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Your search keyword '"Oh, Sang-Hyun"' showing total 162 results
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162 results on '"Oh, Sang-Hyun"'

19. Nanoscale tweezers for single-cell biopsies

Author

Nadappuram, Binoy Paulose, Cadinu, Paolo, Barik, Avijit, Ainscough, Alexander J., Devine, Michael J., Kang, Minkyung, Gonzalez-Garcia, Jorge, Kittler, Josef T., Willison, Keith R., Vilar, Ramon, Actis, Paolo, Wojciak-Stothard, Beata, Oh, Sang-Hyun, Ivanov, Aleksandar P., and Edel, Joshua B.

Published
2019
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26. Promises and challenges of nanoplasmonic devices for refractometric biosensing

Author

Dahlin Andreas B., Wittenberg Nathan J., Höök Fredrik, and Oh Sang-Hyun

Subjects
optical biosensors, refractometric sensors, surface plasmon resonance, plasmonics, figure of merit, single molecule detection, enzyme-linked biosensing, site-specific chemistry, supported lipid bilayer, pore-spanning lipid membrane, nanoparticle, nanohole, optofluidics, Physics, QC1-999
Abstract

Optical biosensors based on surface plasmon resonance (SPR) in metallic thin films are currently standard tools for measuring molecular binding kinetics and affinities – an important task for biophysical studies and pharmaceutical development. Motivated by recent progress in the design and fabrication of metallic nanostructures, such as nanoparticles or nanoholes of various shapes, researchers have been pursuing a new generation of biosensors harnessing tailored plasmonic effects in these engineered nanostructures. Nanoplasmonic devices, while demanding nanofabrication, offer tunability with respect to sensor dimension and physical properties, thereby enabling novel biological interfacing opportunities and extreme miniaturization. Here we provide an integrated overview of refractometric biosensing with nanoplasmonic devices and highlight some recent examples of nanoplasmonic sensors capable of unique functions that are difficult to accomplish with conventional SPR. For example, since the local field strength and spatial distribution can be readily tuned by varying the shape and arrangement of nanostructures, biomolecular interactions can be controlled to occur in regions of high field strength. This may improve signal-to-noise and also enable sensing a small number of molecules. Furthermore, the nanoscale plasmonic sensor elements may, in combination with nanofabrication and materials-selective surface-modifications, make it possible to merge affinity biosensing with nanofluidic liquid handling.

Published
2013
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35. Plasmonic nanoholes in a multichannel microarray format for parallel kinetic assays and differential sensing

Author

Im, Hyungsoon, Lesuffleur, Antoine, Lindquist, Nathan C., and Oh, Sang-Hyun

Subjects
Plasmons (Physics) -- Properties, Nanotechnology -- Research, Microfluidics -- Research, Fluidic devices -- Properties, Molecular dynamics -- Research, Resonance -- Research, Protein microarrays -- Properties, Biosensors -- Design and construction, Biosensors -- Properties, Chemistry
Abstract

We present nanohole arrays in a gold film integrated with a six-channel microfluidic chip for parallel measurements of molecular binding kinetics. Surface plasmon resonance effects in the nanohole arrays enable real-time, label-free measurements of molecular binding events in each channel, while adjacent negative reference channels can record measurement artifacts such as bulk solution index changes, temperature variations, or changing light absorption in the liquid. With the use of this platform, streptavidin--biotin specific binding kinetics are measured at various concentrations with negative controls. A high-density microarray of 252 biosensing pixels is also demonstrated with a packing density of 106 sensing elements/[cm.sup.2], which can potentially be coupled with a massively parallel array of microfluidic channels for protein microarray applications.

Published
2009

36. Attenuation mechanism effect on filter shape in channelized dynamic spectral equalizers

Author

Oh, Sang-Hyun and Marom, Dan M.

Subjects
Optics, Astronomy, Physics
Abstract

Free-space-based channelized dynamic spectral equalizers are theoretically investigated by solving the temporal-frequency-dependent power-coupling integral for commonly used active device technologies: liquid-crystal modulators, tilting micromirror arrays, and deformable gratings. Channel-filter characteristics, such as bandwidth and interchannel transition, are found to depend on the different attenuation mechanisms provided by the active devices. Such information is required for choosing the proper device parameters in designing channel equalizers and similar free-space spatially dispersed subsystems. OCIS codes: 060.2340, 070.6110, 230.6120, 010.1080, 120.2440.

Published
2004

37. Monolithic fringe-field-activated crystalline silicon tilting-mirror devices

Author

Greywall, Dennis S., Pai, Chien-Shing, Oh, Sang-Hyun, Chang, Chorng-Ping, Marom, Dan M., Busch, Paul A., Cirelli, Raymond A., Taylor, Ashley J., Klemens, Fred P., Sorsch, Thomas W., Bower, John Eric, Lai, Warren Y.-C., and Soh, Hyongsok T.

Subjects
Microelectromechanical systems -- Research, Engineering and manufacturing industries, Science and technology
Abstract

A new approach is presented for fabricating monolithic crystalline silicon tilting-mirror microoptoelectromechanical systems (MOEMS) devices. The activation electrodes, etched from a thick silicon layer deposited over insulating oxide onto the top surface of a silicon-on-insulator (SOI) wafer, are displaced from the mirrors and interact with these tilting elements via electrostatic fringing fields. In contrast to the more usual parallel-plate activation, the rotation angle saturates at high voltages. This paper discusses concept, design, and processing, and also compares modeling and measured performance of a specific 9[degrees] tilt range device array. [977] Index Terms--MEMS, MOEMS, micromachined structures, optical telecommunications.

Published
2003

45. Sensitivity of resonance frequency in the detection of thin layer using nano-slit structures.

Author

Lin, Junshan, Oh, Sang-Hyun, and Zhang, Hai

Subjects
*DIELECTRIC thin films, *RESONANCE
Abstract

We derive the formulas for the resonance frequencies and their sensitivity when the nano-slit structures are used in the detection of thin layers. For a thin layer with a thickness of |$H$| deposited over the nanostructure, we show quantitatively that for both single and periodic slit structures with slit aperture size |$\delta $|⁠ , the sensitivity of resonance frequency reduces as |$H$| increases. Specifically, the sensitivity is of order |$O(\delta /H)$| if |$H>\delta $| and of order |$O(1+\ln H/\delta)$| otherwise. The evanescent wave modes are present along the interface between the thin dielectric film and ambient medium above. From the mathematical derivations, it is observed that the sensitivity of the resonance frequency highly depends on the effect of evanescent wave modes on the tiny slit apertures. [ABSTRACT FROM AUTHOR]

Published
2021
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48. Stress effects of the inter-level dielectric layer on the ferroelectric performance of integrated SrBi[sub 2]Ta[sub 2]O[sub 9] capacitors.

Author

Hong, Suk-Kyoung, Yang, B., Oh, Sang Hyun, Kang, Young Min, Kang, Nam Soo, Hwang, Cheol Seong, and Kwon, Oh Seong

Subjects
THERMAL stresses, DIELECTRICS, FERROELECTRIC crystals
Abstract

The thermal stress effects of the inter-level dielectric (ILD) layer on the ferroelectric performance of integrated Pt/SrBi[sub 2]Ta[sub 2]O[sub 9](SBT)/Pt capacitors were investigated. Two different thin film materials, pure SiO[sub 2] grown at 650 °C and B- and P-doped SiO[sub 2] grown at 400 °C by chemical vapor deposition techniques, were tested as an ILD layer. The ILD layer encapsulated the SBT capacitor array. During high temperature thermal cycling (up to 800 °C) after ILD deposition, which is used for both densifying the ILD and curing of the various damage imposed on the SBT capacitors, a large thermal stress occurred in the bottom Pt layer due to the thermal expansion mismatch between the various layers. In particular, the pure SiO[sub 2] ILD layer between the capacitors did not allow thermal expansion of the Pt layers, which led to a large accumulation of compressive stress in the layer. This resulted in hillock formation in the bottom Pt layer and eventual capacitor failure. However, the B- and P-doped SiO[sub 2] ILD layer contracted during thermal cycling by removing residual impurities, which allowed greater expansion of the Pt layer. Therefore, compressive stress accumulation did not occur and excellent ferroelectric properties were thus obtained from the integrated capacitor array. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2001
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