title: High-resolution, high-aspect ratio conductive wires embedded in plastic substrates.
abstract: A novel method is presented to fabricate high-resolution, high-aspect ratio metal wires embedded in a plastic substrate for flexible electronics applications. In a sequential process, high-resolution channels connected to low-resolution reservoirs are first created in a thermosetting polymer by imprint lithography. A reactive Ag ink is then inkjet-printed into the reservoirs and wicked into the channels by capillary forces. These features serve as a seed layer for copper deposition inside the channels via electroless plating. Highly conductive wires (>50% bulk metal) with minimum line width and spacing of 2 and 4 μm, respectively, and an aspect ratio of 0.6 are obtained. The embedded wires exhibit good mechanical flexibility, with minimal degradation in electrical performance after thousands of bending cycles.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota , 421 Washington Avenue S.E., Minneapolis, Minnesota 55455, United States.
authors.forename: Ankit
authors.initials: A
authors.lastname: Mahajan
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Hyun
authors.forename: S Brett
authors.initials: SB
authors.lastname: Walker
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Lewis
authors.forename: Lorraine F
authors.initials: LF
authors.lastname: Francis
authors.forename: C Daniel
authors.initials: CD
authors.lastname: Frisbie
keywords: copper electroless plating; flexible electronics; high-resolution metal lines; imprint lithography; inkjet printing