Biomechanical energy harvest based on textiles used in self-powering clothing

Abstract

Advanced triboelectric nanogenerator techniques provide a massive opportunity for the development of new generation wearable electronics, which toward multi-function and self-powering. Textiles have been refreshed with the requirement of flexible electronics in recent decades. In particular, knitted-textiles have exhibited enormous and prominent potential possibilities for smart wearable devices, which are based on the merits of high stretchability, excellent elasticity, comfortability as well as compatibility. Combined knitted textiles with nanogenerator techniques will promote the knitted textile triboelectric nanogenerators (KNGs) emerging, endowing conventional textiles with biomechanical energy harvesting and sensing energy supplied abilities. However, the design of KNGs and the construction of KNGs are based on features of human motions symbolizing considerable challenges in both high efficiency and excellent comfort. Currently, this review is concerned with KNGs construction account of triboelectric effects referring to knitted-textile classifications, structural features, human motion energy traits, working mechanisms, and practical applications. Moreover, the remaining challenges of industrial production and the future prospects of knitted-textile triboelectric nanogenerators of harvesting biomechanical energy are presented.

Fibrous triboelectric nanogenerators: fabrication, integration, and application

“…Weaving is a textile processing technology to form fabrics by intersecting two sets of yarns known as warp yarns (lengthwise) and we yarns (widthwise) at a right angle, which can be fabricated by hand-weaving or using a weaving machine. 51,56 In smart textiles woven using continuous F-TENGs, the formed interlacing provides friction between the we and warp yarns, and thus the weaving patterns of the textile have a great impact on its electrical output. 6,68 By changing the position and number of we and warp yarns, the woven textiles can achieve a variety of structural designs, including basic structures (plain, twill, and satin) and derivative structures (honeycomb, rib weave, etc.)…”

“…Knitting is a process to manufacture fabrics by intermeshing loops of yarns following a meandering path, which can be achieved using a at knitting machine. 51,127,140 During the knitting technique, a large area of fabric can be fabricated using single yarn, and thus the T-TENGs fabricated by knitting do not need complicated wiring. 141 In addition, knitted fabrics present the ability to be easily deformed due to their structure in which the meandering and suspended loops of yarns are continuously arranged, and thus knitting is a suitable technique to produce E-textiles with outstanding stretchability (Fig.…”

“…28,37,49,50 F-TENGs with different working modes show distinct structural features and superiorities, which are adapted to different wearable conditions. 26,51 Both the SE mode and CS mode are suitable for generating electric power under periodic actions including pressure, shock, and vibration, and thus F-TENGs are suitable for application under conditions of frequent external forces, such as in insoles and carpets. 52,53 Comparatively, F-TENGs with the SE mode are easier to fabricate, whereas the fabrication of F-TENGs with the CS mode is complex, greatly hindering their industrial mass production and integration with the commercial fabric.…”

“…54 The LS and FS working modes can also be realized by integrating multiple F-TENGs into a T-TENG with a specific structure, which are suitable to harvest energy from planar motions or rotation. 51,54,55 T-TENGs with the LS mode and FS mode can be considered for placement under the armpits or at the elbows of clothes to obtain energy by swinging the arm.…”

Analyzing the output performance of the knitted triboelectric nanogenerator based on the fish-scale shape using fast Fourier transform

“…In 2012, Wang 14 investigated the triboelectric nanogenerator (TENG), which has low weight, simple preparation, high efficiency, and a great mechanical-to-electric conversion capability for applications in personal health and human motion detection. [15][16][17] TENGs based on membranes [18][19][20] and textiles [21][22][23][24] have made excellent progress in enriching a wide range of intelligent wearables. Textiles, which combine the benefits of breathability, compatibility, washability, light weight, low price, and integration with a garment, exhibit great application prospects in the TENG.…”