Conductive and transparent gel microstructures fabricated by inkjet printing of ionic liquid based fluids

Ionic liquid-polymer gel microstructures with high spatial resolution (line widths of 35 - 40 μm), good electrical conductivity (5 - 30 mS/cm), optical transparency and mechanical flexibility are fabricated using a new and solvent-free inkjet printing process. Homogeneously gelled structures are achieved by carrying out the printing and polymerization process in nitrogen atmosphere eliminating the inhibiting influence of oxygen. Printable low viscosities are achieved without adding extra solvents by the careful selection and combination of ionic liquids (ILs) and unsaturated monomers. The final properties of the printed IL-polymer gels can be controlled in terms of ionic conductivity, optical transmission and mechanical flexibility by using different types and amounts of ILs and monomers.