Study On The Structure And Optical Properties Of Fiber Warp-knitted Fabrics Under Tension

With the progress of science and technology,people pay more and more attention to health problems,and the research of medical intelligent textiles is becoming more and more important.At present,in the field of medical textiles,many applications are electronic sensors due to their small size,lightweight and relatively high sensitivity.Normally,however,they can not work in the electromagnetic environment.Therefore,polymer optical fiber which possessing anti-electromagnetic features become more and more popular.In this study,warp knitted optical sensing fabrics were designed and made by using two full-threaded guide-bar warp knitted base structures and inlaying optical fibers.And the optical properties of resultant sensing fabrics under uniaxial stretching were evaluated.Firstly,the structural characteristics of warp knitted base fabrics were analyzed and their geometrical changes under uniaxial stretching were examined.Then optical fiber was inlayed into the warp knitted structures to form the sensing fabrics.Four two-guide-bar warp knitted structures were adopted.They are two bar tricot,locknit,reverse Iocknit,and modified Sharkskin(cord lap in back guide bar and satin lap in front guide bar).After that,optical fiber with diameter of 1000μm was inlayed into the base fabrics as a semi-circle shape with a radius of 10mm.At the same time,the sensing fabric was stretched along with one direction and the changes of the structure and optical signals during stretching were examined,the signal change of the optical fabric because of macro-bending and micro-bending was theoretical investigated and the factors which have influences on signal loss were analyzed.In addition,the attenuation coefficient and optical sensitivity of optical fibers embedded in base structures were tested.These may provide theoretical and experimental bases for developing warp knitted optical sensing products.