• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.258-261
• /
• 2009

In this work we present a process to fabricate lowtemperature polysilicon (LTPS) TFTs on polyimide (PI) layers, spin-coated on Si-wafer used as rigid carrier. This process has been then used to fabricate elementary circuits as well as circuits for sensor applications.

• Electrical & Electronic Materials
• /
• v.6 no.4
• /
• pp.290-301
• /
• 1993

최근 전기전자재료 분야에서 유기재료의 초박막화 기술이 주목되고 있다. 유기재료는 구성하는 유기분자에 여러가지 기능을 부여할 수 있기 때문에 무기재료 이상의 기능 또는 무기재료에서는 나타나지 않던 새로운 기능의 발현이 가능하기 때문에 오늘날 관심의 대상이 되고 있다. 이와같이 분자자체가 가지고 있는 기능을 추구하여 가면 궁극적으로는 분자소자의 제안에서처럼 분자를 1개씩 단위로 하여 조립하여 희망의 소자를 구축하는 것이 가능할 것이다. 그러나 현실적으로 우리들 주변에 있는 기술로서 이와같은 분자소자를 실현한다는 것은 아직 시기상조이지만 집합체로서 유기분자를 활용하거나 분자가 가진 기능을 효율 좋게 이용할 수 있다면 현시점에서도 가능할 것으로 생각된다. 따라서 이를 위한 구체적인 방법으로서 박막화가 생각되었으며 그 수단으로서 유기초박막제작기술이 있다.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.3 no.1
• /
• pp.19-23
• /
• 1998

We enhanced the sensitivity of surface plasmon resonance biosensor by the conversion of the real-time direct binding immunoassay into the sandwich immunoassay, in which colloidal gold particles coated with anti-mouse IgG was used. By the immobilization of anti-mouse IgG onto the carboxymethyl dextran surface of thin gold film, the direct binding of analyte(mouse IgG) onto the sensor chip, and the injection of colloidal gold particles coated with anti-mouse IgG, about 100 times of sensitivity enhancement was obtained. This result suggests that nanoparticles, which has a high refractive index, homogeneous ultrafine structure and capability of size control, would be applicable for the detection of very small quantity of biomaterial.

• Journal of Industrial and Engineering Chemistry
• /
• v.68
• /
• pp.393-398
• /
• 2018

This work offers a promising approach for development of a temperature-responsive colorimetric display platform. For this purpose, uniform thermochromic microcapsules consisting of a cholesteric liquid crystal (CLC) core and a thin polyurethane shell layer were fabricated by conducting in-situ condensation polymerization at the interface of monodisperse CLC-in-water emulsion drops. Colloidal packing-driven microcapsule registry led to exact 2-dimensional positioning of CLC microcapsules into a holes-patterned flexible film stencil. Furthermore, we showed that the designated registry of different color types of CLC microcapsules on the stencil enabled development of a microwriting display technology capable of reversible text representation according to temperature change.

• Current Optics and Photonics
• /
• v.4 no.4
• /
• pp.345-352
• /
• 2020

We describe a calibration method to improve the accuracy of interferometric snapshot spectroscopic ellipsometry employing a dual-spectrometer sensor scheme. Conventional spectral wavelength calibration of a spectrometer has been performed by using a calibration lamp having multiple peaks at specific wavelength. This paper shows that such a conventional spectrometer calibration method is inappropriate for the proposed interferometric snapshot spectroscopic ellipsometry to obtain highly accurate ellipsometric phase information. And also, systematic error analysis of interferometric snapshot spectroscopic ellipsometry is conducted experimentally.

• Journal of Sensor Science and Technology
• /
• v.30 no.5
• /
• pp.273-278
• /
• 2021

Here, we studied the change in the mechanical stiffness of a diaphragm according to the corrugation pattern. The diaphragm consists of a silicon oxide and nitride double layer; a corrugation pattern was formed by dry etching, and the diaphragm was released by wet etching. The fabrication of the thin film was verified using focused ion beam and scanning electron microscopy images. The mechanical stiffness of the diaphragm was obtained by measuring the surface vibration using a laser Doppler vibrometer while applying external sound pressure. Flat squares, diaphragms with square corrugations, and circular corrugation patterns were measured and compared. The stiffness of the diaphragm with a corrugation structure was found to be smaller than that without a corrugation structure; in particular, circular corrugation showed a better effect because of the high symmetry. Furthermore, the effect of corrugation was theoretically predicted. The proposed corrugated diaphragm showed comparable flexibility with the state-of-the-art MEMS microphone diaphragm.

• Journal of Sensor Science and Technology
• /
• v.30 no.1
• /
• pp.10-14
• /
• 2021

Wet etching is more economical than dry etching and provides a uniform etching depth regardless of wafer sizes. Typically, potassium hydroxide (KOH) and tetra-methyl-ammonium hydroxide (TMAH) solutions are widely used for the wet etching of silicon. However, there is a limit to the wet etching process when a material deposited on an unetched surface reacts with an etching solution. To solve this problem, in this study, an apparatus was designed and manufactured to physically block the inflow of etchants on the surface using a rubber O-ring. The proposed apparatus includes a heater and a temperature controller to maintain a constant temperature during etching, and the hydrostatic pressure of the etchant is considered for the thin film structure. A corrugation membrane with a diameter of 800 ㎛, thickness of 600 nm, and corrugation depth of 3 ㎛ with two corrugations was successfully fabricated using the prepared device.

• Journal of Sensor Science and Technology
• /
• v.30 no.2
• /
• pp.71-75
• /
• 2021

Recently, transition-metal-based hydroxide materials have attracted significant attention in various electrochemical applications owing to their low cost, high stability, and versatility in composition and morphology. Among these applications, transition-metal-based hydroxides have exhibited significant potential in supercapacitors owing to their multiple redox states that can considerably enhance the supercapacitance performance. In this study, nanostructured Ni-Mn double hydroxide is directly grown on a conductive substrate using an electrodeposition method. Ni-Mn double hydroxide exhibits excellent electrochemical charge-storage properties in a 1 M KOH electrolyte, such as a specific capacitance of 1364 Fg-1 at a current density of 1 mAcm-2 and a capacitance retention of 94% over 3000 charge-discharge cycles at a current density of 10 mAcm-2. The present work demonstrates a scalable, time-saving, and cost-effective approach for the preparation of Ni-Mn double hydroxide with potential application in high-charge-storage kinetics, which can also be extended for other transition-metal-based double hydroxides.

• Journal of Ceramic Processing Research
• /
• v.13 no.spc2
• /
• pp.359-362
• /
• 2012

We have employed Kelvin force microscopy (KFM) system to measure the potential change of a single SnO2 nanowire which had been synthesized on the Au thin film by a thermal process. By using the KFM probing technique, Rh coated conducting cantilever can approach a single SnO2 nanowire in nano scale and get the potential images with oscillating AC bias between Au electrode and cantilever. Also, during imaging the potential status, we controlled the concentration of oxygen in measuring chamber to change the ionosorption rate. From the results of such experiments, we verified that the surface potential as well as doping type of a single SnO2 nanowire could be changed by oxygen ionosorption.

• Journal of Sensor Science and Technology
• /
• v.32 no.4
• /
• pp.252-256
• /
• 2023

A one-step method for nanoscale patterning of silver ionic ink on a substrate is developed using a microscale, elastic mold deformation. This method yields unique micro/nanoscale metallic structures that differ from those produced using the original molds. The linewidth of these metallic structures is significantly reduced (approximately 10 times) through the sidewall deformation of the original mold cavity on a thin liquid film, as verified by finite element analysis. The process facilitates the fabrication of various, isolated and complex micro/nanoscale metallic structures with negligible residual layers at low cost and high throughput. These structures can be utilized for various applications, including optoelectronics, wearable sensors, and metaverse-related devices. Our approach offers a promising tool for manipulation and fabrication of micro/nanoscale structures of various functional materials.