Single-anchor support and supercritical CO2 drying enable high-precision microfabrication of three-dimensional structures

In high-precision two-photon microfabrication of threedimensional (3-D) polymeric microstructures, supercritical CO2 drying was employed to reduce surface tension, which tends to cause the collapse of micro/nano structures. Use of supercritical drying allowed high-aspect ratio microstructures, such as micropillars and cantilevers, to be fabricated. We also propose a single-anchor supporting method to eliminate non-uniform shrinkage of polymeric structures otherwise caused by attachment to the substrate. Use of this method permitted frame models such as lattices to be produced without harmful distortion. The combination of supercritical CO2 drying and the single-anchor supporting method offers reliable high-precision microfabrication of sophisticated, fragile 3-D micro/nano structures. (C) 2009 Optical Society of America