Browsing by Subject "Array"
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Item A Study of Microfluidic Reconfiguration Mechanisms Enabled by Functionalized Dispersions of Colloidal Material for Radio Frequency Applications(2010-07-14) Goldberger, Sean A.Communication and reconnaissance systems are requiring increasing flexibility concerning functionality and efficiency for multiband and broadband frequency applications. Circuit-based reconfiguration mechanisms continue to promote radio frequency (RF) application flexibility; however, increasing limitations have resulted in hindering performance. Therefore, the implementation of a "wireless" reconfiguration mechanism provides the required agility and amicability for microwave circuits and antennas without local overhead. The wireless reconfiguration mechanism in this thesis integrates dynamic, fluidic-based material systems to achieve electromagnetic agility and reduce the need for "wired" reconfiguration technologies. The dynamic material system component has become known as electromagnetically functionalized colloidal dispersions (EFCDs). In a microfluidic reconfiguration system, they provide electromagnetic agility by altering the colloidal volume fraction of EFCDs - their name highlights the special considerations we give to material systems in applied electromagnetics towards lowering loss and reducing system complexity. Utilizing EFCDs at the RF device-level produced the first circuit-type integration of this reconfiguration system; this is identified as the coaxial stub microfluidic impedance transformer (COSMIX). The COSMIX is a small hollowed segment of transmission line with results showing a full reactive loop (capacitive to inductive tuning) around the Smith chart over a 1.2 GHz bandwidth. A second microfluidic application demonstrates a novel antenna reconfiguration mechanism for a 3 GHz microstrip patch antenna. Results showed a 300 MHz downward frequency shift by dielectric colloidal dispersions. Magnetic material produced a 40 MHz frequency shift. The final application demonstrates the dynamically altering microfluidic system for a 3 GHz 1x2 array of linearly polarized microstrip patch antennas. The parallel microfluidic capillaries were imbedded in polydimethylsiloxane (PDMS). Both E- and H-plane designs showed a 250 MHz frequency shift by dielectric colloidal dispersions. Results showed a strong correlation between decreasing electrical length of the elements and an increase of the volume fraction, causing frequency to decrease and mutual coupling to increase. Measured, modeled, and analytical results for impedance, voltage standing wave ratio (VSWR), and radiation behavior (where applicable) are provided.Item Investigation of the photocatalytic lithographic deposition of metals in sealed microfluidic devices on TiO2 surfaces(2009-05-15) Castellana, Edward ThomasThe research presented within this dissertation explores the photocatalytic deposition of metal carried out within sealed microfluidic channels. Micro scale patterning of metals inside sealed microchannels is investigated as well as nanoscale control over the surface morphology of the nanoparticles making up the patterns. This is achieved by controlling solution conditions during deposition. Finally, the nanoparticle patterns are used in fabricating a sensor device, which demonstrates the ability to address multiple patches within a sealed channel with different surface chemistries. Also presented here is the construction of the first epifluorescence/total internal reflection macroscope. Its ability to carry out high numerical aperture imaging of large arrays of solid supported phospholipid bilayers is explored. For this, three experiments are carried out. First, imaging of a 63 element array where every other box contains a different bilayer is preformed, demonstrating the ability to address large scale arrays by hand. Next, a protein binding experiment is preformed using two different arrays of increasing ligand density on the same chip. Finally, a two-dimensional array of mixed fluorescent dyes contained within solid supported lipid bilayers is imaged illustrating the ability of the instrument to acquire fluorescent resonance energy transfer data. Additionally, the design and fabrication of an improved array chip and addressing method is presented. Using this new array chip and addressing method in conjunction with the epifluorescence/total internal reflection macroscope should provide an efficient platform for high throughput screening of important biological processes which occur at the surfaces of cell membranes.Item Loss compensation in a plasmonic nanoparticle array(2013-05) Miller, Shannon Marie; Alú, AndreaThe problem of heavy material and radiative losses in plasmonic devices has held back their implementation for compact and high-speed data storage and interconnects. One of the most interesting solutions to this problem currently under exploration is the addition of a gain material in close proximity to the metallic nanostructures for loss compensation. Here the physics of light transport in a nanoparticle array, and the operation of gain media in contact with the structure, are described and analytically modeled. A two-dimensional array of closely spaced gold nanoparticles has been fabricated by focused ion beam milling, and its electromagnetic response in the presence or absence of a dye coating has been simulated in preparation for pump-probe optical testing. The compensation of losses via a fluorophore coating has been proven for the first time in this geometry, for a physically realized sample.Item Performance of a mobile solid state GPS linked pulsed ring down array(2011-08) Reale, David V.; Mankowski, John J.; Bayne, Stephen B.The development of mobile Pulsed Ring Down Source (PRDS) arrays requires the ability to accurately determine the relative positions of array elements at distances, and in situations, where discrete measurements are not practical. At the frequencies of interest, centimeter level accuracy is required for the array to localize radiated energy at a given target location. Global Positioning System (GPS) devices and techniques are evaluated for the purpose of position acquisition. A Monte Carlo simulation was developed that takes into account the position error, the GPS timing error, and the switch jitter of the element. The error sources are combined and used a metric to evaluate and predict the array performance. Results of the GPS device testing, as well as previous work, are used as the input parameters of the simulation to determine their viability for use in the implementation of PRDS arrays. An array of low power solid state pulsed ring down sources are used to verify the results of the Monte Carlo simulations.Item Residential Use of Building Integrated Photo Voltaics(2012-07-16) Balabadhrapatruni, AswiniBuilding Integrated Photo Voltaics (BIPVs) are devices which are manufactured to replace building components exposed to sufficient sunlight to generate energy. Photo Voltaic Roof tiles are Building Integrated components which can be used instead of traditional roofing materials. The following thesis is focused on comparing traditional, cheaper asphalt roof tiles with Photo Voltaic (PV) roofing tiles in terms of energy cost savings during their respective Net Present Values. The method used for achieving this is computer simulation made possible by software named "Solar Advisory Model" (SAM), developed by National Renewable Energy Laboratories (NREL), to simulate energy output and resultant energy costs saved. The simulations have been run on a prototype example of a model of a dwelling unit's roof area. The simulations have been repeated for 35 cities all over the U.S.A. for 5 different climatic zones on the same prototype example of the dwelling unit. Similarly, the roof area being laid with an array of PV roof tiles has been estimated for coverage by traditional asphalt roof shingles by using data from the RS Means construction costs data. The estimated costs associated with the asphalt roof area have been adjusted to a different set of 35 locations from the 5 climatic zones by using the location factor from RS Means. A statistical analysis was done to analyze the data, net present value of roofing materials being the dependent variable versus climatic zones and roofing material as the independent variables. The statistical model also included CDD (Cooling Degree Days) and HDD (Heating Degree Days) as co-variates. The results indicate that NPV (Net Present Value) of BIPV roof is significantly different from that of asphalt roof. Another statistical analysis was done to determine the effect of climatic zones on energy savings due to the use of BIPV roofing. Energy savings (in US$) was used as a dependent variable, and climatic zone as the independent variable. HDD AND CDD were also included in this model as co-variates. The results of this test indicate that both climatic zone and HDD have an effect on total energy savings.