Highly-Sensitive Textile Pressure Sensors Enabled by Suspended-Type All Carbon Nanotube Fiber Transistor Architecture

Abstract

Among various wearable health-monitoring electronics, electronic textiles (e-textiles) have been considered as an appropriate alternative for a convenient self-diagnosis approach. However, for the realization of the wearable e-textiles capable of detecting subtle human physiological signals, the low-sensing performances still remain as a challenge. In this study, a fiber transistor-type ultra-sensitive pressure sensor (FTPS) with a new architecture that is thread-like suspended dry-spun carbon nanotube (CNT) fiber source (S)/drain (D) electrodes is proposed as the first proof of concept for the detection of very low-pressure stimuli. As a result, the pressure sensor shows an ultra-high sensitivity of ~3050 Pa−1 and a response/recovery time of 258/114 ms in the very low-pressure range of <300 Pa as the fiber transistor was operated in the linear region (VDS = −0.1 V). Also, it was observed that the pressure-sensing characteristics are highly dependent on the contact pressure between the top CNT fiber S/D electrodes and the single-walled carbon nanotubes (SWCNTs) channel layer due to the air-gap made by the suspended S/D electrode fibers on the channel layers of fiber transistors. Furthermore, due to their remarkable sensitivity in the low-pressure range, an acoustic wave that has a very tiny pressure could be detected using the FTPS.

Thin-film electronics on active substrates: review of materials, technologies and applications

“…Thin-film structures were also fabricated on cylindrical substrates such as metal wires [47,142,215], glass fibers [216], and optical fibers [217][218][219]. These devices were mainly utilised to create transistors for electronic textile applications [142,215,[217][218][219]. The high conformability of wires enables them to be used as substrates in smart textile applications.…”

3D Waterproof MXene‐Based Textile Electronics for Physiology and Motion Signals Monitoring

“…Among these physiological parameters, pulse, respiration, and body movement signals, which are related to external pressure, could all be captured by our textile sensors. So far, there have been several types of pressure sensors that are widely used, such as piezoelectric, [ 32,33 ] capacitive, [ 34–36 ] piezoresistive, [ 37–39 ] and triboelectric sensors, [ 40–42 ] among which the piezoresistive pressure sensors with high sensitivity, low detection limit, and excellent frequency response have been regarded as promising candidates in the field of wearable electronics.…”

Mechanically Robust, Antifatigue, and Temperature-Tolerant Nanocomposite Ionogels Enabled by Hydrogen Bonding as Wearable Sensors

“…Wearable electronics are attracting broad interest owing to their potential applications in human–machine communication, − health monitoring, − self-diagnosis, − and electronic skins. − Many emerging electronic devices, including metal- or semiconductor-based conductors, have been developed as artificial wearable sensors. − The focus of the sensors lies on the rational fabrication of conductive materials, which is expected to show a stable and reliable electrical signal upon the external pressure or deformation. It should be noted that the electronic conductors are intrinsically not stretchable, which restricts their complete fulfillment of the sensing demand in practice as the human body would move in various forms, including bending, twisting, and folding.…”