Fiber-Based Sensors and Energy Systems for Wearable Electronics

Abstract

Wearable electronics have been receiving increasing attention for the past few decades. Particularly, fiber-based electronics are considered to be ideal for many applications for their flexibility, lightweight, breathability, and comfortability. Furthermore, fibers and fiber-based textiles can be 3D-molded with ease and potentially integrated with everyday clothes or accessories. These properties are especially desired in the fields of bio-related sensors and energy-storage systems. Wearable sensors utilize a tight interface with human skin and clothes for continuous environmental scanning and non-invasive health monitoring. At the same time, their flexible and lightweight properties allow more convenient and user-friendly experiences to the wearers. Similarly, for the wearable devices to be more accessible, it is crucial to incorporate energy harvesting and storage systems into the device themselves, removing the need to attach an external power source. This review summarizes the recent applications of fibers and fiber-based textiles in mechanical, photonic, and biomedical sensors. Pressure and strain sensors and their implementation as electronic skins will be explored, along with other various fiber sensors capable of imaging objects or monitoring safety and health markers. In addition, we attempt to elucidate recent studies in energy-storing fibers and their implication in self-powered and fully wireless wearable devices.

Functional Fiber Materials to Smart Fiber Devices

“…69 Due to the advantages of easy availability, biofriendliness, and renewability, many natural fiber-based devices have been developed. 19,70,71 For example, the natural fiber can be welded electrode yarns for knittable textile supercapacitors. 72,73 The surface roughness of the natural fiber materials can offer them high surface areas, thus allowing for high loading densities of active materials.…”

Recent Advances in Fiber-Shaped Electronic Devices for Wearable Applications

“…Wearable 1D sensors have been developed to accurately monitor the environment and health, which can be characterized using various optical, mechanical, and chemical signals [1]. The flexible and compact sensor devices can conform to dynamic and irregularly shaped surfaces to collect high-quality data.…”

“…In practical applications, fiber-shaped devices have attracted great attention as a potential alternative to conventional planar-type electronic devices. Because of their structural features, which enable them to be sewn into various fabrics, electronic fibers are an ideal device platform for realizing the three-dimensional (3D) deformability, light weight, breathability, washability, and comfort required for e-textiles [1][2][3]. Their one-dimensional (1D) shape allows fiber devices to maintain their electronic functions under various kinds of mechanical deformation and stimuli.…”

“…Recently, fiber electronics have advanced rapidly with the development of flexible electronics, stimuli-responsive sensors, and soft electronic materials. Unlike conventional electronic devices, electronic fibers require diverse fabrication methods, such as fused printing, spinning, electrodeposition, chemical vapor deposition, casting, rolling, molding, and thermal drawing [1,[6][7][8][9][10][11][12][13]. These scalable fabrication processes have themselves been developed to achieve more precise patterning and uniform deposition of the active materials.…”

New Progress on Fiber-Based Thermoelectric Materials: Performance, Device Structures and Applications

“…The temperature sensor is an important device applied to industrial production, medical diagnosis, and military defense and provides essential information about the dynamics of many physical, chemical, and biological phenomena [ 112 , 113 , 114 ]. To further meet the flexibility requirements, fiber-based temperature sensors are fabricated to be woven into fabrics or applied to curved surfaces [ 113 ].…”