Achieving Highly Conductive, Stretchable, and Washable Fabric from Reactive Silver Ink and Increased Interfacial Adhesion

Abstract

There is a major need to manufacture highly electrically conductive fabrics with stretch- and wash-durability. In this work, we provide both modeling and experiments of the mechanical failure of silver ink coatings on knitted fabric. Large thickness metal films are needed for high conductance but tend to debond from the underlying fabric microfibers that lead to cracking and failure. Strong adhesion between the metal film and microfiber is thus key to achieving high thickness films with good mechanical robustness. The use of a reactive silver ink addresses this need due to in situ silver reduction and conformal coverage. Furthermore, a chemical etchant pretreatment of the textile microfibers functionalizes the surface to enable covalent bonding with the surface and increases theinterface area. The use of a polymer provides for an additional protective barrier during washing. Treated fabrics demonstrate low sheet resistance <100 mΩ per square with only two coats and <200 mΩ per square after 1000 stretching cycles or 300 min of ultrasonic washing with detergent.