In Situ Formation of Ag Nanoparticles for Fiber Strain Sensors: Toward Textile-Based Wearable Applications

Abstract

Wearable electronic devices have attracted significant attention as important components in several applications. Among various wearable electronic devices, interest in textile electronic devices is increasing because of their high deformability and portability in daily life. To develop textile electronic devices, fiber-based electronic devices should be fundamentally studied. Here, we report a stretchable and sensitive fiber strain sensor fabricated using only harmless materials during an in situ formation process. Despite using a mild and harmless reducing agent instead of typical strong and hazardous reducing agents, the developed fiber strain sensors feature a low initial electrical resistance of 0.9 Ω/cm, a wide strain sensing range (220%), high sensitivity (∼5.8 × 10 4 ), negligible hysteresis, and high stability against repeated stretching−releasing deformation (5000 cycles). By applying the fiber sensors to various textiles, we demonstrate that the smart textile system can monitor various gestures in real-time and help users maintain accurate posture during exercise. These results will provide meaningful insights into the development of next-generation wearable applications.

Crack-Based Core-Sheath Fiber Strain Sensors with an Ultralow Detection Limit and an Ultrawide Working Range

“…With the fast growth of wearable sensing devices, flexible strain sensors have received considerable interest and have shown substantive applications in various fields, such as human motion monitoring, − artificial intelligence robot, , and human–machine interaction. − As a vital component of strain sensors, resistive strain sensors have attracted extensive research interest because of their easy fabrication, fast response mechanism, and simple read-out systems. , From the perspective of human motion monitoring, to monitor both tiny changes (e.g., pulse and swallowing) and large strain changes (e.g., finger and joint movement) in the body, sensitivity and sensing range are two important parameters to be considered in the design of flexible resistive strain sensors. , However, there is always a trade-off between sensitivity and sensing range . High sensitivity stems from considerable structural change under a tiny change in strain.…”

“…6−8 As a vital component of strain sensors, resistive strain sensors have attracted extensive research interest because of their easy fabrication, fast response mechanism, and simple read-out systems. 9,10 From the perspective of human motion monitoring, to monitor both tiny changes (e.g., pulse and swallowing) and large strain changes (e.g., finger and joint movement) in the body, sensitivity and sensing range are two important parameters to be considered in the design of flexible resistive strain sensors. 11,12 However, there is always a trade-off between sensitivity and sensing range.…”

Mechanically robust textile-based strain and pressure multimodal sensors using metal nanowire/polymer conducting fibers

“…In particular, the textile-based wearable electronics hold a great promise owing to their unique physical characteristics such as compatibility with common clothing, light weight, softness, and inherent snug properties ( Keum et al., 2021a ). For these reasons, various sensor devices have been demonstrated on textile platform including pressure ( Pyo et al., 2019 ; Lee et al., 2015 ), strain ( Kim et al., 2021 ; Eom et al., 2017b ), temperature ( Wu et al., 2019 ), and humidity sensors ( Zhou et al., 2017 ; Ma et al., 2019 ). More recently, in addition to these single-mode type sensor devices, multimodal textile sensors capable of detecting multiple stimuli were demonstrated ( Wu et al., 2019 ; Chen et al., 2021 ).…”

In Situ Growth of Nanosilver on Fabric for Flexible Stretchable Electrodes

“…Montes [ 32 ] et al solved the problem of weak adsorption of Ag nanoparticles on the surface of composite fabric by in situ growth of Ag nanoparticles on different types of textile fibers so that Ag nanoparticles uniformly covered the surface and interior of the fabric. Kim et al [ 33 ] prepared a stretchable fiber strain sensor based on an in situ growth process by using mild and harmless sodium ascorbate as a reducing agent, with a low square resistance of 0.9 Ω/cm and high stability over repeated tensile release cycles (5000 cycles). Although the above conductive fabric prepared by in situ growth further strengthens the bond between the nanosilver and the fabric, the nanosilver particles on the surface of the fibers are scattered in various places and do not form a connection with each other.…”