Electrically Conducting Yarns for Electronic Textiles

Licentiate thesis, 2021

Electronic textiles (e-textiles) present a huge opportunity to incorporate wearable devices into textiles. Electrically conducting yarns and fibers can be utilized to create these e-textiles. For e-textiles to be wearable the development of electrically conducting yarns needs to rely on materials that are neither scares nor toxic. Certain functionalities are required for the conducing yarns which depends on the e-textile application. We have therefore explored different conducting materials, substrates, and various e-textiles devices to investigate vital conducting yarn properties. This thesis discusses the different conducting yarns and what textile processes have been used to make textile thermoelectric devices, organic electrochemical transistors, and Joule heating elements. Specifically, our PEDOT:PSS coated cellulose yarn that displays a, for cellulose, record-high bulk conductivity 36 Scm-1 is presented. The characterization of electrical and mechanical properties for yarns are also explored in this thesis. The durability of the PEDOT:PSS coated yarn was illustrated by showing that the yarn could be machine washed at least five times without conductivity loss. And the resilience was further exemplified by using a household sewing machine to make an out-of-plane thermoelectric textile device.