Fabrication of high-resolution conductive lines by combining inkjet printing with soft lithography

Abstract

In this study, an effective method to fabricate well-defined conductive lines with high resolution has been proposed by combining inkjet printing with soft lithography. Soft lithography techniques such as nano-imprint lithography for negative SU-8 patterns and micro-contact printing for hydrophobic fluorocarbon layer were used to create surface wettability contrasts so that the spreading of droplets was confined on a hydrophilic region surrounded by hydrophobic regions. Surface wettability contrasts were evaluated by water contact angle measurements, and the maximum contact angle difference between hydrophobic and hydrophilic surfaces was 104^o. With the help of such surface wettability contrasts and lift-off process for removing small amount of ink stains, well-defined inkjet-printed lines as narrow as [email protected] can be successfully generated. The sintered Ag lines also show good electrical resistivity of [email protected]@W.cm, 4.7 times as large as bulk Ag's resistivity. This combined approach can be used to fabricate high-quality, high-resolution electrodes in printed electronics applications.