Effect of Surface Property on Transfer-Print of Au Thin-Film to Micro-Structured Substrate

This present study describes a novel micro-fabrication technique using transfer-print of thin-film for micro-mechanical structure. Some thin-films of Au have been transferred from a stamp onto pre-structured micro-ridges of polymer substrate. These thin-films successfully form into an array of fixed micro-beams as a mechanical structure. The fabricated micro-beams typically have a thickness of less than 100 nm and a tens micro-meter long. This present paper also reports an investigation about effects of stamp surface properties. A modification of stamp surface wettability and roughness improves adhesive force (releasability) of thin-film to provide flat micro-beam without undesired deformations. Hydrophobic stamp with micro-roughness results in an increase of production yield of micro-beams to reach more than 90%. Simple mechanical test shows that the fabricated micro-beam is transversely tensioned by the supporting micro-ridges of substrate. It is clarified that the proposed process can be applied to fabricate micro/nano-mechanical elements.