High-Power Hydro-Actuators Fabricated from Biomimetic Carbon Nanotube Coiled Yarns with Fast Electrothermal Recovery

• DOI: 10.1021/acs.nanolett.2c00250
• Publication Date: 2022-03-07T13:31:05Z
• Authors: Wonkyeong Son; Jae Myeong Lee; Shi Hyeong Kim; Hyeon Woo Kim; Sung Beom Cho; Dongseok Suh; Sungwoo Chun; Changsoon Choi
• Keywords: Power density

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 storing pre-twist into sheets subsequent electrochemical oxidation (ECO) treatment. resulting demonstrated structural stability even when one end cut off without possible loss pre-stored twists. HCNT provided maximal contractile work 863 J/kg at 11.8 MPa stress driven water. Moreover, time electrically heated yarns a direct current voltage 5 V 95% shorter than that neat electric heating. Finally, electrothermally showed high actuation frequency (0.17 Hz) density (143.8 W/kg).