Incorporation of carbon nanotubes (CNTs) into textiles without sacrificing their intrinsic properties provides a promising platform in exploring wearable technology. However, manufacture of flexible, durable, and stretchable CNT/textile composites on an industrial scale is still a great challenge. We hereby report a facile way of incorporating CNTs into the traditional yarn manufacturing process by dipping and drying CNTs into cotton rovings followed by fabricating CNT/cotton/spandex composite yarn (CCSCY) in sirofil spinning. The existence of CNTs in CCSCY brings electrical conductivity to CCSCY while the mechanical properties and stretchability are preserved. We demonstrate that the CCSCY can be used as wearable strain sensors, exhibiting ultrahigh strain sensing range, excellent stability, and good washing durability. Furthermore, CCSCY can be used to accurately monitor the real-time human motions, such as leg bending, walking, finger bending, wrist activity, clenching fist, bending down, and pronouncing words. We also demonstrate that the CCSCY can be assembled into knitted fabrics as the conductors with electric heating performance. The reported manufacturing technology of CCSCY could lead to an industrial-scale development of e-textiles for wearable applications.
Conductive cotton fabric was prepared by coating single-wall carbon nanotubes (CNTs) on a knitted cotton fabric surface through a "dip-and-dry" method. The combination of CNTs and cotton fabric was analyzed using scanning electron microscopy (SEM) and Raman scattering spectroscopy. The CNTs coating improved the mechanical properties of the fabric and imparted conductivity to the fabric. The electromechanical performance of the CNT-cotton fabric (CCF) was evaluated. Strain sensors made from the CCF exhibited a large workable strain range (0~100%), fast response and great stability. Furthermore, CCF-based strain sensors was used to monitor the real-time human motions, such as standing, walking, running, squatting and bending of finger and elbow. The CCF also exhibited strong electric heating effect. The flexible strain sensors and electric heaters made from CCF have potential applications in wearable electronic devices and cold weather conditions.
Flexible wearable devices for various applications have attracted
research attention in recent years. To date, it is still a big challenge
to fabricate strain sensors with a large workable strain range while
maintaining their high sensitivity. Herein, we report the fabrication
of highly sensitive wearable strain sensors from braided composite
yarns (BYs) by in situ polymerization of polypyrrole (PPy) on the
surface of yarns after polydopamine templating (BYs–PDA). The
electromechanical performance and strain sensing properties of the
fabricated braided composite yarn@polydopamine@polypyrrole (BYs–PDA–PPy)
were investigated. Because of the unique braided structure of BYs,
the BYs–PDA–PPy strain sensors exhibit fascinating performance,
including a large workable strain range (up to 105% strain), high
sensitivity (gauge factor of 51.2 in strain of 0%–40% and of
27.6 in strain of 40%–105%), long-term stability and great
electrical heating performance. Furthermore, the BYs–PDA–PPy
sensors can be used in real-time monitoring subtle and large human
motions. The BYs–PDA-PPy strain sensors can also be woven into
fabrics for large area electric heating. These results demonstrate
the potential of BYs–PDA–PPy in wearable electronics.
Flexible electronic
devices with strain
sensing and energy storage functions integrated simultaneously are
urgently desirable to detect human motions for potential wearable
applications. This paper reports the fabrication of a cotton/carbon
nanotube sheath–core yarn deposited with polypyrrole (PPy)
for highly multifunctional stretchable wearable electronics. The microscopic
structure and morphology of the prepared sheath–core yarn were
characterized by scanning electron microscopy and Fourier transform
infrared spectrometry. A mechanical experiment demonstrated its excellent
stretchable capacity because of its unique spring-like structure.
We demonstrate that the sheath–core yarn can be used as wearable
strain sensors, exhibiting an ultrahigh strain sensing range (0–350%)
and excellent stability. The sheath–core yarn can be used in
highly sensitive real time monitoring toward both subtle and large
human motions under different conditions. Furthermore, the electrochemical
performance of the sheath–core yarn was characterized by cyclic
voltammetry, galvanostatic charge–discharge, and electrochemical
impedance spectroscopy. The measured areal capacitance was 761.2 mF/cm2 at the scanning rate of 1 mV/s. The method of spinning technology
may lead to new exploitation of CNTs and PPy in future wearable electronic
device applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.