• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.878-880
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• 1998

Quartz crystal in contact with viscoelastic medium is described directly in terms of the electrical equivalent circuit of the system. Stearic acid is used as viscoelastic medium and deposited on the surface of quartz crystal using the Langmuir-Blodgett(LB) method. Impedance properties of quartz crystal coated with LB films which were investigated and the possibility of applying the technique to chemical sensing introduced.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.21.1-21.1
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• 2011

Controlling the morphology of a metal nanocrystal is critical to modern materials chemistry because its physical and chemical properties can be easily and widely tuned by tailoring the size and shape. Combined with ease of synthesis and processing, metal nanocrystals with desired morphologies and thus properties are promising candidates for a wide variety of applications in catalysis, sensing, imaging, electronics, and photonics, and medicine. In this talk, I would like to introduce my recent research results on the shape-controlled synthesis of metal nanocrystals using a simple aqueous method. This water-based system provides a number of merits such as simplicity, convenience, and the potential for large-scale production and enables us to synthesize metal nanocrystals with a rich variety of shapes such as truncated octahedron, cubes, bars, octahedrons, and thin plates. The ability to control the shape of metal nanocrystals provides a great opportunity to systematically investigate their catalytic and optical properties.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.245-245
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• 2006

Recent studies of single wall carbon nanotube (SWNT)/polyimide nanocomposites indicate that these materials have a potential to provide the combination of structural integrity and sensing/actuation capability. This study shows the effect of the SWNT type and concentration on the dipole orientation and piezoelectric properties of the electroactive polymide nanocomposites using a thermally stimulated current (TSC) spectroscopy. These nanocomposites exhibit very thermally stable piezoelectric properties up to $150^{\circ}C$. This presentation will highlight the dipole orientation and electroactive characteristics of the SWNT/polyimide nanocomposites and discuss their potential multifunctional aerospace applications.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.247-247
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• 2006

Chemical and physical synthesis routes were combined to prepare macroporous thin films of semiconducting metal-oxides such as $CaCu_{3}Ti_{4}O_{12}\;and\;TiO_{2}$ by sputtering onto (PMMA) microsphere templated substrates. Subsequently, the colloidal templates were removed by thermal decomposition. The remaining inorganic films comprised a monolayer of hollow hemispheres with diameter commensurate with that of the microspheres. This unique morphology increases the surface area and reduces the interfacial area between film and substrate. Consequently, the surface activity is markedly enhanced while deleterious interfacial effects between film and substrate are significantly reduced. Both effects are highly advantageous for gas sensing applications.

• Journal of the Optical Society of Korea
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• 제18권6호
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• pp.788-792
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• 2014

It has been a critical issue to reduce the size of spectrometers in many fields such as on-chip chemical and biological sensing. The proposed plasmonic channel-waveguide with a sub-micrometer width has a cutoff frequency which enables us to control wavelength dependent propagation properties. We focused on the capability of the waveguide for spectral-to-spatial mapping when the waveguide width changes gradually. In this paper, we propose a plasmonic tapered channel-waveguide structure as a compact spectrometer with a physical size of $0.24{\times}2.0{\times}0.20{\mu}m^3$. The scattering point just above the tapered waveguide moves linearly depending on the wavelength of the injecting light. The spectral-to-spatial mapping can be improved by increasing the tapered length.

• Carbon letters
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• 제14권4호
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• pp.206-209
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• 2013

Nanocomposites comprised of graphene oxide (GO) nanosheets and magnesium oxide (MgO) nanoparticles were synthesized by a sol-gel process. The synthesized samples were studied by X-ray powder diffraction, atomic force microscopy, transmission electron microscopy, and energy-dispersive X-ray analysis. The results show that the MgO nanoparticles, with an average diameter of 70 nm, are decorated uniformly on the surface of the GOs. By controlling the concentration of the MgO precursors and reaction cycles, it was possible to control the loading density and the size of the resulting MgO particles. Because the MgO particles are robustly anchored on the GO structure, the MgO/GOs nanocomposites will have future applications in the fields of adsorption and chemical sensing.

• Transactions on Electrical and Electronic Materials
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• 제8권1호
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• pp.11-14
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• 2007

Consumables used in Chemical Mechanical Polishing (CMP) have been played important role to improve quality and productivity. Since the properties of consumables constantly change with various reasons, such as shelf time, manufactured time, lot to lot variation from supplier and so on, CMP results are not constant during the process. Also, CMP process results are affected by multiple sources from wafer, conditioner, pad and slurry. Therefore, multiple sensing systems are required to monitor CMP process variation. In this paper, the authors focus on development of monitoring system for CMP process which consist of force, temperature and displacement sensor to measure the signal from CMP process. With monitoring systems mentioned above, complex CMP phenomena can be investigated more clearly.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.223-227
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• 2003

A new flexible electronic packaging technology and its medical applications are presented. Conventional silicon chips and electronic modules can be considered as "mechanically rigid box." which does not bend due to external forces. This mechanically rigid characteristic prohibits its applications to wearable systems or bio-implantable devices. Using current MEMS (Microelectromechanical Systems) technology. a surface micromachined flexible polysilicon sensor array and flexible electrode array fer neural interface were fabricated. A chemical thinning technique has been developed to realize flexible silicon chip. To combine these techniques will result in a realization of truly flexible sensing modules. which are suitable for many medical applications.

• 한국정밀공학회지
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• 제29권11호
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• pp.1159-1163
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• 2012

In this paper, we would like to introduce two dimensional non-contact position sensor by using an electromagnetic induction based coil system and an algorithm to estimate the position of pointer. The sensor which will introduce in this paper is composed of a pointer including LC resonant circuit and a sensor board to detect the electromagnetic signal from the pointer. Because of the simplicity shape of the line antenna, low cost and free form curved shape of the sensor device is possible. In this research, we proposed a new two dimensional non-contact type electromagnetic sensor system and realized the proposed sensor device. From the experiments, the proposed device can be employed for the two dimensional position sensor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.609-611
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• 1997

Pt thin films flow sensors were fabricated by using aluminum oxide films as medium layer and their characteristics were investigated after annealing at $600^{\circ}C$ for 60min. Aluminum oxide improved adhesion of Pt thin films to $SiO_2$ layer without any chemical reactions to Pt thin films under high annealing temperatures. Output voltages increased as gas flow rate and gas conductivity increased because heat loss of heater, which was integrated with a sensing resistor in the flow sensor, increased. Output voltage of flow sensor fabricated on membrane structure was 101mV at $O_2$ flow rate of 2000sccm, heating power of 0.8W while flow sensor fabricated on Si substrate without membrane had output voltage of 78mV under the same conditions.