Environmentally Friendly Graphene Inks for Touch Screen Sensors

Graphene-based materials have attracted significant attention in many technological fields, but scaling up graphene-based technologies still faces substantial challenges. High-throughput top-down methods generally require hazardous, toxic, and high-boiling-point solvents. Here, an efficient inexpensive strategy is proposed to produce graphene dispersions by liquid-phase exfoliation (LPE) through a combination of shear-mixing (SM) tip sonication (TS) techniques, yielding highly concentrated inks compatible with spray coating. The quality flakes (e.g., lateral size thickness) their concentration the are compared using different spectroscopic microscopy techniques. Several approaches (individual SM TS, combination) tested three solvents (N-methyl-2-pyrrolidone, dimethylformamide, cyrene). Interestingly, TS cyrene yields high-quality dispersions, overcoming environmental issues linked other two Starting from dispersion, ink prepared spray-coat flexible electrodes assemble touch screen prototype. feature low sheet resistance (290 ? ??1) high optical transmittance (78%), which provide prototype signal-to-noise ratio (14 dB) multi-touch functionality (up four simultaneous touches). These results illustrate potential pathway toward integration LPE-graphene commercial electronics.