Solution-based, flexible, and transparent patterned reduced graphene oxide electrodes for lab-on-chip applications.

The fabrication of patterned reduced graphene oxide (rGO) thin films by dispersion of graphene oxide (GO) solution on different substrates is demonstrated. The GO films are deposited on substrates and patterned using plasma-enhanced liftoff techniques. The substrate is initially treated with oxygen plasma to increase surface energy and enhance wettability thus increasing the bond between the GO flakes and the substrate. The GO film is then deposited on the substrate from a GO aqueous solution via a spin coating approach. Photolithography is then used to pattern the GO film. Finally, the GO film is chemically reduced to rGO using hydroiodic acid. The fabrication method is found to be very compatible with polymer substrates. In addition, the developed patterned rGO electrodes are employed in manipulating living cells in a microfluidic device using dielectrophoresis.