• Journal of Biomedical Engineering Research
• /
• v.43 no.4
• /
• pp.219-229
• /
• 2022

In this study, we propose a miniaturized micro-ceramic heater device. After screen-printing a silver paste between pre-sintered two aluminum oxide plates to integrate a heating circuit, the device was fabricated through a low-temperature sintering process. In order to configure the optimal heating circuit integration condition, the output current evaluation and heating test were performed according to the number of screen prints of the silver paste at various voltages. A silver paste-based heating circuit printed with a line width of 200 ㎛ and a thickness of 60 ㎛ was successfully integrated on a pre-sintered alumina substrate through a low-temperature sintering process. In the case of the 5 times printed device, the thermal response showed a response rate of 18.19 ℃/sec. To demonstrate feasibility of the proposed device in the medical field, such as bio-tissue suturing and hemostasis, a voltage was applied to pig tissue in the device to test tissue change due to heat generated from the device. These results show the possibility that the proposed small ceramic heater could be used in the medical field based on its excellent temperature response.

• Korean Journal of Environmental Agriculture
• /
• v.29 no.1
• /
• pp.72-76
• /
• 2010

We have developed the bio-electrode measuring the variance of the amount of acetylcholine affected by residual pesticide. The working electrode of the biosensor was made by combination of cobalt phthalocyanine and carbon organic compounds. The biosensors were constructed by screen-printing method. The principle of working electrode is similar to thiocholine sensor. We have fabricated the biosensor using standard screen printing method. Generally, the biosensor made by printing method formed thick film biosensor. When the electrodes were made by electrochemical cells, the generation of current by the addition of enzyme substrate was inhibited by standard solutions of organo-phosphate pesticides. The detection limit of sensor is about 0.5 $\mu{g}/L$ for carbofuran. We could improve the responsibility of the sensor by controlling the cobalt phthalocyanine and thiocholine concentration ratio. Also we have tested the EPN and Chlorpyrifos pesticides and found that the biosensor is applicable to fast determination of residual pesticides.

• Journal of Environmental Science International
• /
• v.16 no.8
• /
• pp.995-999
• /
• 2007

This study assessed the characteristics of emission and cell toxicology of Methylethylketone(MEK) in ambient air of industrial area. MEK is produced by the oxidation of sec-butyl alcohol and used as the solvent for making ink, printing, coating of film, bonding material and drug extraction. The MEK concentrations in the ambient-air of industrial area in Gimhae City was detected in the range of $25.4{\sim}1,580{\mu}g/m^3$ with an average $297.4{\mu}g/m^3$. The concentration of MEK showed a descending tendency from April to August followed by its increased tendency since then. The effects of MEK on the human lung cancer A549 cells was examined by the generation of Reactive Oxygen Species(ROS) and cytotoxicity. The range of MEK concentration detected in the area induced ROS generation affecting the oxidation state with a little effects on the viability of the cells.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.44 no.1
• /
• pp.16-23
• /
• 2012

Use of security papers for monetary papers, gift certificates, and lottery tickets increases every year. As the use of security papers increase, there are more possibility of counterfeits. In this study, we used unique fibers from the sea to increase the difficulties against counterfeiting. The red algae fibers give opacity as much as calcium carbonates, and have unique shape in length ($500{\sim}900\;{\mu}m$) and width ($1{\sim}4\;{\mu}m$) to be discerned from other natural fibers such as wood and cotton fibers. We mixed red algae fibers to wood fibers in a series of fixed ratios to make single and multiply papers for making security papers. Paper with dyed red algae fibers were also used. Paper made without fillers gave enough opacity for printing when red algae fibers were used more than 20% of the fiber furnish. Those properties may allow red algae fibers to be a potential candidate for fiber raw materials of security paper.

• Journal of Sensor Science and Technology
• /
• v.24 no.2
• /
• pp.119-123
• /
• 2015

This paper presents the inkjet-printed flexible temperature and humidity sensor(F-TH sensor) using PEDOT:PSS. The series, mesh and parallel type sensing element using PEDOT:PSS ink was printed on the overhead projector(OHP) film. The fabricated sensor of each structure has the temperature sensitivity of $140{\Omega}/^{\circ}C$, $29{\Omega}/^{\circ}C$ and $1.4{\Omega}/^{\circ}C$ with linearity, respectively. Also the fabricated sensor was not only possible to measure a temperature, but also to detect humidity. The humidity sensitivity of $400{\Omega}/%RH$, $3.4{\Omega}/%RH$ and $3{\Omega}/%RH$ with linearity, respectively. The fabricated F-TH sensor is expected for the various applications such as electronic devices, bio-healthcare, industrial field.

• Korean journal of applied entomology
• /
• v.61 no.1
• /
• pp.249-254
• /
• 2022

Silkworms, which have for long been used as an insect resource for industrialization, have recently attracted attention as potential bio-factories for the production of novel biomaterials. In this regard, material production is typically achieved based on transformation technology, mediated via microinjection, in which a target gene is inserted into eggs containing an embryo. However, an essential step in the microinjection procedure is egg fixation, which can be a time-consuming and laborious task. Therefore, in this study, using the 3DCADian program, we adopted a 3D printing approach to model egg liners and glue drawers, which can contribute to facilitating egg alignment and fixation, thereby enhancing transformation efficiency by reducing time consumption and fatigue. After rendering using Fusion 360, the two supplementary tools were produced by printing with nylon resin (PA12) and Sinterit Lisa Pro. Subsequent analysis of the time required to fix eggs on glass slides using the two manufactured tools, revealed that the processing time was reduced by approximately 18.6% when the two tools were used compared with when these tools were not used. These innovations not only reduced fatigue but also contributed to more effective use of the microscope and manipulator for microinjection. Consequently, we believe that with additional research and refinement, the egg liner and glue drawer developed in this study could be used to enhance silkworm transformation efficiency and study similar transformation systems in other industrial insects.

• Proceedings of the IEEK Conference
• /
• 2002.07b
• /
• pp.987-990
• /
• 2002

Fine grayscale data exceeding 8 bits per pixel is mapped into the sRGB color space so as to be displayed on a 24-bit sRGB CRT monitor. The characteristics of the pseudo gray generated by mapping are investigated in terms of the CIELAB color difference and chromaticities.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.1472-1475
• /
• 2009

The microfluidics channel were fabricated using thermal roll-imprinting process on plastic substrates. As rollimprinting surface is heated directly at $100^{\circ}C$ and printing process proceed 380/400 kgf pressure, we fabricated microfluidic patterns separated line of $40.04{\mu}m$, serpentine line of $113.89{\mu}m$ and depth of imprint pattern is $15.35{\mu}m$, it means to get fine pattern has more than 70% imprint rate in designed mask.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.22 no.2
• /
• pp.117-136
• /
• 2020

The purpose of this study is to analyze changes in high-tech fashion along with the types and characteristics of high-tech fashion that have appeared recently providing diverse material for the fashion field. High-tech fashion requires such research to learn how much distance one has in one's life. It is also meaningful to predict what direction high-tech fashion research may be needed. For research methods, previous research and literary studies were considered and photographs in which high-tech techniques were used were collected using the keyword 'high-tech fashion'. High-tech fashion types can be organized into the four types of luminescent types, mutual interaction types, 3D printing fashion, and virtual fashion. The research results were as follows. First, luminescent fashion was an important expression method of high-tech fashion. Materials for luminescent fashion first started with LED electric wire connections and many methods have been attempted with the appearance of electrically conductive clothing material, such as luminescent lasers and beam projectors. Second, interactive high-tech fashion often appears as variable fashion. The work of Hussein Chalayan, which was combined with advanced technology, set up a base for variable type interactive high-tech fashion in the 2000s. As bioengineering technology has developed, fashion that interacts with the environment without an energy source has appeared and the interaction among fashion, people, and the environment can be seen. Third, diverse forms of expressiveness in virtual reality such as 3D CLO shows a great difference with past high-tech fashion. Simple and diverse attempts made through virtual fittings reduce the limitations of time and space, permit interaction, and add a sense of reality through speed and dynamic physical beauty. Fourth, 3D printed fashion expresses complex and detailed clothing material that is different from those before with the development of computer 3D modeling technology. Modeling that can imitate geometric and bio-engineered structures is possible and mysterious feelings are passed on to people through creative expressions.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.632-637
• /
• 2021

In order to develop future construction technology, research is actively being conducted on concrete construction technology using 3D printing, which is currently in the spotlight as a future industry in domestic and foreign construction industries and academia. However, 3D printing technology is currently being developed and does not meet the requirements for proper construction technology and the properties of concrete materials, and it is difficult to apply in the actual field. Research is also needed for the durability management and maintenance of constructed structures. This work compares the compressive and flexural strength to that produced in conventional molds by dividing the 3D printed concrete output by the laminated X, Y, and Z axes. The compressive strength of a test specimen in the II Z-axis test direction was 8-10% higher than that of the other test directions (I and III Y axes and X axis). The strength was 4% lower than that of a molded test specimen. As of 28th of the age, the bending strength of the test specimen in the Z-axis direction was 5 to 7% higher than that of the I and III Y, and X-axis test directions, and the strength was 2% lower than that of the molded test specimen.