Toward Fully Manufacturable, Fiber Assembly–Based Concurrent Multimodal and Multifunctional Sensors for e‐Textiles

Abstract

challenge, however, is to engender electrical functionalities in textiles while preserving the desirable textile qualities such as softness, comfort, flexibility, and texture that arise from its hierarchical structure through the complex interaction of inherent fiber material properties and the characteristic textile structural features at multiple length scales. To this end, among all the different potential routes of incorporating electronic functionalities into textiles, integration of textile fibers performing as electrical devices, on its own or when assembled, seems to provide the most obvious, unobtrusive, and practical means. Appropriately designed flexible fiber-based electronics are fundamentally transformational; they present very attractive possibilities of ease of manufacturing using standard fiber-extrusion, roll-to-roll textile processing technologies, and enable high spatial sensing density with redundancy within the textile structure. The utility of fiber-based electronics has been recognized as a key step for truly mass-produced e-textiles. Accordingly, the constituents (e.g., fibers or yarns) of textile products have been directly fashioned into electrical devices by incorporating appropriate functional design and materials. These include "fiber"shaped photovoltaic devices, [1,2] transistors, [3][4][5] logic circuits, [6,7] sensors, [8,9] actuators, [10][11][12] other electronic/optical devices [13][14][15] in addition to "fabric"-based devices. [16,17] Modulation of resistance and/or capacitance have been the two most common strategies to sense various physical stimuli, such as applied forces [8,18] and moisture. [19,20] Piezoresistive sensors in the form of fibers/yarns and printed layers on fabrics have been proposed for monitoring motion, posture, and various physiological signals for patient monitoring and rehabilitation. [21,22] For pressure measurements, multicore fibers consisting of layers of soft dielectric and conductive polymers or thin metal films, [23,24] sets of orthogonal fibers, [25,26] or fabric-like structures with soft dielectric and conductive fibers [27] have been employed to form capacitive structures. While remarkable progress has been made in e-textiles, practical real-life products in e-textiles remain elusive. Arguably, the most difficult challenge has been the development of truly textile/fiber-compatible materials/devices and practical Soft polymer-based sensors as an integral part of textile structures have attracted considerable scientific and commercial interest recently because of their potential use in healthcare, security systems, and other areas. While electronic sensing functionalities can be incorporated into textiles at one or more of the hierarchical levels of molecules, fibers, yarns, or fabrics, arguably a more practical and inconspicuous means to introduce the desired electrical characteristics is at the fiber level, using processes that are compatible to textiles. Here, a prototype multimodal and multifunctional sensor array formed within a woven fabr...

Electrically Conductive Coatings for Fiber-Based E-Textiles

“…In terms of applications for fibers and yarns, CB is used more often as a conductive filler to spin or cast fibers using techniques such as melt spinning [91] or 3D printing [1]. Even so, in conjunction with other materials such as ICPs, CB has been used to apply conductive coatings onto yarns or fibers, such as the work done by Villanueva et al to coat cotton yarn with a CB/PPy dispersion via dip-coating [92].…”

“…In recent years, electronic textiles (e-textiles) as a class of soft or flexible electronics have generated a growing interest due to their many potential applications in healthcare, security, entertainment, and others. E-textile systems are produced through the integration of various electrical devices, such as sensors [1][2][3], transistors [4][5][6][7], communication devices [8][9][10], energy harvesting and storage devices [11][12][13][14], and actuators [15][16][17][18], with textiles. As a hierarchical structure, textiles offer unique opportunities to integrate electrical functionalities at various levels-from fibers, yarns, to the finished product [19] (see Figure 1).…”

“…Electrical conductivity at the fiber level can be achieved by using either intrinsically conducting polymers (ICPs) in forming the fiber or by coating conventional insulating fibers with conducting materials [21]. Various materials such as ICPs [22,23], conducting polymer composites [24,25], metals [21,26], and carbon based materials, such as carbon nanotubes [27,28], carbon nanopowders [1] and graphene [29,30], have been used to achieve this. These materials have been applied using coating methods such as electro-and electroless deposition [31][32][33], dip-coating [34,35], and chemical vapor deposition (CVD) [23,30] to achieve such electrically conductive e-textile coatings.…”

Textile Electronics for VR/AR Applications

“…developed a woven fabric made of bicomponent fiber, which can sense different forces, biopotential, and wetness. [ 77 ] The main issue of multi‐sensation is signal interference during the process of conducting a decoupling analysis. Apart from sensation, other additional functions, such as energy harvesting, are further preferred for integration in the sensor.…”

Thermal management of wearable and implantable electronic healthcare devices: Perspective and measurement approach

“…45 Meanwhile, a portable design is crucial for wearable devices, which consist of a few components and are medium in size. Examples of portable devices are wrist-mounted 46,47 and head-mounted 15,48 sensors, e-textiles, 49,50 and wearable artificial kidney (WAK). [51][52][53]…”