• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.273-273
• /
• 2013

Recently, Point-of-care (POC) testing microdevices enable to do the patient monitoring, drug screening, pathogen detection in the outside of hospital. Immunochromatographic strip (ICS) is one of the diagnostic technologies which are widely applied to POC detection. Relatively low cost, simplicity to use, easy interpretations of the diagnostic results and high stability under any circumstances are representative advantages of POC diagnosis. It would provide colorimetric results more conveniently, if the genetic analysis microsystem incorporates the ICS as a detector part. In this work, we develop a reverse transcriptase-polymerase chain reaction (RT-PCR) microfluidic device integrated with a ROSGENE strip for colorimetric influenza H1N1 virus detection. The integrated RT-PCR- ROSGENE device is consist of four functional units which are a pneumatic micropump for sample loading, 2 ${\mu}L$ volume RT-PCR chamber for target gene amplification, a resistance temperature detector (RTD) electrode for temperature control, and a ROSGENE strip for target gene detection. The device was fabricated by combining four layers: First wafer is for RTD microfabrication, the second wafer is for PCR chamber at the bottom and micropump channel on the top, the third is the monolithic PDMS, and the fourth is the manifold for micropump operation. The RT-PCR was performed with subtype specific forward and reverse primers which were labeled with Texas-red, serving as a fluorescent hapten. A biotin-dUTP was used to insert biotin moieties in the PCR amplicons, during the RT-PCR. The RT-PCR amplicons were loaded in the sample application area, and they were conjugated with Au NP-labeled hapten-antibody. The test band embedded with streptavidins captures the biotin labeled amplicons and we can see violet colorimetric signals if the target gene was amplified with the control line. The off-chip RT-PCR amplicons of the influenza H1N1 virus were analyzed with a ROSGENE strip in comparison with an agarose gel electrophoresis. The intensities of test line was proportional to the template quantity and the detection sensitivity of the strip was better than that of the agarose gel. The test band of the ROSGENE strip could be observed with only 10 copies of a RNA template by the naked eyes. For the on-chip RT-PCR-ROSGENE experiments, a RT-PCR cocktail was injected into the chamber from the inlet reservoir to the waste outlet by the micro-pump actuation. After filling without bubbles inside the chamber, a RT-PCR thermal cycling was executed for 2 hours with all the microvalves closed to isolate the PCR chamber. After thermal cycling, the RT-PCR product was delivered to the attached ROSGENE strip through the outlet reservoir. After dropping 40 ${\mu}L$ of an eluant buffer at the end of the strip, the violet test line was detected as a H1N1 virus indicator, while the negative experiment only revealed a control line and while the positive experiment a control and a test line was appeared.

• Journal of Sensor Science and Technology
• /
• v.29 no.5
• /
• pp.354-359
• /
• 2020

The high vacuum hermetic sealing technique ensures excellent performance of MEMS resonators. For the high vacuum hermetic sealing, the customization of anodic bonding equipment was conducted for the glass/Si/glass triple-stack anodic bonding process. Figure 1 presents the schematic of the MEMS resonator with triple-stack high-vacuum anodic bonding. The anodic bonding process for vacuum sealing was performed with the chamber pressure lower than 5 × 10^-6 mbar, the piston pressure of 5 kN, and the applied voltage was 1 kV. The process temperature during anodic bonding was 400 ℃. To maintain the vacuum condition of the glass cavity, a getter material, such as a titanium thin film, was deposited. The getter materials was active at the 400 ℃ during the anodic bonding process. To read out the electrical signals from the Si resonator, a vertical feed-through was applied by using through glass via (TGV) which is formed by sandblasting technique of cap glass wafer. The aluminum electrodes was conformally deposited on the via-hole structure of cap glass. The TGV process provides reliable electrical interconnection between Si resonator and aluminum electrodes on the cap glass without leakage or electrical disconnection through the TGV. The fabricated MEMS resonator with proposed vacuum packaging using three-layer anodic bonding process has resonance frequency and quality factor of about 16 kHz and more than 40,000, respectively.

• Korean Journal of Optics and Photonics
• /
• v.15 no.4
• /
• pp.325-330
• /
• 2004

We fabricated a vacuum ultraviolet spectre-reflectometer which consists of a deuterium light source, a vacuum monochromator, and a sample chamber and detector module. The operation was performed in the ultraviolet spectral ranges between 115 nm and 330 nm at the vacuum pressure of 3.0 ${\times}$ 10$^{-4}$ Pa. The wavelength of the vacuum monochromator was calibrated with the line spectrum of a low pressure Mercury lamp of 253.652 nm and 184.95 nm wavelengths, and its resolution was 0.012 nm, and the precision of wavelength was $\pm$ 0.03 nm. With this reflectometer and a deuterium lamp, we measured the spectral regular transmittance and reflectance of materials(MgF$_2$, CaF$_2$, BaF$_2$, SiO$_2$, Sapphire) used as optical components over the spectral range between 115 nm and 230 nm.

• Journal of the Korean Geosynthetics Society
• /
• v.3 no.1
• /
• pp.17-25
• /
• 2004

A horizontal drain method, which applies vacuum pressure at the end of a horizontal drain for discharging pore water, is used often for improving surface reclaimed clay in the field. In this study, to examine the effectiveness of improving consolidation or shear strength depends by varying vacuum pressure, laboratory chamber horizontal drain test using vacuum pressure is performed and the results is compared with that of self-weight consolidation. The results show that water content reduces with the increase of soil depth in case of self-weight consolidation, while it reduces near the horizontal drain and increases with the increase of the distance from the horizontal drain in case of applying vacuum pressure. The shear strength of dredged soil was improved as well, when the vacuum pressure is applied. The optimized consolidation was achieved at the vacuum pressure range of 30 to 50kPa in the laboratory box test of 50cm wide, considering the range of drain interval in the field was between 0.7 and 1.2m.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.52 no.3
• /
• pp.130-136
• /
• 2003

Crowbar system Vacuum switches, widely used In a pulsed power system, could use the magnetic force to prevent the electrode damage. Vacuum switches using the magnetic forces are classified roughly into RMF(Radial Magnetic Field) and AMF(Axial Magnetic Field) type. The RMF type switches restrain a main electrode from aging due to high temperature and high density arc by rotating the arc which is driven by the Lorenz force. The AMF type switches generate axial magnetic field which decreases the electrode damage by diffusing arc. In this paper, we present the energy loss characteristics of both RMF and AMF type switches which are made of CuCr(75:25 wt%) electrodes. The time-dependent dynamic arc resistance of high-current pulsed discharge in a high vacuum chamber(~10$^{-6}$ Torr). which occurs in RMF and AMF type switches, was obtained by solving the circuit equation using the measured values of the arc voltage and current. In addition, we compared energy loss characteristics of both switches. Based on our results, it was found that the arc voltage and the energy loss of an AMF type switch are lower than a RMF type switch.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.870-873
• /
• 2003

We have fabricated a carbon nanotube field emission display(CNT FED) panel with a 2 inch diagonal size by using screen printing method and vacuum in-line sealing technology. The sealing temperature of the panel was around 390 $^{\circ}C$ and the leak test was carried out for 72 hrs after sealing process. When field emission properties of fabricated and sealed CNT FED panel were characterized and compared with those of unsealed panel which was located in vacuum chamber of vacuum level similar with the sealed panel, the sealed panel showed more improved field emission properties.

• Journal of Information Display
• /
• v.4 no.3
• /
• pp.6-11
• /
• 2003

We have fabricated a carbon nanotube field emission display (CNT-FED) panel with a 2-inch diagonal size by using a screen printing method and vacuum in-line sealing technology. The sealing temperature of the panel was around 390$^{\circ}C$ and the vacuum level was obtained with 1.4x$10^{-5}$torr at the sealing. When the field emission properties of a fabricated and sealed CNT-FED panel were characterized and compared with those of the unsealed panel which was located in a test chamber of vacuum level similar with the sealed panel. As a result, the sealed panel showed similar I-V characteristics with unsealed one and uniform light emission with very high brightness at a current density of 243 ${\mu}A/cm^2$, obtained at the electric field of 10 V/${\mu}m$.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.19 no.3
• /
• pp.365-369
• /
• 2010

Magnetic fluid seal is characterized by its simple design, low friction and being dustless. Those advantages are deduced from the fact that the sealing element is not a solid such as rubber or plastic but it is a fluid. Those are critical for application to a rotating shaft which is inserted into a vacuum chamber where high level of vacuum and cleanness are required. For the reason the magnetic fluid seal has become a standard for vacuum chambers for semiconductor and LCD processing. It should be noted that its sealing performance is sensitive to temperature. If necessary, water cooling should be considered. Thus anticipation of the temperature distribution of the magnetic fluid seal is important before applying it. In this paper an FEM analysis of the heat transfer has been executed and compared with experimental results. An overall convective heat transfer coefficient has been adopted for the analysis, which results in satisfactory consistency of the theoretical and experimental results.

• Journal of Aerospace System Engineering
• /
• v.1 no.4
• /
• pp.37-41
• /
• 2007

Labyrinth seal is most common way to protect the bearings installed in Reaction wheel. In spite of wide applications, no such research was found about the sealing utility of the Labyrinth seal in the condition of vacuum and high temperature. In this research, we tried to verify the utility of Labyrinth seal. Numerical analysis had been executed to predict the benefit of the Labyrinth seal and also experiments were performed to verify the utilization. Two Bearings were installed at the vacuum chamber, one was assembled with Labyrinth seal and the other was stand alone. After executing the vacuum test, it was found to be the stand alone bearing had lost more weight than the one that was assembled with the labyrinth seal. In this result, it is verified that the Labyrinth seal has useful function to preserve the lubricant that affects to the life-cycle of the Bearing.

• Journal of the Korean Ceramic Society
• /
• v.49 no.6
• /
• pp.620-624
• /
• 2012

The role of moisture remaining inside the deposition chamber during the formation of the cubic boron nitride (c-BN) phase in BN film was investigated. BN films were deposited by an unbalanced magnetron sputtering (UBM) method. Single-crystal (001) Si wafers were used as substrates. A hexagonal boron nitride (h-BN) target was used as a sputter target which was connected to a 13.56 MHz radiofrequency electric power source at 400 W. The substrate was biased at -60 V using a 200 kHz high-frequency power supply. The deposition pressure was 0.27 Pa with a flow of Ar 18 sccm - $N_2$ 2 sccm mixed gas. The inside of the deposition chamber was maintained at a moisture level of 65% during the initial stage. The effects of the evacuation time, duration time of heating the substrate holder at $250^{\circ}C$ as well as the plasma treatment on the inside chamber wall on the formation of c-BN were studied. The effects of heating as well as the plasma treatment very effectively eliminated the moisture adsorbed on the chamber wall. A pre-deposition condition for the stable and repeatable deposition of c-BN is suggested.