State | Published - 23 Mar 2022 |
Bibliographical note
Funding Information:This work was supported by the Korea Institute of Industrial Technology (KITECH EH220002) and the Basic Science Research Programs through the National Research Foundation of Korea (NRF-2017R1A6A3A04004987 and NRF-2021R1A2C2005281).
Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
Keywords
- biomimetics
- carbon nanotube yarn
- electrothermal recovery
- hydro-actuator
- power density