Design and fabrication of screen-printed silver circuits for stretchable electronics

Abstract

Stretchable electronics systems require stretchable circuits to electrically connect active and passive components on elastomeric substrates. As a new approach for low-cost stretchable interconnects, the extensibility of conductive circuits constructed by screen printing was investigated with four kinds of circuit designs: (single line, rectangular pulse, horseshoe and zigzag). All circuits were screen-printed on a thermoplastic polyurethane substrate using silver (Ag) nanopaste. They were then sintered at 150°C in air for various lengths of time (15, 30, 45, 60min). The fatigue resistance of circuits was assessed by a monotonic tensile test. While the Ag circuits were being elongated, their electrical resistances were measured in situ. The different circuit geometries and sintering times affected the extensibility of the Ag circuits, and the extensibility increased in the order of single line<zigzag<rectangular pulse<horseshoe. The extensibility also increased as the circuits were sintered for longer periods of time.