Facile fabrication of flexible electronics via direct laser writing of carbon-silver nanocomposite

Abstract

In this paper, we demonstrate a facile method for the fabrication of porous-carbon/silver nanocomposites using direct laser writing on polymeric substrates. Our technique uses a combination of CO2 laser-induced carbonization and selective silver deposition on a polyimide sheet to create flexible highly conductive traces. The localized laser irradiation selectively converts the polyimide to a highly porous and conductive carbonized film with superhydrophilic wettability. The resulting pattern allows for selective trapping of aqueous silver ionic ink solutions into the carbonized regions that are subsequently converted to Ag/C nanocomposite with sheet resistance as low as, upon annealing. The resulting patterns are flexible and electromechanically robust with less than 0.6 Ω variation in resistance after > 15000 flexion bending cycles. Furthermore, using this technique, we demonstrate the fabrication of a wireless resonant pressure sensor capable of detecting pressures ranging from 0 to 97 kPa with an average sensitivity of −26 kHz/kPa.