Stretchable Polyurethane-Based Conductive Ink for E-Textile Applications
Authors: Pengxiang Si, Li Chen, Boxin Zhao, Alex Chen, John Persic and Robert Lyn Company: University of Waterloo, Celestica Inc., Microbonds Inc. Date Published: 1/30/2019
Abstract: E-textiles play an important role in wearable electronics such as sensor, supercapacitor and nanogenerator applications. Coating or printing conductive ink on textiles is a simple, inexpensive and large-scale manufacturing method. However, to obtain highly conductive conductors, most conductive inks that are metal-based and carbon-based suffer from their poor adhesion to the textile; the cured inks are prone to be wiped off and washed away. Some inks on textiles crack because of the rigid property of their binder and the porous and deformable structure of the textile. In addition, organic solvents are often used in conductive inks which are harmful to the environment and human body. In this paper, a new aqueous-based conductive ink, which can penetrate into the textile effectively and obtain high conductivity, high stretchability and high durability is described and analyzed. This ink uses a highly stretchable waterbased polyurethane as a binder. It is demonstrated that a textile coated with this ink can maintain high conductivity after 10 stretch cycles and 20 wash cycles. A strain E-textile sensor on the human body shows the potential application for tracking movement.