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Full-Text Articles in Physical Sciences and Mathematics
Tracking Real-Time Nanoparticle Positions And Measuring Three-Dimensional Solution Flow With A Four-Focus Confocal Microscope, James Andrew Germann
Tracking Real-Time Nanoparticle Positions And Measuring Three-Dimensional Solution Flow With A Four-Focus Confocal Microscope, James Andrew Germann
Doctoral Dissertations
This dissertation presents the development of instrumentation for measuring the position of a single emitter within the sample volume of a confocal fluorescence microscope with sub-diffraction limited precision in three dimensions together with applications for determining solution flow and for tracking a fluorescent nanoparticle as it undergoes Brownian diffusion. The localization method is based on comparing photon counts from alternating excitation of the emitter by four laser beams, which are focused at slightly offset positions in a tetrahedral pattern within the confocal volume. Two experimental set-ups are constructed. In the first, the four beams are from a femtosecond laser, which …
Three-Dimensional Electrokinetic Trapping Of A Single Fluorescent Nanoparticle In Solution, Jason Keith King
Three-Dimensional Electrokinetic Trapping Of A Single Fluorescent Nanoparticle In Solution, Jason Keith King
Doctoral Dissertations
This dissertation presents the development of an instrument for effectively trapping a single fluorescent nanoparticle that is freely diffusing in solution in all three dimensions. The instrument is expected to have applications for studies of single nanoparticles or molecules for which prolonged observations are required, but without immobilization or proximity to a surface, which may alter behavior. The trapping technique depends on rapid three-dimensional position measurements of the nanoparticle with sub-micron precision, which are used for real-time control of induced electrokinetic motion, so as to counteract Brownian motion. While anti-Brownian electrokinetic trapping experiments in one and two dimensions have previously …
Femtosecond Laser Patterned Templates And Imprinted Polymer Structures, Deepak Rajput
Femtosecond Laser Patterned Templates And Imprinted Polymer Structures, Deepak Rajput
Doctoral Dissertations
Femtosecond laser machining is a direct-write lithography technique by which user-defined patterns are efficiently and rapidly generated at the surface or within the bulk of transparent materials. When femtosecond laser machining is performed with tightly focused amplified pulses in single-pulse mode, transparent substrates like fused silica can be surface patterned with high aspect ratio (>10:1) and deep (>10 μm) nanoholes. The main objective behind this dissertation is to develop single-pulse amplified femtosecond laser machining into a novel technique for the production of fused silica templates with user-defined patterns made of high aspect ratio nanoholes. The size of the …