• Korean Chemical Engineering Research
• /
• v.59 no.1
• /
• pp.100-105
• /
• 2021

This paper proposes the polydimethylsiloxane (PDMS) blade coating method for fabrication of paper-based analytical device (PAD) that is able to monitor the disease diagnosis and progress without special analytical equipment. The mold that has PAD design is easily modified by using laser cutting technique. And the fabricated mold is used for hydrophobic barrier formation by blade coating. We have optimized the stable formation of PDMS hydrophobic barrier as blade coating condition, which is established by analyzing the structure of the PDMS hydrophobic barrier and change of hydrophilic channel size as thickness of the ink and contact time with the chromatography paper. Based on optimal condition, we demonstrate that PAD as biosensor can apply to detect protein, glucose, and metal ion without special analysis equipment.

• Fashion & Textile Research Journal
• /
• v.24 no.1
• /
• pp.95-107
• /
• 2022

In reality, the distinction between the Korean traditional culture and the cultures of other countries is at a delicate boundary. Additionally in the wake of the recent socio-cultural confrontation between Korea and China, it has become necessary to establish the foundation and area of Korean traditional culture and to actively utilize the importance of improving awareness of Korean traditional culture. To reorganize the reckless use of the gold foil pattern shown in the rental hanbok, data on the museum's collection of gold leaf patterns were collected and analyzed. Based on the gold foil, Gilsang characters such as Phoenix pattern, Crane pattern, Bat pattern, Flower pattern, Fruit pattern and recovery advice were extracted through references. The traditional gold foil pattern was reconstructed and relocated to design the gold leaf patch. Based on the collection and analysis of the museum's relics, the Wonsam & Daedae, Dangeui, Sranchima, Sagyusam, Jeonbok, Bokgun, and Daenggi were produced. Therefore, we present the possibility of producing gold foil and modern methods for producing gold foil using laser cutting techniques that can express refinement and complexity well, and gold foil thermal transfer paper with retouchable effects. Additionally, we would like to reflect upon the practicality and the convenience to modern people by considering the complexity and hassle of the traditional gold foil production process, and the disadvantages of processes that require relatively longer time. It intends to help revitalize the market of Korean traditional clothing and fashion products.

• Journal of Korean Ophthalmic Optics Society
• /
• v.13 no.4
• /
• pp.75-81
• /
• 2008

Purpose: To develop a solar concentrator having the reflecting surface with the 2m class diameter. Methods: In order to make the reflecting surface for the solar concentrator, the shape of the reflecting surface sector is required. So, first, we induced the formula that can produce this shape. After that, using Delphi 6.0 language, we developed a program which uses this formula and produces the shape and the numerical data of the reflecting surface sector with the input variables such as the external diameter of the reflecting mirror, the reflecting mirror's radius of curvature at the paraxial range, the number of reflecting mirror sector, the size of the center hole of the reflecting mirror, and the interval of the output data. Results: This program, which was developed to produce the shape and the numerical data of the reflecting surface sector, enables us to see the shape of sector on the monitor and to save the numerical data files for the shape of sector. As a result, the user of this program can easily access the numerical data of the reflecting surface sector. Conclusions: Developing the program which produce the reflecting surface sector used to make the reflecting surface of the solar concentrator, we could succeed in making the prototype products by applying it to the development of the real solar concentrator with the diameter of the 2m class.

• Journal of The Korean Association of Information Education
• /
• v.23 no.1
• /
• pp.73-84
• /
• 2019

Maker movement is emerging as one of the key areas of the fourth industrial revolution in recent years. The maker movement is to create and share what users need using a variety of inexpensive production tools such as open source software and hardware, 3D printers and laser cutters. We think that the effect would be enhanced if design thinking is applied to elementary and middle school (K-12) class. The purpose of this study is to develop a design thinking-based maker education program and to apply it to classroom for clarify the effect on the creative problem solving ability of elementary school students. In order to verify the purpose of the research, students in the 5th-6th grades of elementary school were divided into a controlled group and an experimental group. The general lecture maker class was applied in the controlled group, and our developed design thinking-based maker class was simultaneously applied in the experimental group. The creative problem solving ability test was conducted before and after the test, and its effectiveness was verified using statistical t-test. In conclusion, this study suggests that design thinking-based maker education program has a positive effect on elementary school students' creative problem solving ability.

• Clean Technology
• /
• v.28 no.4
• /
• pp.323-330
• /
• 2022

Microfluidic paper-based analytical devices (μPADs) have recently been in the spotlight for their applicability in point-of-care diagnostics and environmental material detection. This study presents a double-sided printing method for fabricating 3D-μPADs, providing simple and cost effective metal ion detection. The design of the 3D-μPAD was made into an acryl stamp by laser cutting and then coating it with a thin layer of PDMS using the spin-coating method. This fabricated stamp was used to form the 3D structure of the hydrophobic barrier through a double-sided contact printing method. The fabrication of the 3D hydrophobic barrier within a single sheet was optimized by controlling the spin-coating rate, reagent ratio and contacting time. The optimal conditions were found by analyzing the area change of the PDMS hydrophobic barrier and hydrophilic channel using ink with chromatography paper. Using the fabricated 3D-μPAD under optimized conditions, Ni²⁺, Cu²⁺, Hg²⁺, and pH were detected at different concentrations and displayed with color intensity in grayscale for quantitative analysis using ImageJ. This study demonstrated that a 3D-μPAD biosensor can be applied to detect metal ions without special analysis equipment. This 3D-μPAD provides a highly portable and rapid on-site monitoring platform for detecting multiple heavy metal ions with extremely high repeatability, which is useful for resource-limited areas and developing countries.