One-step metallization of weft-knitted fabrics for wearable biaxial strain sensors

• Published in: Scientific reports Vol. 12; no. 1; pp. 20029 - 9
• Main Authors: Tai, Chao-Yi, Lin, Chun-Yu, Liu, Tang-Chun, Jia, Lu-Chiang, Jones, Thomas, Abdolvand, Amin
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 21.11.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1005/1009; 639/301/930/1032; 639/624/1075/1080; Anisotropy; Coffee; Crystallization; Electric Conductivity; Fabrics; Humanities and Social Sciences; Irradiation; Lasers; multidisciplinary; Photonics; Photoreduction; Polyesters - chemistry; Polyethylene terephthalate; Polyurethanes - chemistry; Science; Science (multidisciplinary); Sensors; Silver; Sintering; Spectrum analysis; Surface tension; Textiles; Viscosity; Wearable Electronic Devices; Yarn
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-24676-7

One-step direct patterning of high definition conductive tracks in textiles is realized through laser direct writing in combination with a silver organometallic ink developed in-house. Photoreduction, nano-crystallization, and sintering are accomplished in one pass under the irradiation of a CW green laser light (λ = 532 nm) at moderate intensities (I ≥ 95 mW/mm 2 ). By tailoring the surface tension and viscosity of the ink, high-definition conductive tracks are formed in weft-knitted polyester-Spandex composite fabrics, well-following the laser’s profile with negligible coffee stain effect. Length resistance as low as 4 Ω/cm is measured and anisotropy of the gauge factor as high as 25 is achieved. The metallized fabric exhibits reversible and hysteresis-free electromechanical responses subject to high strains. Durability assessment qualifies that the as-metallized strain sensors are able to sustain their performance for over 5000 stretch/release cycles, demonstrating its potential applications in biaxial strain sensing and interactive smart textiles.