Casting metal microstructures from a flexible and reusable mold

• Published in: Journal of micromechanics and microengineering 2009-09, Vol.19 (9), p.095016-095016 (6)
• Main Authors: Cannon, Andrew H, King, William P
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Foundry engineering; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Metals. Metallurgy; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Other casting methods. Solidification; Physics; Precision engineering, watch making; Production techniques; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/19/9/095016

This paper describes casting-based microfabrication of metal microstructures and nanostructures. The metal was cast into flexible silicone molds which were themselves cast from microfabricated silicon templates. Microcasting is demonstrated in two metal alloys of melting temperature 70 deg C or 138 deg C. Many structures were successfully cast into the metal with excellent replication fidelity, including ridges with periodicity 400 nm and holes or pillars with diameter in the range 10-100 mum and aspect ratio up to 2:1. The flexibility of the silicone mold permits casting of curved surfaces, which we demonstrate by fabricating a cylindrical metal roller of diameter 8 mm covered with microstructures. The metal microstructures can be in turn used as a reusable molding tool.