• Korea Journal of Cosmetic Science
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• v.2 no.1
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• pp.21-31
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• 2020

The aim of this study is to develop a sunscreen stick formulation technology with excellent water resistance and washability. Consumers' needs for sunscreen products are diversifying. Water resistance and ease of washing are both important factors in sunscreen products. However, it is difficult to develop a sunscreen formulation that satisfies these two factors at the same time, because these two elements are in conflict. Fatty acid has a hydrophobic property against the water with low or neutral pH, but when it contacts with soapy water which has high pH, saponification occurs and the fatty acids become surfactants and can be dispersed in the water. Using the reaction characteristics of fatty acids, we can make sunscreen that is highly resistant to water or sweat, but is only selectively removed from soapy water. We found that the sunscreen stick containing fatty acids had better water resistance and washability than the sunscreen sticks without fatty acid. The sunscreen stick containing fatty acids showed a tendency to improve water resistance by scattering ultraviolet rays of long wavelength area by forming insoluble precipitation with divalent ions in tap water after immersion. In addition, an increase in the fatty acid content tended to also increase the ease of cleaning the sunscreen stick. Solid fatty acid was advantageous in improving water resistance than liquid fatty acid, but there was no difference between solid fatty acids and liquid fatty acid in washability. When it comes to stability, the sunscreen stick using liquid fatty acids maintained a high hardness and melting point, and showed no sweating. Based on this study, it is possible to develop an easy washable sunscreen stick formulation technology that has excellent water resistance but is selectively removed only in soapy water.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.10
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• pp.1114-1120
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• 2009

The conductivity of various electro-threads is analyzed, and the washable electro-thread embroidery UHF RFID tag antennas using the character shape without T-matching structure are designed by adding a T-matching structure. The RFID tag antenna using the electro-thread is easy to be embedded on a cloth as a wearable antenna because it is flexible and different from general copper inlay shape and tape type tag. The embroidery tag antennas are designed with the English alphabet 'F' and the Korea alphabet 'ㄹ' character. Those are easy to be applied to general clothes. The parameters of antennas are optimized and fabricated. The characteristics and the reading range patterns of the tag antennas are measured. The reading ranges of wet tags(tap water, sea water and soapy water) are tested and compared.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.5
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• pp.527-536
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• 2011

Diabetics often suffer from the complications of foot disease. Foot discomfort results from poor blood circulation. Thus, diabetics should wear socks that do not constrict the blood flow in the feet and legs. This study examines the design factors and performance requirements of socks for diabetics. We apply the results to the development of socks for diabetic. The participants in this study were 112 diabetic patients who had visited a hospital in Busan. We conducted statistical tests that included t-tests and chi-squared tests. The results depended on age and gender. Male and female patients did not differ from each other in the most favorite style; however, their second favorite style was different. The second most preferred style for male patients was calf-length socks, while the second most preferred style for female patients were ankle-length socks. Male patients preferred black or gray socks, while female patients preferred white socks. Socks for diabetics should be machine washable, easy to remove, non-slip, lightweight, comfortable, deodorized, and antibacterial.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.2 s.161
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• pp.292-299
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• 2007

Development of portable device measuring the vital sign continuously with no limit of time and space is absolutely prerequisite for the U-health care that grafts the ubiquitous concept into medical system. Accordingly, it requires to develop a garment style apparatus for measuring vital-sign that is easy to wear on for a long time period. This study suggests a method to improve the insulation of electric cable and the skin adhesion of electrode by integrating the electric conductive material to garment, in order to develop a garment apparatus for measuring ECG for U-health care. Results of the research are as follows; In order to provide the adjacent conductive yarns with insulation, braid with narrow woven end was interlaced using polyester yarn. As a result, the direct contact between electric conductive yarns was restrained, which would be interposed into pin-tuck structured cable. Washable silicone gel applied around the electrode made of electric conductive fabric improved the adhesion, which prevents electrodes from dropping off from the skin surface during body movement. ECG signals on the human subject were tested using the garment apparatus developed by the above method. And the result was that the clear QRS wave formation in the typical form of ECG could be measured in both conditions of still and moving state as well. The result of this study is expected to contribute for the production of U-health care related medical apparatus by accelerating the practical uses of the garment measuring vital sign at a reasonable price.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.413-413
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• 2014

In this paper, we present a fabrication method of functionalized gold nanostructures on flexible substrate that can be implemented for plasmonic sensing application. For biomolecular sensing, many researchers exploit unconventional lithography method like nanoimprint lithography (NIP), contact transfer lithography, soft lithography, colloidal transfer printing due to its usability and easy to functionalization. In particular, nanoimprint and contact transfer lithography need to have anti-adhesion layer for distinctive metallic properties on the flexible substrates. However, when metallic thin film was deposited on the anti-adhesion layer coated substrates, we discover much aggravation of the mold by repetitive use. Thus it would be impossible to get a high quality of metal nanostructure on the transferred substrate for developing flexible electronics based transfer printing. Here we demonstrate a method for nano-pillar mold and transfer the controllable nanoparticle array on the flexible substrates without an anti-adhesion layer. Also functionalization of gold was investigated by the different length of thiol applied for effectively localized surface plasmonic resonance sensing. First, a focused ion beam (FIB) and ICP-RIE are used to fabricate the nanoscale pillar array. Then gold metal layer is deposited onto the patterned nanostructure. The metallic 130 nm and 250 nm nanodisk pattern are transferred onto flexible polymer substrate by bi-layer functionalized contact imprinting which can be tunable surface energy interfaces. Different thiol reagents such as Thioglycolic acid (98%), 3-Mercaptopropionic acid (99%), 11-Mercaptoundecanoic acid (95%) and 16-Mercaptohexadecanoic acid (90%) are used. Overcoming the repeatedly usage of the anti-adhesion layer mold which has less uniformity and not washable interface, contact printing method using bi-layer gold array are not only expedient access to fabrication but also have distinctive properties including anti-adhesion layer free, functionalized bottom of the gold nano disk, repeatedly replicate the pattern on the flexible substrate. As a result we demonstrate the feasibility of flexible plasmonic sensing interface and anticipate that the method can be extended to variable application including the portable bio sensor via mass production of stable nanostructure array and other nanophotonic application.