Surface-Patterning of Nanocomposite Hydrogel Film by Direct Replica Molding and Subsequent Change in Pattern Size

Using PNIPA nanocomposite hydrogel (NC gel), which exhibits extraordinary mechanical toughness as well as high transparency and good thermal sensitivity, micrometer-scale surface-patterned NC gel films were successfully prepared by direct replica molding (direct REM) without any chemical surface treatment of the template. The surface pattern and its changes were characterized based on 3-D images and 2-D profiles generated by confocal optical microscopy. It was found that small (similar to 1 mu m) microstructures were precisely transferred onto the surfaces of the NC gel films without defect, and that the size of the patterns could be modified (enlarged or miniaturized) by Subsequent swelling, deswelling and drying without disturbing the patterns.