Browsing by Author "Tseng, Fan-Gang"

Now showing 1 - 12 of 12

A Simple Fiber Bragg Grating-Based Sensor Network Architecture with Self-Protecting and Monitoring Functions
(2011-02-01)
Yeh, Chien-Hung
;
Chow, Chi-Wai
;
Wu, Ping-Chun
;
Tseng, Fan-Gang
;
光電工程學系
A novel fiber Bragg grating (FBG)-based passive sensor architecture, which can be used to protect the fiber cut and monitor the multiple sensors simultaneously, is proposed and experimentally demonstrated. Here, we employ a wavelength-tunable erbium-doped fiber (EDF) laser scheme with 25 km cavity length acting as the detecting light source in central office (CO). Each FBG sensor, serving as a feedback element, is used in proposed sensor architecture. By tuning the tunable bandpass filter (TBF) placing inside cavity to match the corresponding Bragg wavelength of FBG over the amplification bandwidth, we can retrieve the related wavelength lasing for the FBG sensing and monitoring simultaneously. Moreover, the survivability and capacity of the passive FBG sensor architecture can be also enhanced.
Design and Fabrication of a Small-Form-Factor Optical Pickup Head
(2009-05-01)
Chiu, Yi
;
Shih, Hsi-Fu
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Chiou, Jin-Chern
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Cheng, Shih-Tung
;
Hung, Kuo-Yung
This paper presents the design and fabrication of a small-form-factor optical pickup head (OPH) for both red and blue wavelength. A holographic optical element (HOE) is used for beam splitting, aberration correction, and servo-signal generation to reduce the number of components and simplify the assembly procedure. In addition to demonstrating this OPH by using existing discrete components, several key components and processes are developed to use micro-electro-mechanical system (MEMS) technology to facilitate batch fabrication and wafer level assembly of the micro OPU.
Formation of suspended bilayer lipid membrane between electrowetting-driven encapsulated droplets
(2014-09-01)
Fan, Shih-Kang
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Chen, Ching-Wen
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Lin, Yi-Ying
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Chen, Li-Chi
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Tseng, Fan-Gang
Using limited lipid molecules held by two water-core/oil-shell encapsulated droplets, we formed an optically observable bilayer lipid membrane (BLM) across a microfabricated aperture whose dimension was precisely determined and easily scalable. For the minute volume of a 0.1 mu L oil (n-decane) shell encapsulating a 1.5 mu L water core droplet, only 0.2 to 2.8 nmol or 0.17 to 2.4 mu g lipid was required. Microscopes and electrophysiological measurements were performed on the parallel-plate device with three major steps demonstrated: (1) manipulating self-assembled lipid monolayers at the water-oil interface of the encapsulated droplets by electrowetting-on-dielectric (EWOD), (2) forming a BLM by bringing two lipid monolayers towards the aperture and thinning down the oil film between them by Young-Laplace pressure, and (3) incorporating membrane-bound nanopores, alpha-hemolysin (alpha HL), on the BLM. This study shows the influence of the lipid concentration to the interfacial tension and EWOD. Plateau-Gibbs border and black membrane area of the BLM were optically observed, while trans-membrane electrophysiological signals were electrically recorded from a pair of Ag/AgCl electrodes. (C) 2014 AIP Publishing LLC.
Immersion Lithography Apparatus and Tank Thereof
(2010-04-08)
Hung, Kuo-Yung
;
Tseng, Fan-Gang
A tank for an immersion lithography apparatus provided. The tank has a container with a bottom plate and side plates connected to each, wherein the side plates surround and connect all edges of the bottom plate. The container is filled in at least a liquid having a refractive index thereof from about 1.4 to about 1.8. A platform is located in the container and immersed in the liquid. The platform has an axle fastened on a side thereof parallel to the bottom plate, wherein the axle passes through a bearing hole penetrated through one of the side plates. A roller disposed outside the container connects to the axle to rotate the axle, and furthermore, to incline the platform accordingly.
In-situ Formation and Assembly of Gold Nanoparticles by Gum Arabic as Efficient Photothermal Agent for Killing Cancer Cells
(2013-10-01)
Liu, Ching-Ping
;
Lin, Fong-Sian
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Chien, Chih-Te
;
Tseng, Sheng-Yang
;
Luo, Chih-Wei
Measurement of Organic Chemical Refractive Indexes Using an Optical Time-Domain Reflectometer
(2012-01-01)
Yeh, Chien-Hung
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Chow, Chi-Wai
;
Sung, Jiun-Yu
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Wu, Ping-Chun
;
Whang, Wha-Tzong
In this investigation, we propose and experimentally demonstrate a method for measuring the refractive index (RI) of liquid organic chemicals. The scheme is based on a single-mode fiber (SMF) sensor and an optical time-domain reflectometer (OTDR). Here, due to the different reflectance (R) between the SMF and organic liquid chemicals, the reflected power level of the backscattering light (BSL) measured by the OTDR would be different. Therefore, we can measure the RI of chemical under test via the measured BSL level. The proposed RI sensor is simple and easy to manipulate, with stable detected signals, and has the potential to be a valuable tool for use in biological and chemical applications.
Optimum electrostatic force control for fabricating a hybrid UV-curable aspheric lens
(2010-07-01)
Hung, Kuo-Yung
;
Chang, Liang-Wei
;
Tseng, Fan-Gang
;
Chiou, Jin-Chern
;
Chiu, Yi
The purpose of this paper is to use a hybrid structure and the electrostatic force to fabricate aspheric lenses with high optical transmittance (95% at 405 nm). The hybrid structure is composed of Norland Optical Adhesive 63 (NOA63) (refractive index: 1.5802 at 405 nm) and BK-7 glass (refractive index: 1.5302). OSLO (Optics Software for Layout and Optimization) and CFD (Computational Fluid Dynamics) software packages were used to simulate the electric field gradient between the top and bottom electrodes and to produce the optimum bottom electrode design. Different electrode designs were also tested in order to optimize the morphology of the lens profile. The resulting lens profiles have clear apertures of approximately 0.92 mm with maximum shape errors of less than 0.18% and the spot size of the fabricated aspheric lenses can be controlled to approximately 0.504 mu m. This technology can be used as a generic approach to fabricate lenses for applications in various micro-optical systems.
Pore-Spanning Lipid Membrane under Indentation by a Probe Tip: A Molecular Dynamics Simulation Study
(2011-10-04)
Huang, Chen-Hsi
;
Hsiao, Pai-Yi
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Tseng, Fan-Gang
;
Fan, Shih-Kang
;
Fu, Chien-Chung
We study the indentation of a free-standing lipid membrane suspended over a nanopore on a hydrophobic substrate by means of molecular dynamics simulations. We find that in the course of indentation the membrane bends at the point of contact and the fringes of the membrane glide downward intermittently along the pore edges and stop gliding when the fringes reach the edge bottoms. The bending continues afterward, and the large strain eventually induces a phase transition in the membrane, transformed from a bilayered structure to an interdigitated structure. The membrane is finally ruptured when the indentation goes deep enough. Several local physical quantities in the pore regions are calculated, which include the tilt angle of lipid molecules, the nematic order, the included angle, and the distance between neighboring lipids. The variations of the;e quantities reveal many detailed, not-yet-specified local structural transitions of lipid molecules under indentation. The force indentation curve is also studied and discussed. The results make a connection between the microscopic structure and the macroscopic properties and provide deep insight into the understanding of the stability of a lipid membrane spanning over nanopore.
Simple and Fast Method To Fabricate Single-Nanoparticle-Terminated Atomic Force Microscope Tips
(2013-06-27)
Cheng, Hui-Wen
;
Chang, Yuan-Chih
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Yuan, Chi-Tsu
;
Tang, Song-Nien
;
Chang, Chia-Seng
This paper introduces a simple, yet controllable scheme to pick up a single 13 nm Au nanoparticle (Au-NP) using the tip of an atomic force microscope (AFM) probe through the application of electrical biases between the tip and the Au-NP. Transmission electron microscope (TEM) images were acquired to verify that a single Au-NP was attached to the AFM probe. We postulate that the mechanism underlying the ability to manipulate individual Au-NPs at the apex of the AFM probe tip is Coulomb interaction induced by tip bias. The AFM tip with the attached Au-NP was then used to study the interaction between a single quantum dot (QD) and the Au-NP. The blinking behavior of single colloidal CdSe/ZnS core/shell QD was significantly suppressed with the approach of the 13 nm Au-NP attached to the AFM tip.
Single Molecule Take-and-Place Technique for Positioning a Membrane Protein on a Lipid Bilayer
(2015-09-10)
Liu, Tseng-Huang
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Huang, Yun-Tzu
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Cheng, Hui-Wen
;
Chen, Yen-Wei
;
Lee, Ching-Hung
Manipulating a single protein molecule on liposomes or planar lipid bilayers is a useful technique for studying membrane-bound proteins, receptors, or ion transporters and for delicate applications including biosensor chips, drug screening, and clinical diagnoses. However, several key breakthroughs are required for success through difficult techniques such as single protein take-and-place with reasonable spatiotemporal control. In this report, a novel method was established for placing a single transmembrane protein onto a patterned lipid bilayer. A surface-functionalized 1.8 nm gold nanoparticle was first engineered at the tip of an atomic force microscope. A single transmembrane protein, H+-translocating pyrophosphatase with six-histidine residues tag, was then picked up using such a microscopy tip where its nanoparticle was modified by nickel-nitrilotriacetic acid. Two-step fluorescence bleaching observation and quantum dot blinking analysis subsequently verified successful manipulation of a single functional protein on a lipid membrane in a predetermined manner. Furthermore, the enzymatic activity from the single H+-translocating pyrophosphatase was determined, demonstrating that membrane proteins retain their functions on the lipid bilayer through a single-molecule take-and-place technique. This innovative technique overcomes current limitations and provides a single biomolecule nanomanipulation system for versatile studies of membrane-bound proteins.
The proximity between C-termini of dimeric vacuolar H(+)-pyrophosphatase determined using atomic force microscopy and a gold nanoparticle technique
(2009-08-01)
Liu, Tseng-Huang
;
Hsu, Shen-Hsing
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Huang, Yun-Tzu
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Lin, Shih-Ming
;
Huang, Tsu-Wei
Vacuolar H(+)-translocating inorganic pyrophosphatase [vacuolar H(+)-pyrophosphatase (V-PPase); EC 3.6.1.1] is a homodimeric proton translocase; it plays a pivotal role in electrogenic translocation of protons from the cytosol to the vacuolar lumen, at the expense of PP(i) hydrolysis, for the storage of ions, sugars, and other metabolites. Dimerization of V-PPase is necessary for full proton translocation function, although the structural details of V-PPase within the vacuolar membrane remain uncertain. The C-terminus presumably plays a crucial role in sustaining enzymatic and proton-translocating reactions. We used atomic force microscopy to visualize V-PPases embedded in an artificial lipid bilayer under physiological conditions. V-PPases were randomly distributed in reconstituted lipid bilayers; approximately 43.3% of the V-PPase protrusions faced the cytosol, and 56.7% faced the vacuolar lumen. The mean height and width of the cytosolic V-PPase protrusions were 2.8 +/- 0.3 nm and 26.3 +/- 4.7 nm, whereas those of the luminal protrusions were 1.2 +/- 0.1 nm and 21.7 +/- 3.6 nm, respectively. Moreover, both C-termini of dimeric subunits of V-PPase are on the same side of the membrane, and they are close to each other, as visualized with antibody and gold nanoparticles against 6xHis tags on C-terminal ends of the enzyme. The distance between the V-PPase C-terminal ends was determined to be approximately 2.2 +/- 1.4 nm. Thus, our study is the first to provide structural details of a membrane-bound V-PPase dimer, revealing its adjacent C-termini.
The proximity between C-termini of dimeric vacuolar H+-pyrophosphatase determined using atomic force microscopy and a gold nanoparticle technique
(2009-08-01)
Liu, Tseng-Huang
;
Hsu, Shen-Hsing
;
Huang, Yun-Tzu
;
Lin, Shih-Ming
;
Huang, Tsu-Wei
Vacuolar H+-translocating inorganic pyrophosphatase [vacuolar H+-pyrophosphatase (V-PPase); EC 3.6.1.1] is a homodimeric proton translocase; it plays a pivotal role in electrogenic translocation of protons from the cytosol to the vacuolar lumen, at the expense of PPi hydrolysis, for the storage of ions, sugars, and other metabolites. Dimerization of V-PPase is necessary for full proton translocation function, although the structural details of V-PPase within the vacuolar membrane remain uncertain. The C-terminus presumably plays a crucial role in sustaining enzymatic and proton-translocating reactions. We used atomic force microscopy to visualize V-PPases embedded in an artificial lipid bilayer under physiological conditions. V-PPases were randomly distributed in reconstituted lipid bilayers; approximately 43.3% of the V-PPase protrusions faced the cytosol, and 56.7% faced the vacuolar lumen. The mean height and width of the cytosolic V-PPase protrusions were 2.8 +/- 0.3 nm and 26.3 +/- 4.7 nm, whereas those of the luminal protrusions were 1.2 +/- 0.1 nm and 21.7 +/- 3.6 nm, respectively. Moreover, both C-termini of dimeric subunits of V-PPase are on the same side of the membrane, and they are close to each other, as visualized with antibody and gold nanoparticles against 6xHis tags on C-terminal ends of the enzyme. The distance between the V-PPase C-terminal ends was determined to be approximately 2.2 +/- 1.4 nm. Thus, our study is the first to provide structural details of a membrane-bound V-PPase dimer, revealing its adjacent C-termini.