Highly twisted supercoils for superelastic multi-functional fibres

• Published in: Nature communications Vol. 10; no. 1; p. 426
• Main Authors: Son, Wonkyeong, Chun, Sungwoo, Lee, Jae Myeong, Lee, Yourack, Park, Jeongmin, Suh, Dongseok, Lee, Duck Weon, Jung, Hachul, Kim, Young-Jin, Kim, Younghoon, Jeong, Soon Moon, Lim, Sang Kyoo, Choi, Changsoon
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 25.01.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 147/135; 639/4077/4079/4105; 639/925/357/73; Bias; Capacitance; Carbon; Carbon nanotubes; Coiling; Coils; Deformation; Deformation resistance; Elastic deformation; Fibers; Formability; Humanities and Social Sciences; Morphology; multidisciplinary; Muscles; Scanning electron microscopy; Science; Science (multidisciplinary); Sheaths; Supercoiling; Superelasticity
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-08016-w

Highly deformable and electrically conductive fibres with multiple functionalities may be useful for diverse applications. Here we report on a supercoil structure (i.e. coiling of a coil) of fibres fabricated by inserting a giant twist into spandex-core fibres wrapped in a carbon nanotube sheath. The resulting supercoiled fibres show a highly ordered and compact structure along the fibre direction, which can sustain up to 1,500% elastic deformation. The supercoiled fibre exhibits an increase in resistance of 4.2% for stretching of 1,000% when overcoated by a passivation layer. Moreover, by incorporating pseudocapacitive-active materials, we demonstrate the existence of superelastic supercapacitors with high linear and areal capacitance values of 21.7 mF cm -1 and 92.1 mF cm -2 , respectively, that can be reversibly stretched by 1,000% without significant capacitance loss. The supercoiled fibre can also function as an electrothermal artificial muscle, contracting 4.2% (percentage of loaded fibre length) when 0.45 V mm -1 is applied. The development of electrically conductive fibres is attractive for wearable electronics, but performance should be maintained upon deformation and tensile strain. Here the authors fabricate flexible, stretchable, carbon nanotube-coated spandex fibres for supercapacitors and artificial muscles.