Ionic Liquid Thin Film Fabrication Using Nano-Inkjet Printing Method

Nanometer-scale liquid droplets and a liquid film patterned with a controlled thickness using an ionic liquid thin film were successfully deposited by a newly developed nanoinkjet printing method based on atomic force microscopy (AFM). Liquid droplets were locally deposited through an aperture with a diameter of 200 nm adjacent to an AFM tip by applying an electric field between a cantilever backside coating and a conductive substrate. The liquid film was fabricated by depositing an array of droplets with a spacing smaller than 70 nm and by the AFM tip effect. The deposited thin film has a layer-by-layer structure with a layer thickness of 4 nm. In addition, we also succeeded in the deposition of yoctoliter-scale liquid droplets, having only several tens of the liquid molecules inside, by applying an AC voltage. (C) 2010 The Japan Society of Applied Physics