• Proceedings of the Korean Vacuum Society Conference
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• 2008.02a
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• pp.243-243
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• 2008

• Bulletin of the Korean Chemical Society
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• v.23 no.5
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• pp.699-704
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• 2002

We characterized nanoelectrode arrays prepared from self-assembled monolayers (SAMs) by adsorption from a solution containing thiolated $\beta$-cyclodextrin ($\beta$-CD) and n-alkanethiol on the gold electrode surface, using electrochemical methods. While the framework, the n-hexadecanethiol SAM, effectively blocked electron transfer between the electrode surface and solution-phase redox probe molecules, the $\beta$-CD cavities isolated in the forests of n-hexadecanethiol molecules were shown to act as an ultramicroelectrode array. The shapes of cyclic voltammograms of probe molecules were related to the number densities of $\beta$-CD molecules within the monolayer films. Probe molecules that have the correct combination of physical and chemical characteristics were shown to effectively penetrate the framework through the $\beta$-CD pores and exchange electrons with the electrode surface.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.385-389
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• 2010

This paper presents a microfabricated nanowire diluter which dilutes the concentration of nanowires in solution instead of by the conventional centrifuge process. The device has 16 pairs of gold electrodes in a micro channel composed of a glass substrate and PDMS. We prepared nickel nanowires by the template-directed electrodeposition method using nanoporous anodized aluminum template (AAO). We injected the Dimethylformamide (DMF) solution containing nanowires into the inlet of the diluter while applying square wave voltages on the electrodes to trap the nanowires at the subsequent gold electrodes by means of dielectrophoretic attraction forces. The concentration of nanowires at the outlet of the micro channel was changed as we expected, which illustrates that the device can effectively dilute nanowires and can be applied to a controlled assembly of nanowires.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1484-1485
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• 2008

The control of the number and dimension of nanowires is essential for dielectrophoretic(DEP) nanoscale assembly process. However, it is difficult to control the number of nanowires assembled between the electrodes. We have developed a nanowire diluter device, which consists of a glass substrate with gold electrodes and a PDMS layer with microchannel. The diluter device is fabricated by the conventional and soft lithographies using a SU-8 mold. Nickel nanowires (30${\mu}m$-long) are fabricated by a template-directed electrodeposition process using nanoporous alumina templates. A solution containing nanowires is injected into an inlet whereby pulsed voltages are applied to 16 pairs of electrodes in this experiment. The nanowires are trapped or released depending on the pulsed electric field from inlet to outlet (the channel). Therefore, the number of nanowires can be decreased correspondingly if the fixed frequency at each electrode is decreased from electrode to electrode.

• Korean Journal of Metals and Materials
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• v.56 no.12
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• pp.910-914
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• 2018

Since catalyst technology is one of the promising technologies to improve the working performance of next generation energy and electronic devices, many efforts have been made to develop various catalysts with high efficiency at a low cost. However, there are remaining challenges to be resolved in order to use the suggested catalytic materials, such as platinum (Pt), gold (Au), and palladium (Pd), due to their poor cost-effectiveness for device applications. In this study, to overcome these challenges, we suggest a useful method to increase the surface area of a noble metal catalyst material, resulting in a reduction of the total amount of catalyst usage. By employing block copolymer (BCP) self-assembly and nano-transfer printing (n-TP) processes, we successfully fabricated sub-20 nm Pt line and cross-bar patterns. Furthermore, we obtained a highly ordered Pt cross-bar pattern on a Ni thin film and a Pt-embedded Ni thin film, which can be used as hetero hybrid alloy catalyst structure. For a detailed analysis of the hybrid catalytic material, we used scanning electron microscope (SEM), transmission electron microscope (TEM) and energy-dispersive X-ray spectroscopy (EDS), which revealed a well-defined nanoporous Pt nanostructure on the Ni thin film. Based on these results, we expect that the successful hybridization of various catalytic nanostructures can be extended to other material systems and devices in the near future.