Simulation based optimization of textile integrated circuits and conductors

Abstract

Textiles with integrated electronic functions (e-textiles) offer comfortable and unobtrusive solutions for the measurement and monitoring of body functions in sports, medical or therapeutic garments. Weft knitted stretchable textiles can ensure close skin contact and freedom of movement, but pose a challenge for the integration of electronics because mechanical stability and robustness of the conductors have to be ensured for reliable e-textile systems. Different properties of substrate material and integrated conductors can result in locally inhomogeneous deformations. Simulation-based optimization of weft knitted structures on a stitch level with the ability to predict mechanical properties has potential to ensure the robustness of knitted e-textiles without the need for time and resource intensive experiments. To verify the approach, simulated properties obtained with the software TexMath were compared with mechanical testing of knitted samples. By comparing different knit structures, the simulation could show that changing knit stitch or yarn thickness, the strain on integrated conductors can be lowered considerably, to around half the initial value. Similarly, localized doubling of yarn is shown to increase stability around stiff components of the e-textile system. The results show the excellent capability of TexMath in assessing textile properties in weft-knitted e-textile and its applicability for optimization of textile properties and reduction of structural defects under tensile loading.