Дисертації з теми "Liquid crystal type sensors"
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1
Воробйов, Владислав Євгенійович. "Оптичні рідкокристалічні сенсори". Bachelor's thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/35117.
Повний текст джерелаАнотація:
Дипломна робота присвячена питанням підвищення ефективності одного з основних виконавчих елементів електроніки. Ознайомлення з основними характеристиками сесорів. Аналіз шляхів оптимізації технічних параметрів датчиків рідкокристалічного градієнта тиску. Аналіз рідких кристальних сензорів акселерації, вібрацій і включення.
У роботі розглянуто башато типів сенсорів та віддано перевашу оптичному рідкокристалічному сесору в зв’язку з легкою уніфікаціею його конструкції та широким використанням в побуті. Використовуючи властивості рідкокристалічних матеріалів вдалося досягти надзвичано чутливих ті презиційних сенсорів.Thesis is devoted to improving the efficiency of one of the main executive elements of electronics. Introduction to the main characteristics of sessors. Analysis of ways to optimize the technical parameters of liquid crystal pressure gradient sensors. Analysis of liquid crystal sensors of acceleration, vibration and inclusion. The paper considers many types of sensors and prefers the optical liquid crystal sensor due to the easy unification of its construction and widespread use in the home. Using the properties of liquid crystal materials, it was possible to achieve extremely sensitive sensing sensors.
2
Lu, Jiahui. "Designing wavefront sensors from liquid crystal microlenses." Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.707989.
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3
Finnemeyer, Valerie A. "Development of Liquid Crystal Infrared Imaging Sensors." Kent State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=kent1463139065.
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4
Mak, Hin Yu. "New type transflective liquid crystal displays /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20MAKH.
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Drake, Philip. "The development of quartz crystal microbalance based chemical sensors." Thesis, University of Bath, 2000. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323573.
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6
Haddock, Joshua Naaman. "Liquid Crystal Based Electro-Optic Diffractive Spectacle Lenses and Low Operating Voltage Nematic Liquid Crystals." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1304%5F1%5Fm.pdf&type=application/pdf.
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El, Hankari Samir. "Silices hybrides nanostructurées par 'Liquid Crystal Templating' de précurseurs ioniques." Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20016/document.
Повний текст джерелаАнотація:
Une série de précurseurs contenant des sous-structures organo-ioniques à base d'entités imidazolium, guanidinium, ammonium et zwitterionique ainsi que des précurseurs neutres contenant des sous-structures amido-thiol, amine-thiol et amine a été synthétisée. Ces précurseurs ont été utilisés pour la synthèse de matériaux silices hybrides nanostructurés par voie template. La formation de matériaux nanostructurés a été réalisée par des réactions d'hydrolyse-polycondensation par l'utilisation de différents agents de structuration. Ce travail avait pour but la détermination des principaux facteurs influençant la structuration des matériaux. Ainsi, nous avons préparé une série d'ionosilicates nanostructurés par une nouvelle méthode de structuration qui met en jeu des interactions spécifiques entre des paires d'ions ‘précurseur cationique - surfactant anionique' et ‘précurseur anionique - surfactant cationique'. Cette approche a permis d'accéder aux matériaux originaux de type PMO ionique. Finalement, nous avons utilisé pour la première fois des surfactants de guanidinium comme ‘template' dans la synthèse des silices ioniques nanostructurées de morphologie sphérique. Les matériaux nanostructurés contenant des sous-structures amine, amine-thiol, ammonium et zwitterionique développés au cours de ce travail présentent des surfaces spécifiques élevées et une bonne accessibilité des sites organiques. Ces propriétés font de ces matériaux des systèmes de choix pour des applications en catalyse ou en séparationA series of precursors containing organo-ionic substructures such as imidazolium, guanidinium, ammonium and zwitterionic entities and several neutral precursors containing thiol-amide, thiol-amine and amino groups were successfully synthesized. These precursors were used for the synthesis of nanostructured silica hybrid materials containing ionic substructures via soft templating approaches. The formation of structured materials was achieved using template directed hydrolysis polycondensation procedures in the presence of various structure directing agents. The goal of this study was the determination of the parameters influencing the structuring of the materials. Thus, we prepared a series of nanostructured ionosilicates using a new method of structuring that is based on specific interactions between ‘cationic precursor - anionic surfactant' and ‘anionic precursor - cationic surfactant' ion pairs. This new strategy allowed the synthesis of ionic 'periodic mesoporous organosilicas'. At the end of this thesis, we used a new ‘guanidinium' type template in the preparation of nanostructured i-silica hybrid materials with a spherical morphology. Nanostructured ionosilicates bearing amine, amino-thiol, ammonium and zwitterionic substructures prepared in this work present high specific surface areas and a high accessibility of the organic functional sites. Due to these features, these materials have large potential in the fields of catalysis and separation
8
Murakami, Takahide. "Antiadhesion effect of the C17 glycerin ester of isoprenoid-type lipid forming a nonlamellar liquid crystal." Kyoto University, 2019. http://hdl.handle.net/2433/242411.
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9
Byun, Albert Joonsoo. "Chemical Application of Silicon-Based Resonant Microsensor." Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16296.
Повний текст джерелаАнотація:
The detection of volatile organic compounds in liquid is of interest for applications in public health, workplace safety and environmental monitoring. Traditionally, water samples were taken and analyzed in the laboratory using classical laboratory instrumentation. Current trends target real-time measurements using e.g. chemical microsensors built with microfabrication technologies. Among these, mass-sensitive chemical sensors, based on cantilever beams or surface acoustic devices, have shown substantial promise in gas-phase applications. In a liquid environment, the resonant microstructures typically suffer from high damping, which negatively affects the sensor resolution. In this work, a novel disk-type resonator developed at Georgia Tech was investigated as chemical microsensor for liquid-phase applications. The micromachined resonator vibrates in a rotational in-plane mode shape, reducing damping in a liquid environment. As part of the present research, a measurement setup with a custom-made flow cell for liquid-phase chemical measurements and a coating system to locally deposit polymer sensitive films onto the resonators were developed. To improve the film adhesion on the resonator surface in liquid, physical and chemical binding techniques were developed and tested on wafer samples. Polymers such as poly(4-vinylpyrrolidone), poly(ethylene-co-propylene) and poly(styrene-co-butadiene) were deposited using the custom-designed coating system onto the disk-type resonators. Liquid-phase measurements using tetrachloroethylene as the chemical analyte were performed. The experimental results are discussed, sources of problems are identified and recommendations for future research are made.
10
LI, ZHE. "Photocyclodehydrofluorination (PCDHF) –A synthetic method for fluorinated polynuclear aromatic hydrocarbons." Kent State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=kent1448814689.
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11
Rydh, Andreas. "Vortex Properties from Resistive Transport Measurements on Extreme Type-II Superconductors." Doctoral thesis, KTH, Physics, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3288.
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12
Tebow, Christopher. "A Tunable Snapshot Imaging Spectrometer." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1023%5F1%5Fm.pdf&type=application/pdf.
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13
Conteau, Delphine. "Développement d’outils pour l’étude des écoulements diphasiques dans les canaux d’une pile à combustible de type PEM." Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL036N/document.
Повний текст джерелаАнотація:
Parmi les nombreuses problématiques liées à la PEMFC, l'eau est un point crucial car elle est à la fois indispensable et indésirable dans le coeur de pile. En effet, les flux gazeux qui alimentent le système en réactifs sont humidifiés pour que la membrane soit convenablement hydratée afin de faciliter le transport des protons de l'anode vers la cathode. Mais à cet apport initial vient s'ajouter l'eau produite par la réaction électrochimique. Des gouttes d'eau liquide peuvent alors se former dans les pores des couches actives et peuvent grossir jusqu'à boucher les canaux des plaques d'alimentation en gaz. Ce travail de thèse est centré sur l'étude des écoulements gaz-liquide dans ces canaux, dont le diamètre hydraulique est de l'ordre du millimètre. Dans un premier temps, des micro-capteurs ont été mis au point pour détecter la présence d'eau liquide. Après une phase de tests en maquette froide, ces micro-capteurs ont été insérés dans une cellule de 25 cm2 de surface active, identique à celles étudiées au LRGP. Ceci a permis de montrer que dans une pile en fonctionnement, les fluctuations de tension sont liées à la présence d'eau liquide. Par ailleurs, des corrélations existantes ont été utilisées pour prédire les pertes de charge engendrées par la présence de deux phases dans les mini-canaux. Ces calculs ont été comparés aux mesures expérimentales, mettant en évidence l'influence de la couche de diffusion des gaz, située entre les canaux et la membrane, et l'importance des conditions opératoires.Ces méthodes originales viennent compléter les outils de diagnostic existants sans demander d'appareillage complexe et coûteux, ni nécessiter le développement de matériel spécifique, non optimisé pour une utilisation commercialeWater management is a critical issue in the operation of proton exchange fuel cells (PEMFC). On one hand, the membrane must be sufficiently hydrated to allow the transport of protons from the anode side to the cathode side. But on the other hand, supersaturation of water vapour in the gas phase results in liquid water formation, which can be detrimental to the fuel cell operation. Liquid water can clog up the porous structure of the gas diffusion layer (GDL) and hinder the transport of gases in the catalyst layer. Liquid accumulation can also lead to the formation of water columns inside the gas flow channels, thus preventing the fuel gas from flowing into the reaction area.Micro-sensors have been designed to detect the presence of liquid water. Three of them were inserted inside the gas distribution channels of a 25 cm2 cell. The tests run with this equipped cell highlighted the link between the presence of liquid water and the variations of the cell voltage. Besides, existing correlations were used to calculate the pressure drop between the inlet and the outlet of the cathode channel due to two-phase flow during the cell operation. The results of this calculation were compared with experimental results. This part of the study highlighted the influence of the GDL and of the operating conditions on the flows inside the channels
14
Lopatina, Lena M. "Statistical Mechanics of Nanoparticle Suspensions and Granular Materials." Kent State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=kent1310414818.
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15
Chou, Fang-Fei, and 周芳妃. "Preparation and Application of Chemical Electrode Piezoelectric Crystal Liquid Sensors." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/01761943986120361586.
Повний текст джерелаАнотація:
博士國立臺灣師範大學
化學系
96
An electrochemical electrode/surface acoustic wave (ESAW) system was developed to explore the possibility of the application of UHF waves, 300–3000MHz for chemical analysis in solution. The ESAW system with a ST-cut surface-acoustic wave (SAW)/quartz transducer was prepared for detection of metal ions and glucose in aqueous solutions. The ESAW system has the advantages of very low cost, easy fabrication and detection without quick energy-loss. The ESAW system was an on-line detection system and it was built-up by the interference on the fringing electric field of the ST-cut SAW quartz resonator. A set of electrodes welded with long-distance wires and coaxial cables was used to contact to the metal shell of the 315MHz SAW quartz resonator. The ESAW system was applied to detect various metal ions, e.g., alkaline metal, alkaline-earth metal and transition-metal ions. Without pre-concentration technique, the detection limit of Cu2+ ion with the ESAW detection system was estimated to be 1.2 × 10−4 mol L-1 (i.e. 7.6 ppm, from an analytical sensitivity of 2.55 × 105 Hz/(mol/L) and the standard deviation of the blank signal of 10 Hz with a confidence level of 99.86 %. The ESAW detection system was also applied as a biosensor for glucose to detect the glucose oxidation reaction by glucose oxidase (GOD) in aqueous solutions. The glucose oxidase (GOD) enzyme-catalyzed system was also studied on the detection of glucose / H2O2 mixture. The glucose ESAW biosensor with glucose oxidase exhibited a linear frequency response to the log concentration of glucose with a slope of approximately 9.3 × 102 Hz decade−1 (Hz/logM). The ESAW detection system also showed a good selectivity and a good detection limit of < 10−3M for glucose in aqueous solution. Furthermore, the ESAW detector showed much more sensitive than QCM crystal sensor for glucose. QCM crystal sensors for long-chain fatty acid and the cholesterol ester were also built up by using the AT-cut quartz crystal with fullerene C60-cyptand-22 coating. The QCM crystal sensors detected the long-chain fatty acid and the cholesterol ester concentration in a non-ionic surfactant emulsion solution. The hydrolysis of cholesterol ester was carried out with catalysts of free and fullerene C60-immobilized cholesterol esterase, respectively. The detection limit of cholesterol with the QCM crystal sensors was estimated to be 62 μM in good comparison with the clinical spectroscopic method. The clinical spectroscopic method is a tri-enzyme reactions system with very expensive cost but the QCM cholesterol sensors with fullerene-immobilized cholesterol esterase was a mono-enzyme system with low cost substantially for the quantitative measurement of cholesterol.
16
Lin, Hung-Yuan, and 林宏遠. "Edge-light Scattering Type Transparent Liquid Crystal Displays." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/6wxunb.
Повний текст джерелаАнотація:
碩士國立中山大學
光電工程學系研究所
107
In recent years, see-through display captures much attention as next-generation displays, because it can have virtual image and background view at the same time. Therefore, transparent displays have the potential for integrating with smart windows, smart phones, outdoor advertising billboards, vehicular head-up windows, augmented reality and even building outlook. It also can provide interactive experience of entertainment, navigation, advertising, education according to the demand of consumers. At present, there are many technologies that can simultaneously display background and information, but they both can’t achieve transparent state with high transmittance and low operating voltage required for active matrix driving circuit design. They limit the development and application of transparent display. However, some groups used polymer network liquid crystals to develop transparent displays with edge-light sources. The scattering property of polymer network liquid crystals can replace polarizer, and color sequential method replace color filters due to fast response time. Therefore, based on the two properties, the transparent state with the transmittance more than 80% is expected to be achieved. In addition, longer lateral scattering paths allow the thin cell gap of liquid crystal still have a high contrast, so that the operating voltage can be reduced to make the devices integrated with the active matrix driving. Based on this edge-light scattering method, we continue to study the polarization dependence mechanism of incident light and scattered light, material selection, and the influence of polymer structure on electric-optical characteristics, and finally optimizes devices. In this research, we achieve excellent electro-optical properties: operating voltage is 13V, response time is about 2.1ms, the contrast ratio is about 30, and transmittance of transparent state is nearly 80%, which can apply to the color sequential method and the active matrix driving. We discuss the voltage holding rate of material and the collimation of the light source for the future application of the display. We believe this technology has considerable potential in the future for transparent displays and augmented reality.
17
CHEN, JIAN-YONG, and 陳健湧. "Synthesis and characterization of polyester type liquid crystal polymers." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/53864074933054277247.
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18
XIN, ZHE-HONG, and 辛哲宏. "Relationship between composition and properties of polyester type liquid crystal polymer." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/73105604642832987716.
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19
Huang, Yu-Sheng, and 黃裕盛. "The Reflection Properties of Dye Guest-Host Type Cholesteric Liquid Crystal." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/23232569373952958396.
Повний текст джерелаАнотація:
碩士國立臺灣科技大學
纖維及高分子工程研究所
87
The influence on reflectivity of cholesteric liquid crystal were researched. The cholesteric liquid crystal and the dye guest-host type cholesteric liquid crystal without polarizer and reflector were manufactured. The cell just need a transient voltage in the initial planar（ON）and focal conic（ＯＦＦ）state that it will reach the aim of switch; moreover, the cells don''t need applied voltage continuously when they maintain in planar（ON）or focal conic（ＯＦＦ）state. Besides, They have the merit of high brightness without back light. We used the following equipment: polarizing microscope, arbitrary waveform generator, digital oscilloscope, polarizing micro-spectrometer, and hot stage to study the physical properties of dye guest-host type cholesteric liquid crystal. The result indicated that cholesteric liquid crystal has different electric-optical properties when we use different chiral dopant; for example, the dependence of pitch length and temperature. The cholesteric liquid crystal phase transition temperature decreases with increasing chiral dopant contents. In addition, the changes of applied voltage will effect the reflectivity of cholesteric liquid crystal. Because dye absorb some light and the part of incident light will train to heat, the reflectivity of cell will change. When the content of dye increases, the wave of reflectivity will change. If the temperature changes, the wave of reflectivity changes remarkably, too. During the measure of view angle, we found the view of cell was bad, and they have a shortcoming that the different view angle will reflect different colors.
20
Shieh, Meng-Shiun, and 謝孟勳. "Investigation on the Properties of a Reflective Type Nematic Liquid Crystal Display." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/09249363852690022355.
Повний текст джерелаАнотація:
碩士國立交通大學
光電(科學)研究所
83
A new reflective type LCD, comprising one polarizer, one re- tardation film, and one HAN（Hybrid-Aligned-Nematic）cell with a metal electrode inside, is studied in this thesis. The excellent properties of low power consumption, wide viewing angle, and full-color capability, promise its potential application in the portable personal information tools. In theory, we calculated the director distribution of HAN liquid crystal and the optical performance of the device with phase compensated film by using Euler-Lagrange equation and Extend 2x2 Jones Matrix method, respectively. According to the simulated result, we can find the material parameters of the compensator and make it. In experiment, we set up the measuring system to observe the performance of the whole device and compare the experimental results with the simulated ones. This will help us to realize the characteristics of HAN type LCD. According to the experiment, we find the contrast ratio under red light is smaller than the one under the green light. There- fore, we will discuss the influence of HAN type LCD by material dispersion and provide the suitable operation mode to solve the problem of light leakage under the different wavelength. We take an integrated conclusion in the end of the thesis.
21
Wang, Hsuan-Wen, and 王宣文. "Simulation and the fabrication of focus-tunable Fresnel-type liquid crystal lens." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/w9bhr3.
Повний текст джерелаАнотація:
碩士國立臺灣大學
光電工程學研究所
107
In this research, the simulation and the fabrication of the Fresnel-type liquid crystal lens is demonstrated. The simulation is about how to simulate how Fresnel-type electrodes which is being applied voltage will affect the liquid crystal cell. We hope the lens can solve the problem of nearsighted user of VR/AR. So we would like to design a lens with a diameter of 12 mm which can cover human’s pupils. We choose to make a GRIN lens with Fresnel type to gain more diopters. After the simulation of the lens, we use Precision Machining to make the mold of the Fresnel-type electrodes and mold it with PDMS and NOA65 to make a transparent Fresnel lens structure. After we spin-coated PEDOT:PSS on the lens, we can get a Fresnel type electrode. Then we’ll fill in the electrode with SU-8 photoresist and assemble it with a plastic spacer and ITO glass. After the liquid crystal is filled within the gap between SU-8 photoresist and ITO glass, we can finally get a prototype of a Fresnel-type liquid crystal lens. The interference pattern is measured by CCD and the imaging of the lens is observed by CMOS. We can measure the optical power by interference pattern. The diopter ranges from 0 to 8.9 Diopters and is good for nearsighted correction in VR/AR system and also for optical zoom system and focus-tunable lens applications.
22
Chou, Fu Lung, and 周府隆. "Fusion of holographic floating Images generated with phase type liquid crystal on silicon." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/50602949232437180957.
Повний текст джерелаАнотація:
碩士國立清華大學
動力機械工程學系
104
A research of fusion image from a floating imaging system has been studied in this thesis. Liquid crystal on silicon (LCoS) has been used as display screen and the system light source is light emitting diode (LED). However, images can be seen directly from eye without damaging. The holographic image cannot be reconstructed by LED because it is not a coherence light source. But the spatial coherence can be enhancing by placing a finite pinhole in front the LED. The image is coding by computer-generated hologram (CGH) method. Load the hologram pattern which contain the information of a three-dimensional image on to LCoS panel, and use modified partial coherence LED source to reconstruct the image on the panel. A concave mirror is re-imaging the virtual image into space. And produce a real image with depth information without occupying any space. Since the viewing angle of the hologram, which is the diffraction angle of the panel is determined by the pixel size of the panel. The viewing angle of LCoS panel used in our floating image system is too narrow for an imaging system. Therefore, we attempt to calculate the CGH for a particular angle by simulated incident light in different angle. And extend the viewing angle of LCoS panel by fuse the image comes from different view of angle. So that the observers can see the image from different angle.
23
Wang, Yao-Tung, and 王耀東. "Optical efficiency optimization for a direct type backlight of the liquid crystal display." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/18891461899934239023.
Повний текст джерелаАнотація:
碩士元智大學
機械工程學系
92
This thesis is on optical efficiency optimization for a direct type backlight of the liquid crystal display. The goal is to get the greatest uniformity in a direct type backlight, while the brightness is maintained in a satisfactory level. Both uniformity and brightness are implicit functions that have to be evaluated by optical simulation software Speos. This research will adjust the geometric dimensions, which are discrete design variables, to get the best optical efficiency. The Sequential Neural Network Approximation Method (the SNA method) is used in this research. In the SNA method, two back-propagation neural network are trained to simulate the rough maps of the feasible domain and the objective function of this optimization problem using a few representative training data. A search algorithm then searches for the “optimal point” in the feasible domain and the objective function simulated by the neural network. This new design point is simulated by the optical simulation software to check its true objective values and whether it is feasible. This new information is then added to the training set and the neural network is trained again. Then we search for the “optimal point” in this new approximated feasible domain again. This process continues in an iterative manner until the approximate model insists the same “optimal point” in consecutive iterations. In this thesis, a two-variable example is used to illustrate the process of SNA. A four-variable optical efficiency optimization problem for a direct type backlight of the liquid crystal display is then solved using the SNA method. In both examples, the number of optical simulations required is greatly reduced.
24
Chia-EnWu and 吳佳恩. "Designs of Optical Pixel Sensors for Thin-Film Transistor Liquid Crystal Displays with Optical Input Functions." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/krzzs4.
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25
Zheng, Wei-Ding, and 鄭惟頂. "Liquid refractive index measurements by uses of D-type multi-mode fiber sensors and the ATR prism type sensor." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/8e7s4a.
Повний текст джерелаАнотація:
碩士國立虎尾科技大學
光電與材料科技研究所
97
In this study, we propsed two methods for liquid refractive index measurements by uses of D-type multi-mode fiber sensors and the ATR prsim type sensor. 1. A multi-mode D-type optical fiber sensor based on the surface plasmon resonance(SPR), attenuated total reflection(ATR) and using optical spectrum analyzer method is presented. It is coated with an Au-film layer with a thickness of 20~50nm to detect the refractive variation of a liquid by measuring the output spectrum. Calculation of the reflectance ratio of the specimen, compared to water, enables determination of the resonant wavelength and the refractive index. The proposed method is used to enhance the measurement sensitivity and achieve a resolution to 5.2×10-7(RIU). 2 Being different with the usual SPR prism type sensor, a novel measurement system based on attenuated total reflection(ATR) with S polarization was built up in our Lab. For measuring the liquid refractive index, we used five-layers ATR sensors to simulate its attenuated angles corresponding different refractive index liquid and the best coating thickness. Comparing the resoulation between S- and P-polarizations, the S-polarized ATR sensor is better than the P-polarized SPR sensor, and the resoulation can achieve to 1.89×10-6 (RIU). The results exhibits that is feasibility to use S-polarization for measurement.
26
Hsiao, Chi-Lin, та 蕭祺霖. "Fabrication of array-type dopamine sensors using ultrasonic liquid atomizer for spraying γ-APTES/SiO2 bionanocomposite". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/72399870932952718484.
Повний текст джерелаАнотація:
碩士國立暨南國際大學
應用材料及光電工程學系
101
The purpose of the thesis is to use the ultrasonic liquid atomizer to spray the sensing membrane of a mixture of 3-aminopropyltriethoxysilane (γ-APTES) and polydimethylsiloxane (PDMS)-treated hydrophobic fumed silica nanoparticles (NPs) onto a polysilicon wire (PSW), investigating the characteristics of electrical interference of the PSW in detectingthe nerve substance of dopamine. The ultrasonic liquid atomizer we used might rapidly spray the γ-APTES+NPs onto the PSW with the advantages of large-area production as well as with good uniformity of the film. We used two methods to do the dopamine detections: 1. Using the 4-carboxyphenylboronic acid (CPBA) to modify the surfaces of γ-APTES- or γ-APTES+NPs-coated PSWs. The CPBA molecules were then used as interfacial layer for bonding dopamine molecules (CPBA modification method). 2. Using the tyrosinase to mix with dopamine solution to produce the hydrogen ions. The γ-APTES- or γ-APTES+NPs-coated PSWs were then used to capture the hydrogen ions (tyrosinase conversion method). We found the optimal conditions for sensitivity through changing the weight ratio of NPs/γ-APTES or the volume ratio of (γ-APTES+NPs)/C2H5OH. It was found that, for both the CPBA modification and tyrosinase conversion methods, the optimal conditions for two methods were the same, that is, the weight ratio of the NPs to γ-APTES was 1% and the volume ratio of the γ-APTES+NPs to C2H5OH was 0.2%. For the optimal conditions, the dopamine sensor exhibited the best performance of sensitivity and linear detection region in dopamine detections. For the CPBA modification method, the lowest detection limit is 10-6 M, and the linear region is in the range of 10-3 M ~ 10-6 M. For the tyrosinase conversion method, the lowest detection limit is 10-11 M, and the linear region is in the range of 10-3 M ~ 10-11 M. We found that the tyrosinase conversion method is better than the CPBA surface modification method. Neverthless, both methods can be used for dopamine sensing application. We successfully fabricated the low-cost dopamine biosensor array by batch production using the ultrasonic atomizing for spraying the large–area γ-APTES +NPs membrane with good uniformity.
27
Tsai, Kai-Hsun, та 蔡凱勛. "Fabrication of array-type glucose sensors using ultrasonic liquid atomizer for sprying γ-APTES/SiO2 bionanocomposite". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/17244784853860831648.
Повний текст джерелаАнотація:
碩士國立暨南國際大學
應用材料及光電工程學系
101
The aim of this thesis focuses on the film deposition of γ-APTES mixed with PDMS-treated silica nanoparticles (NPs) by ultrasonic liquid atomizer for sensor applications, investigating the effects on glucose sensing property of the film in different NPs/γ-APTES weight ratio, different γ-APTES/C2H5OH concentration ratio, and ultraviolet (UV) light exposure. The reason we deposit the γ-APTES+NPs nanocomposite thin film on poly-silicon wire (PSW) by an ultrasonic liquid atomizer is that we might fabricate the glucose sensors array by batch production. We first characterize the surface morphology and measure the vertical leakage current by using atomic force microscopy (AFM). Then, the sensitivity of glucose sensors array is analyzed. It is found that the vertical leakage current of the sensing film increases with NPs/γ-APTES weight ratio in the range of 0% to 1%, and increases with the concentration ratio of (γ-APTES+NPs)/C2H5OH. In comparing the distribution of the values of vertical leakage current, we prove that a uniform γ-APTES+NPs nanocomposite thin film is successfully deposited by using ultrasonic liquid atomizer method. We find that the permance of the batch fabricated glucose sensor array is nearly as good as our previous result which was fabricated by AFM tip coating method. According to our experimental results, the optimal conditions for the glucose detection are 1% weight ratio for NPs/γ-APTES, 1% concentration ratio for (γ-APTES+NPs)/C2H5OH and 120 s for UV exposure. The lowest detection limit is less than 10-9 M, and the linear detection region is from 10-2 M to 10-7 M. Comparing with our previous results, the lowest detection limit and the linear region are nearly the same as the tip-coating method. The sensitivity is about 80% of that tip-coating result. The ultrasonic liquid atomizer spray method can effectively reduce the costs and simplify the process to achieve the goal of a rapid production for large area of sensing membrane.
28
CHENG, CHIA-CHENG, and 鄭加誠. "The study on its electro-optical characteristics of polymer aligned vertical type of liquid crystal cells." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/m7f5p8.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
光電工程系
107
A simple alignment method is proposed to fabricate the vertically aligned (VA) liquid crystal (LC) cells. Two kinds of monomer materials (polymer A and polymer C) with different networking properties are mixed together with the specific ratio to make liquid crystals vertically aligned. This paper demonstrates that a new vertically aligned method applied to the LC cells not only avoid the complicated process, but also is superior to the conventional process.
29
Tsao, Jung-Chun, and 曹榮峻. "Applying MEMS Thermal Film Sensors Array and Liquid-crystal Flow Visualization Technique on Investigating Flow Reattachment over a Surface-mounted Rectangular Block." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/90022010211273672690.
Повний текст джерелаАнотація:
碩士國立成功大學
航空太空工程學系碩博士班
94
Abstract Subject：Applying MEMS Thermal Film Sensors Array and Liquid-crystal Flow Visualization Technique on Investigating Flow Reattachment over a Surface-mounted Rectangular Block Student：Jung-Chun Tsao Advisor：J. J. Miau The purpose of this paper is to investigate the three-dimensional, unsteady behaviors of flow reattachment over a surface-mounted rectangular block, whose ratio of width versus height of the block is equal to 4. The cholesterol- type liquid-crystal mixed with toluene and oligomer (one kind of polymer) has been used as a non-intrusive means of flow visualization. The temperature range of the liquid-crystal is between 43℃and 60℃, and the uncertainty can be less than 0.9%. As found from the liquid-crystal flow visualization, the reattachment length is around 3.15H, for the Reynolds numbers at 3.17×104, 4.22×104, and 5.12×104, respectively. The finger-type structures inferring the three- dimensional vortices stretched in the reattachment region on the top of the model have been found in the visualization. There are approximately four finger-type structures located near the trailing edge of the model, and all of its spanwise length scales are around 1H. The intensity of the finger-type structures are varying with time, but almost fixed spatially. Also, the three-dimensional unsteady behavior of the flow reattachment over the surface-mounted rectangular block can be comfirmed by the digital image (hue level) analysis of the visualization. In order to verify the result of the visualization, the self-made MEMS thermal film sensors and the X-type hot-wire were further employed. The DC amplifier circuit was in corporated with the thermal tuft. The cross-correlation analysis of the thermal film signals and hot-wire signals were made to gain better understandings on flow reattachment and finger-type structures. It has been found that the reattachment length is between 3.2H and 3.5H, and the dimensions of each finger-type structures are between 0.99H to 1.1H. The results obtained are consistent with those obtained by the liquid-crystal visualization.
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Chu, Chieh, and 朱傑. "Design and Synthesis of Heterocyclic Discotic Liquid Crystal Materials and Their Application for N-Type Organic Field-Effect Transistors." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/31158758789179624794.
Повний текст джерелаАнотація:
碩士國立臺灣大學
化學研究所
95
Three series of quinoxaline-based liquid crystal materials with or without semifluorinated alkyl chains have been successfully synthesized. Their thermal stabilities, reduction potentials, and mesophase characteristics have been examined by TGA, CV, POM, DSC, and temperature-dependent PXRD, respectively. The molecular orientation and their film morphology on the substrate (SiO2/Si) with or without SAMs also have investigated by PXRD and AFM. The control of molecular orientation, to be perpendicular to the substrate treated with PFTS via fluorophilic/fluorophobic interaction, has been achieved. This method provides a new molecular design principle enabling desired molecular alignment of organic semiconducting materials for organic field-effect transistors.
31
Wang, Chun-yu, and 王峻禹. "Developing a liquid crystal lens with tunable focal length and type of focus by controlling the electric field distribution." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/43662607165532649306.
Повний текст джерелаАнотація:
碩士國立中山大學
物理學系研究所
93
By using a special design of electrode pattern and the differential biased circuit, the gradient of the electric field distribution inside the liquid crystal sample cell can be achieved through the adjustment of driving voltage. The characteristics of positive or negative types of lens can be converted by changing the polarity of gradient within the sample cell which posses the homogeneous alignment. The liquid crystal lens with a variable focal length and the tunable types of focusing is demonstrated by utilizing the controllable distribution of electric field. This special design incorporating with the fabrication technology of TFT has a potential to develop a large scale of liquid crystal lens.
32
Chu, Chieh. "Design and Synthesis of Heterocyclic Discotic Liquid Crystal Materials and Their Application for N-Type Organic Field-Effect Transistors." 2007. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2307200723250100.
Повний текст джерела
33
Chen, Jhe-chang, and 陳哲昶. "Study of homeotropic adsorption effect on azo-dye-doped polymer-ball-type polymer-dispersed liquid crystal films and its applications." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/62627929439246606594.
Повний текст джерелаАнотація:
碩士國立成功大學
光電科學與工程研究所
96
This thesis investigates the mechanism of light-induced azo dye adsorption in dye-doped polymer-ball-type polymer-dispersed liquid crystal (PBT-PDLC) films. The experimental results show that the dyes are adsorbed onto the UV cured polymer film with their long axes being perpendicular to the substrate surface if an optimized AC voltage is applied during optical-patterning. After the applied voltage is switched off, the adsorbed dyes remain the same alignment, and align the liquid crystals homeotropically in the PBT-PDLC sample. In addition, the dyes adsorbed onto the polymer layer can be desorbed by thermal disturbance, and then be re-adsorbed onto the layer following the optical recording mentioned above. The mechanism is applied to fabricate laser-induced intensity gratings and polarizer-free liquid crystal displays. The electro-optical phenomena and the fabrication processes are analyzed. The results show that the laser-induced grating is an amplitude grating. Besides, the liquid crystal display can be switched by applying a voltage, then erased by a thermal disturbance and rewritten optically. The measured switching time is in the order of milliseconds (~ 60 ms), and the contrast ratio is measured to be about 30.
34
Chang, Jen-chung, and 張仁忠. "A Study of the Electro-Optic Characteristics of Chiral-doped Negative Type Nematic Liquid Crystal in the Vertically Aligned Cell." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/4t7cfj.
Повний текст джерелаАнотація:
碩士國立中山大學
光電工程研究所
96
Recently, Iwamoto[1] has proposed a passive-matrix LCD called VA-STN-LCD (Verically Aligned Super Twist Nemetic LCD), in which excellent electro-optic (EO) performance under high-multiplexing conditions has been demonstrated. It was pointed out that such a high EO performance was realized by achieving a pretilt angle of about 80 degree. In this study, we want to learn the different EO characteristic of separate pretilt angle and separate chiral-doped concentration of Negative Dielectric Anisotropy nemetic liquid crystal in vertically aligned cell.
35
Gour, Abhay Singh. "Design And Development of Linear Moving Magnet Synchronous Motor Based Twin PTC And HTS Level Sensor for LOX Recondenser." Thesis, 2016. http://etd.iisc.ernet.in/handle/2005/2673.
Повний текст джерелаАнотація:
Cryocoolers are closed cycle devices which produce cooling below 120 K. Usually, one or two linear motors are used to drive one pulse tube cryocooler. Cryocoolers are used for various applications like, cooling of infra red detectors, cryo surgical knife, cryogen recondenser etc.
In this thesis the design development and testing of Twin Pulse Tube Cryocooler (TPTC) are discussed. TPTC consists of two pulse tubes driven by dual piston head linear compressor. This dual piston linear compressor is operated using single linear motor. Using this configuration, cooling power is doubled with reduced cost of compressor. The design, fabrication and testing of Linear Moving Magnet Synchronous Motor (LMMSM) based dual piston head linear compressor are carried out indigenously. Finite Element Method (FEM) analysis is used for estimating eddy current loss and flux distribution pattern in various mover configurations of the linear motor. The developed fabrication and assembly procedure of linear motor are discussed in detail.
The mover of linear motor is supported by using a pair of cross armed C – type flexures. These flexures are designed using FEM and are fabricated indigenously. The flexure pairs are tested for 108 cycles with ± 3 mm stroke length of linear motor before assembling compressor.
Linear motor is usually required to be operated at different frequencies. Thus, a variable frequency and variable voltage Pulse Width Modulated (PWM) based power supply is designed using analog circuits like Op-Amps. This cost effective power supply is capable of delivering 27 A at 100 V with frequency range of 25 Hz to 80 Hz continuously.
Sage software was used to carry out 1-D simulation and obtain dimensions of various Pulse Tube Cryocooler (PTC) components. Various pulse tube configurations like Joint Twin PTC, Twin PTC with buffer volume and single PTC with buffer volume were carried out. A Computational Fluid Dynamics (CFD) Fluent 2-D analysis was carried out for single PTC with buffer volume. The fabrication and assembly procedure of PTC is discussed in detail. A novel method of heat exchanger fabrication was developed and analyzed using FEM and its performance is tested experimentally. The twin PTC is operated at 34 bar and 48 Hz.
A light weight High Temperature Superconductor (HTS) based level sensor is developed to monitor the cryogen level. The developed sensor was calibrated against discrete diode array and pre-calibrated continuous capacitance type level sensor. The calibrations were carried out in indigenously designed and fabricated 4-wall cryostat using Liquid Nitrogen (LN2) and LOX as cryogen.
LabVIEW software based data acquisition was designed for testing, recording and monitoring the performance of twin PTC and level sensors during experiments.