Improving durability and electrical performance of flexible printed e-textile conductors via domestic ironing

Abstract

The electrical performance of printed conductors often degrades over time due to recurrent or infrequent exposure to practical stresses such as bending and washing. To avoid this, a repair mechanism is required to return the conductor to prime condition, enhancing lifetime and durability during extended stress cycles. In this study, domestic ironing is used to repair and restore the electrical resistance of printed conductors damaged by prolonged bending and washing cycles at standard ironing temperatures. The results of reliability tests on screen-printed conductors on two polyurethane-coated fabrics and six different laminate sheets adhered to the fabrics revealed that ironing significantly enhances the electrical performance of the conductors, limiting the change in electrical resistance to less than 20% after 400 000 bending cycles and to less than 1 Ω after 50 wash cycles. Although laminated conductors are more durable and generally outperformed conductors on the printed primer layer, in both cases, the results showed that the sample could be left for 24 h for ‘self-relaxation’ and would also return to the original value, implying that for future wear, either immediate ironing or leaving the garment for a period between uses could effectively ‘fix’ any bending or washing damage.