Silver Nanowire Coatings for Electrically Conductive Textiles

Abstract

There has been steep growth in wearable devices over the past 5 years and the ability to seamlessly integrate these devices into textiles is an exciting next step. One crucial component of achieving e-textiles is the ability of a textile to be electrically conductive for signal and power transfer. Commercially available conductive fabric typically involves metal plating, which degrades with bending and stretching. Recent alternative coatings such as polymers and carbon nanotubes have issues with low lifetimes and poor conductivity, respectively. These problems are addressed by coating fabrics and threads with networks of solution-processed silver nanowires. These silver nanowire coatings are conductive and mechanically flexible. Several deposition techniques were explored to coat fabrics including dip coating, brush coating, and transfer printing. In the latter, nanowires are printed on commercially available transfer paper coated using the Mayer rod coating technique and transferred onto different fabrics (cotton, polyester-cotton and viscose-linen). Transfer printing uses the least amount of silver nanowires compared to other coating techniques and is therefore lowest in cost. Sheet resistances in the range of 10 - 80 ohms/square with a materials cost estimate of $ 16 - 4/m^2 respectively were achieved using the transfer printing technique.