InkjetPrinting Patterns of Highly Conductive PristineGraphene on Flexible Substrates.

Highlyconductive pristine graphene electrodes were fabricatedby inkjet printing using ethyl cellulose-stabilized ink prepared frompristine graphene. Pristine graphene was generated by exfoliationfrom graphite using ultrasound-assisted supercritical CO2. The ink, at concentrations up to 1 mg/mL, was stable for more than9 months and had compatible fluidic characteristics for efficientand reliable inkjet printing. The inkjet printing patterns of thegraphene on diverse substrates were uniform and continuous. After30 printing passes and annealing at 300 °C for 30 min, the printedfilms developed a high conductivity of 9.24 × 103S/m.The resistivity of the printed electrodes on the flexible substratesincreased by less than 5% after 1000 bending cycles and by 5.3% undera folding angle of 180°. The presented exfoliated pristine grapheneand the corresponding efficient methods for formulating the ink andfabricating conductive electrodes are expected to have high potentialin applications involving graphene-based flexible electronic devices. [ABSTRACT FROM AUTHOR]