Browsing by Author "Hsu, Ray-Quen"

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Analysis for diving regulator applying local heating mechanism of vapor chamber in insert molding process
(2011-02-01)
Wang, Jung-Chang
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Li, Ai-Tsung
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Tsai, Yu-Pin
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Hsu, Ray-Quen
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機械工程學系
This paper aims to use the local heating mechanism, along with the excellent thermal performance of vapor chamber, to analyze and enhance the strength of products formed after insert molding process. In the insert molding process, the metal insert is firstly placed into the mold, and then formed into an embedded plastic product named diving regulator by injection molding. These results indicate that, the product formed by the local heating mechanism of vapor chamber can reduce the weld line efficiency and achieve high strength, which passed the standard of 15.82 N-m torque test, with a yield rate up to 100%. (C) 2010 Elsevier Ltd. All rights reserved.
Analysis of InAsN quantum dots by transmission electron microscopy and photoluminescence
(2008-10-01)
Hsu, Chiung-Chih
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Hsu, Ray-Quen
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Wu, Yue-Han
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Chi, Tung-Wei
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Chiang, Chen-Hao
Quantum dots (QDs) have great potential in optical fiber communication applications were widely recognized. The structure of molecular beam epitaxy (MBE) grew InAsN QDs were investigated by transmission electron microscopy (TEM) and measured their optical properties by photoluminescence (PL). TEM images show that the InAsN QDs are irregular or oval shaped. Some of the InAsN QDs are observed to have defects, such as dislocations at or near the surface in contrast to InAs QDs, which appear to be defect free. PL results for InAsN QDs showed a red-shifted emission peak. In addition, the InAsN emission peak is broader than InAs QDs, which supports the TEM observation that the size distribution of the InAsN QDs is more random than InAs QDs. The results show that the addition of nitrogen to InAs QDs leads to a decrease in the average size of the QDs, bring changes in the QD's shape, compositional distribution, and optical properties. (C) 2008 Published by Elsevier B.V.
Application of porous oxide layer in plastic/metal direct adhesion by injection molding
(2015-08-03)
Yeh, Ren-Yu
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Hsu, Ray-Quen
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機械工程學系
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Department of Mechanical Engineering
In this study, porous oxide layers were coated on aluminum sheets by plasma electrolytic oxidation (PEO) treatment. The PEO-treated aluminum sheets were then inserted and direct heated in the injection mold. The melting plastic penetrated and solidified in the micropores during the injection molding process, consequently achieving plastic/metal direct adhesion through micro-mechanical interlocking. The effects of the different surface morphologies of PEO coatings on plastic/metal adhesion were studied by shear test and microscopic characterizations. The microstructures were varied by changing PEO process parameters. The bonding strength was affected by the surface morphology changes, and the experimental results show that the surface porosity is a major factor in the direct adhesion. Reliable joints can be achieved on the porous coating, and the strength was proportional to the surface porosity. The shear strength in this study was in a range of approximately 3-8MPa with 7-20% surface porosity.
Chip-based protein-protein interaction studied by atomic force microscopy
(2012-10-01)
Kao, Feng-Sheng
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Ger, Waylon
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Pan, Yun-Ru
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Yu, Hui-Chen
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Hsu, Ray-Quen
In this article, a technique for accurate direct measurement of protein-to-protein interactions before and after the introduction of a drug candidate is developed using atomic force microscopy (AFM). The method is applied to known immunosuppressant drug candidate Echinacea purpurea derived cynarin. T-cell/CD28 is on-chip immobilized and B-cell/CD80 is immobilized on an AFM tip. The difference in unbinding force between these two proteins before and after the introduction of cynarin is measured. The method is described in detail including determination of the loading rates, maximum probability of bindings, and average unbinding forces. At an AFM loading rate of 1.44 x 104?pN/s, binding events were largely reduced from 61?+/- 5% to 47?+/-?6% after cynarin introduction. Similarly, maximum probability of bindings reduced from 70% to 35% with a blocking effect of about 35% for a fixed contact time of 0.5?s or greater. Furthermore, average unbinding forces were reduced from 61.4 to 38.9?pN with a blocking effect of similar to 37% as compared with similar to 9% by SPR. AFM, which can provide accurate quantitative measures, is shown to be a good method for drug screening. The method could be applied to a wider variety of drug candidates with advances in bio-chip technology and a more comprehensive AFM database of protein-to-protein interactions. Biotechnol. Bioeng. 2012; 109: 24602467. (c) 2012 Wiley Periodicals, Inc.
Development of ultrasonic direct joining of thermoplastic to laser structured metal
(2016-03-01)
Yeh, Ren-Yu
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Hsu, Ray-Quen
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機械工程學系
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Department of Mechanical Engineering
This work reports on an improved ultrasonic welding process for the direct joining of thermoplastic and metal. A metal thin plate was structured with grid arrays on a micro-scale level by laser irradiation. A thermoplastic part was placed on the structured region, and ultrasonic welding or ultrasonic hot welding was applied. The thermoplastic was locally melted and re-solidified in the structured grooves with very low energy input due to the tiny initial contact area of the grid tips. Single lap shear specimens and boss specimens were used to study the feasibility and performance of hybrids made by this joining method. Both shear strength and normal tensile strength were affected by changes in the grid structures and welding parameters, and the experimental results show that the micro-structure geometry of the metal plate is a major factor in the joining strength. Successful welds required that process cycle times be less than 1 s. Furthermore, the mold holding the metal sheet was heated in the ultrasonic hot welding experiments, and the heated mold significantly enhanced the joint quality. Ultrasonic hot welding appears to be a fast, low cost, and reliable method to produce plastic/metal hybrid products for electronics and other industrial applications. (C) 2015 Elsevier Ltd. All rights reserved.
Efficacy verification and microscopic observations of an anticancer peptide, CB1a, on single lung cancer cell
(2012-12-01)
Kao, Feng-Sheng
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Pan, Yun-Ru
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Hsu, Ray-Quen
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Chen, Hueih-Min
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機械工程學系
In this work, we introduce a new customized anti-lung cancer peptide, CB1a, with IC50 of about 25.0 +/- 1.6 mu M on NCI-H460 lung cancer cells. Using a multi-cellular tumor spheroid (MCTS) model, results show that CB1a is potent in preventing the growth of lung cancer tumor-like growths in vitro. Additionally, atomic force microscopy (AFM) was used to examine cell surface damage of a single cancer. The mechanism for cell death under CB1a toxicity was verified as being largely due to cell surface damage. Moreover, with a treatment dosage of CB1a at 25 mu M, Young's module (E) shows that the elasticity and stiffness of cancer cell decreased with time such that the interaction time for a 50% reduction of E (IT50) was about 7.0 min. This new single-cell toxicity investigation using IT50 under AFM assay can be used to separately verify drug efficacy in support of the traditional IC50 measurement in bulk solution. These results could be of special interest to researchers engaged in new drug development. (C) 2012 Elsevier B.V. All rights reserved.
Efficiency optimisation of proteins on a chip
(2015-01-01)
Wu, Wei-jen
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Huang, Hsuan-yu
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Hsu, Wei-Yeh
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Hsu, Ray-Quen
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Chen, Hueih-Min
This study elucidates that the protein reorientation on a chip can be changed by an external electric field (EEF) and optimised for achieving strong effective binding between proteins. Protein A and its binding protein immunoglobulin G (IgG) were used as an example, in addition to an anticancer peptide (CB1a) and its antibody (anti-CB1a). The binding forces (BFs) were measured by atomic force microscopy (AFM) with EEFs applied at different angles (EEF degrees). The optimal angle (OA) of the EEF (OAEEF degrees) corresponding to the maximum binding force (BFmax) was obtained. The results showed that the BFmax values between IgG/Protein A and anti-CB1a/CB1a were 6424.2 +/- 195.3 pN (OAEEF degrees = 45 degrees) and 729.1 +/- 33.2 pN (OAEEF degrees = 22.5 degrees), respectively. Without an EEF, the BF values were only 730.0 +/- 113.9 pN and 337.3 +/- 35.0 pN, respectively. Based on these observations, we concluded that the efficient optimisation of protein-protein interaction on a chip is essential. This finding is applicable to the industrial fabrication of all protein chips.
Fast incorporation of primary amine group into polylactide surface for improving C2C12 cell proliferation using nitrogen-based atmospheric-pressure plasma jets
(2014-01-01)
Yang, Yi-Wei
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Wu, Jane-Yii
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Liu, Chih-Tung
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Liao, Guo-Chun
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Huang, Hsuan-Yu
In this article, we report the development of the fast incorporation of primary amine functional groups into a polylactide (PLA) surface using the post-discharge jet region of an atmospheric-pressure nitrogen-based dielectric barrier discharge (DBD). Plasma treatments were carried out in two sequential steps: (1) nitrogen with 0.1% oxygen addition, and (2) nitrogen with 5% ammonia addition. The analyses show that the concentration of N/C ratio, surface energy, contact angle, and surface roughness of the treated PLA surface can reach 19.1%, 70.5 mJ/m(2), 38 degrees and 73.22 nm, respectively. In addition, the proposed two-step plasma treatment procedure can produce a PLA surface exhibiting almost the same C2C12 cell attachment and proliferation performance as that of the conventional gelatin coating method. Most importantly, the processing/preparation time is reduced from 13-15 h (gelatin coating method) to 5-15 min (two-step plasma treatment), which is very useful in practical applications. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 160-169, 2014.
Hot Embossing of Parallel v-Groove Microstructures on Glass
(2009-11-01)
Hsu, Ray-Quen
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Wang, Hsing-Bun
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Liang, Da-Lan
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機械工程學系
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Department of Mechanical Engineering
A series of parallel v-groove microstructures was embossed on glass at an elevated temperature. The effects of glass temperature, applied pressure, holding time, and demold temperature on the conformity between the product and the tool were studied. We found that very precise microstructures can be fabricated on glass at temperatures about 35 degrees-55 degrees C above the glass transition temperatures. However, careful attention should be paid to the demold temperature and the mold release agent in order to prevent the tool from sticking to the glass.
Improved Performance for Dye-Sensitized Solar Cells Using a Compact TiO2 Layer Grown by Sputtering
(2014)
Chang, Hung-Chih
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Twu, Ming-Jenq
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Hsu, Chun-Yao
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Hsu, Ray-Quen
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Kuo, Chin-Guo
This work determines the effect of compact TiO2 layers that are deposited onto fluorine-doped tin oxide (FTO), to improve the performance of dye-sensitized solar cells (DSSC). A series of compact TiO2 layers are prepared using radio frequency (rf) reactive magnetron sputtering. The films are characterized using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and UV-Vis spectroscopy. The results show that when the Ar/O-2/N-2 flow rates are 36 : 18 : 9, the photo-induced decomposition of methylene blue and photo-induced hydrophilicity are enhanced. After annealing at 450 degrees C in an atmosphere ambient for 30 min, the compact TiO2 layers exhibit higher optical transmittance. The XRD patterns for the TiO2 films for FTO/glass show a good crystalline structure and anatase (101) diffraction peaks, which demonstrate a higher crystallinity than the ITO/glass films. As a result of this increase in the short circuit photocurrent density, the open-circuit photovoltage, and the fill factor, the DSSC with the FTO/glass and Pt counter electrode demonstrates a solar conversion efficiency of 7.65%.
Interfacial characterization of nickel-yttria-stabilized zirconia cermet anode/interconnect joints with Ag-Pd-Ga active filler for use in solid-oxide fuel cells
(2015-01-21)
Chao, Chih-Long
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Chu, Chun-Lin
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Fuh, Yiin-Kuen
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Hsu, Ray-Quen
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Lee, Shyong
Nickel yttria-stabilized zirconia cermet anode (Ni-YSZ)/interconnect joints with silver palladium gallium (Ag-9Pd-9Ga) active fillers are prepared by vacuum brazing. The joint structure and microstructure are analyzed by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEWEDS), and by using an electron probe microanalyzer (EPMA). SEM observations of the joint show no cracks near the interface, confirming the compatibility of the Ag-9Pd-9Ga filler with a different anode and interconnect. The XRD pattern of the joint specimens oxidized at 800 degrees C for 250 h shows Cr2O3 and (Mn,Cr)(3)O-4 surface layers. EPMA analysis of the cell/Ag-9Pd-9Ga/alloys joint at the cross section shows Cr, O, Fe, Zr, Ni, Ag, Pd, Ga, Y, and Mn. Overall, the results indicate that the bonding between metal and cermet is well established and the interface is smooth. By correlating the XRD and EPMA analysis results, we also analyzed the possible stages during joint oxidation. The joint strength was evaluated at 25 and 800 degrees C under shear and tensile loading conditions, respectively, and the brazed Ag-9Pd-9Ga sealant compared favorably with the commercially available glass-ceramic GC-9 counterpart. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Joint strength of Ag-9Pd-9Ga brazed interconnect and anode-supported electrolyte for solid-oxide fuel cell applications
(2018-09-01)
Chao, Chih-Long
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Chu, Chun-Lin
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Fuh, Yiin-Kuen
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Hsu, Ray-Quen
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Lee, Shyong
A newly developed Ag-9Pd-9Ga active filler was vacuum brazed, and the mechanical properties between the metallic interconnects (SS430, Crofer22 APU, Crofer22 H) and a Ni-yttria-stabilized zirconia cermet anode were systematically investigated. The results indicate that the bonding between metal and cermet is well established and that the interface is smooth. The joint strength evaluated at both 25? and 800? under shear and tensile loading conditions confirmed that the brazed Ag-9Pd-9Ga sealant compared favorably with its commercially available glass-ceramic GC-9 counterpart.
Morphology and optical properties of single- and multi-layer InAs quantum dots
(2010-08-01)
Hsu, Chiung-Chih
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Hsu, Ray-Quen
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Wu, Yue-Han
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機械工程學系
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材料科學與工程學系
An understanding of the structural and optical properties of quantum dots (QDs) is critical for their use in optical communication devices. In this study, single- and multi-layer self-organized InAs QDs grown on (001) GaAs substrates by molecular beam epitaxy (MBE) were investigated. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images show that the lateral size of multi-layer InAs QDs are larger and flatter than single-layer InAs QDs, which are oval-shaped. The change in shape and size may be attributed to the presence of InGaAs spacer layers in multi-layer InAs QDs. Reciprocal spacer mapping and fast Fourier transformation images clearly show that InGaAs spacer layers present in the multi-layer InAs QDs structures help to release the strain originally existing in the QDs. In addition, the photoluminescence peak of the multi-layer InAs QDs is broader than QD in the single-layer one, which implies that the multi-layer InAs QDs size variation is more random than the single-layer one and this corresponds with the HAADF-STEM images. These results prove that spacer layers release strain influencing the morphology and optical properties of the QDs.
Study of an electromagnetic control swing blade blower
(2015-04-15)
Li, Ai-Tsung
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Tseng, Hsuan-Kai
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Hsu, Ray-Quen
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機械工程學系
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Department of Mechanical Engineering
Investigation of an electromagnetically controlled swing blade blower is the major objectives of this study. A fan of this type consumes low power, emits little noise and vibration, and is small in size, which makes it suitable for application in consumer electronic products. It is based on the interaction between a permanent magnet and a magnetic coil field. This drives the fan blades, increasing the volume of wind flow. Therefore, the fan design is a major factor in the wind velocity. In this study, materials, fan shape, and the resonance frequency are the design parameters considered. With proper resonance frequency and blade shape, air flow can be greatly increased. Both numerical simulations and experimental analysis were carried out in this study. ANSYS software was used in a 2D simulation to predict the flow fields and compare the results with experiments to construct a simulation system. The simulation system was used to study various blade related parameters including materials, thickness, fan shape, resonance frequency, and fan tip displacement on the airflow wind velocity, while the power consumption was maintained within 0.25 W via electromagnetic actuator. Numerical simulations and experimental results show that trimming the fan blade area causes the resonance frequency and the tip displacement to increase. Therefore, with proper fan shape, the Aluminum 1050 fan obtained the highest wind velocity, up to 1.81 m/s. In sum, the numerical simulations and experimental results provide a better understanding of electromagnetic swing blade blower design. (C) 2015 Elsevier B.V. All rights reserved.
The development of a cross-flow fan for electronic devices cooling with a focus on laptop computers
(2014-01-01)
Li, Ai-Tsung
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Hsu, Ray-Quen
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機械工程學系
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Department of Mechanical Engineering
The directive is to develop a new type of cross-flow fan for cooling electronic devices. First, the module is based on the 60X60X6mm fan and attempts to use several parameters to enhance the fan\'s performance. The parameters considered here include blade number, angle of the blade, impeller diameter, divergent structure, and outlet area. Both numerical and experimental analyses are carried out on the cross-flow fan which was oriented horizontally. The ANSYS Fluent software is used in a 2D simulation to predict the heat transfer coefficient and the flow fields. Next, the flow and acoustic noise measurements are carried out at different parameters with the aid of AMCA and semi-anechoic chambers. The results show that when the outlet vent size is 70% of fan outside diameter the outcome is an enhanced fan performance of 12%. The optimal number of blades is 37. A block is inserted below the fan blade to improve the fan performance by 8%. The numerical and experimental values of air flow were plotted and found to be consistent. In summary, this study provides a systematic process to develop a cross-flow fan that can meet the requirements for thin and light laptop computers.