Fig. 2: Mechanism and fabrication details of two-dimensional nanotransfer printing on the elastomer substrate.

a Schematic mechanism of nanotransfer. The area enclosed by a red dotted line shows the effect of O₂ plasma treatment on the mold with the target material, and the area enclosed by a blue dotted line shows the chemical reactions of the adhesion promoter during nanotransfer printing. b Schematic effects of material properties on material transferability during nanotransfer printing. Materials with weak intrinsic adhesion to the mold can be transferred directly (area enclosed by the green line), while those with strong intrinsic adhesion require a supporting layer (e.g., Au) for transfer (area enclosed by the red line). c Side-view scanning electron microscopy images of the mold with the target material before and after 30-min treatment with O₂ plasma. d Effects of the linewidth of the mold nanopattern on the possible range and optimum of O₂ plasma treatment time suitable for transfer. Here, a transferable condition is defined as a condition in which 50% or more of the target region is transferred and an optimal condition is defined as a condition in which 80% or more of the target region is transferred. e Scanning electron microscopy images of nanoline patterns with linewidths of 50 nm and 2 µm nanotransfer-printed on a flat elastomer substrate. f Confocal laser scanning microscopy and scanning electron microscopy images of a nanoline array with a linewidth of 800 nm nanotransfer-printed on the micropatterned elastomer substrate. The triangular region of the confocal laser scanning microscopy image denotes the suspended (trench) part.