• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.272-274
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• 2005

A simple method for fabricating micro/nanoscale hierarchical structures is presented using a two-step temperature-directed capillary molding technique. This lithographic method involves a sequential application of molding process in which a uniform polymer-coated surface is molded with a patterned mold by means of capillary force above the glass transition temperature of the polymer. Using this approach, multiscale hierarchical structures for biomimetic functional surfaces can be fabricated with precise control over geometrical parameters and the wettability of a solid surface can be designed in a controllable manner.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.426-428
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• 2007

A simple method is presented for fabricating micro/nanoscale combined hierarchical structures using a two-step UV-assisted capillary molding technique. This lithographic method consists of two steps: (i) fabrication of partially cured polymer microstructures using a PDMS mold and (ii) subsequent nanofabrication using a high-resolution polyurethane acrylate (PUA) mold on top of the pre-formed microstructures. Using this technique, various micro/nano hierarchical structures were fabricated with minimum resolution down to 70 nm over a large area with very good reproducibility.

• Journal of Mechanical Science and Technology
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• v.19 no.2
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• pp.649-654
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• 2005

This paper presents fabrication and drive test of a peristaltic PDMS micropump actuated by the thermopneumatic force. The micropump consists of the three peristaltic-type actuator chambers with microheaters on the glass substrate and a microchannel connecting the chambers and the inlet/outlet port. The micropump is fabricated by the spin-coating process, the two-step curing process, the JSR (negative PR) molding process, and etc. The diameter and the thickness of the actuator diaphragm are 2.5 mm and $30{\mu}m$, respectively. The meniscus motion in the capillary tube is observed with a video camera and the flow rate of the micro pump is calculated through the frame analysis of the recorded video data. The maximum flow rate of the micropump is about $0.36\;{\mu}L/sec$ at 2 Hz for the zero hydraulic pressure difference when the 3-phase input voltage is 20 V.