This thesis presents optofluidic nanostructures for analyte transport, concentration and sensing. This work was part of a larger collaborative project between the BC Cancer Agency and the departments of Chemistry, Electrical and Mechanical Engineering at the University of Victoria. In this work, arrays of nanoholes are used as optofluidic platforms for sensing, combining the characteristics of these nanostructures for both fluidic transport and plasmonic (optical) sensing. Two different modes are considered: flow-over mode, where the sample solution containing the analyte flows on top of the nanohole arrays, and a novel flow-through mode, where the nanoholes are used as nanochannels, enabling solution transport and analyte sieving. Flow-through nanohole array operation and sensing is first demonstrated, offering a six-fold improvement in sensor response compared to established flow-over sensing formats. Through a subsequent theoretical scaling analysis and computational analyses, the benefits of the flow-through nanohole sensing format are further quantified. A first analysis is dedicated to study the enhancement offered by the flow-through operation mode using a mass transport approach. A second analysis offers an ample study of benefits and limitations of the flow-through nanostructure operation using the combination of mass transport and binding kinetic parameters for different analytes with characteristics of clinical relevance. The mass transport analysis indicates much higher analyte collection efficiency (~ 99%) offered by the flow-through mode, compared to the flow-over platform (~ 2%). The analysis including both mass transport and binding kinetics demonstrate up to 20-fold improvement in response time for typical biomarkers. This thesis also presents the use of the flow-through optofluidic platform as an active analyte concentrator. In combination with a pressure bias, an electric field is used to concentrate electrically charged analyte for subsequent sensing. Fluorescein enrichment of 180-fold in 60 s was achieved, and 100-fold enrichment and simultaneous surface plasmon resonance (SPR) sensing of a protein (bovine serum albumin, BSA) was demonstrated. These experiments represent the first active utilization of a nanohole metallic layer as an electrode, and the first demonstration of a photonic nanostructure achieving both concentration and sensing of analytes. Towards the integration of optofluidic nanostructures into microfluidic environments for portable lab-on-chip diagnostic systems, this dissertation also includes the development of two nanohole array based sensing systems with simple flow-over operation. The first system consisted of a hand-held device with a dual-wavelength light source to increase the spectral diversity. The second system consisted of nanohole arrays integrated with a microfluidic concentration gradient generator for the detection and quantification of ovarian cancer antibody and antigen. Additionally, this dissertation includes a novel technique to actuate liquids in microchannels through ground-directed electric discharges. Experiments demonstrate average fluid velocities on the order of 5cm/s and applicability of the technique in serpentine channels, for on-demand fluid routing, to initiate a mixing process, and through an on-chip integrated microelectrode. / Graduate

No description available.

In this study, detailed characteristics and performance assessment of 3&amp / #8722 / 5 &micro / m p-i-n InSb photodetectors on Si substrates are reported. The detector epilayers were grown on GaAs coated Si substrates by molecular beam apitaxy (MBE). Both homojunction and single heterojunction (AlInSb/InSb) detector structures were investigated. Arrays of 33x33 &micro / m2 detectors were fabricated and flip-chip bonded to a test substrate for detailed electrical and optical characterization. A peak detectivity as high as 1x1010 cmHz1/2/W was achieved with InSb homojunction detectors on Si substrate in spite of the large lattice mismatch between InSb and Si (%19). In both homojunction and single heterojunction structures the differential resistance is significantly degraded by trap assisted tunneling (TAT) under moderately large reverse bias and by ohmic leakage near zero-bias. While the heterojunction structures provide a higher 80 K zero bias differential resistance, the responsivity of this structure is significantly lower than that of homojunction InSb photodiodes. In both homojunction and heterojunction photodetectors, 80K 1/f noise is dominated by TAT processes, and the noise current at 1 Hz follows the empirical relation in= &amp / #945 / TAT(ITAT) &amp / #946 / with &amp / #945 / TAT&amp / #8764 / 1.1x10&amp / #8211 / 6 and &amp / #946 / &amp / #8764 / 0.53.

Field programmable gate arrays are a class of integrated circuit that enable logic functions and interconnects to be programmed in almost real time. They can implement fine grained parallel computing architectures and algorithms in hardware that were previously the domain of custom VLSI. Field programmable gate arrays have shown themselves useful at exploiting concurrency in a range of applications such as text searching, image processing and encryption. When coupled with a microprocessor, which is more suited to computation involving complex control flow and non time critical requirements, they form a potentially versatile platform commonly known as a Reconfigurable Computer. Reconfigurable computing applications have traditionally had the exclusive use of the field programmable gate array, primarily because the logic densities of the available devices have been relatively similar in size compared to the application. But with the modern FPGA expanding beyond 10 million system gates, and through the use of dynamic reconfiguration, it has become feasible for several applications to share a single high density device. / Thesis (PhD)--University of South Australia, 2005.

Bibliography : leaves 219-227 / xix, 227 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1993?

This thesis presents the design and development of a process to model Very Long Base Line Interferometry (VLBI) aperture synthesis antenna arrays. In line with the Auckland University of Technology (AUT) Institute for Radiophysics and Space Research (IRSR) aims to develop the knowledge, skills and experience within New Zealand, extensive use of existing radio astronomical software has been incorporated into the process namely AIPS (Astronomical Imaging Processing System), MIRIAD (a radio interferometry data reduction package) and DIFMAP (a program for synthesis imaging of visibility data from interferometer arrays of radio telescopes). This process has been used to model various antenna array configurations for two proposed New Zealand sites for antenna in a VLBI array configuration with existing Australian facilities and a passable antenna at Scott Base in Antarctica; and the results are presented in an attempt to demonstrate the improvement to be gained by joint trans-Tasman VLBI observation. It is hoped these results and process will assist the planning and placement of proposed New Zealand radio telescopes for cooperation with groups such as the Australian Long Baseline Array (LBA), others in the Pacific Rim and possibly globally; also potential future involvement of New Zealand with the SKA. The developed process has also been used to model a phased building schedule for the SKA in Australia and the addition of two antennas in New Zealand. This has been presented to the wider astronomical community via the Royal Astronomical Society of New Zealand Journal, and is summarized in this thesis with some additional material. A new measure of quality (“figure of merit”) for comparing the original model image and final CLEAN images by utilizing normalized 2-D cross correlation is evaluated as an alternative to the existing subjective visual operator image comparison undertaken to date by other groups. This new unit of measure is then used in the presentation of the results to provide a quantative comparison of the different array configurations modelled. Included in the process is the development of a new antenna array visibility program which was based on a Perl code script written by Prof Steven Tingay to plot antenna visibilities for the Australian Square Kilometre Array (SKA) proposal. This has been expanded and improved removing the hard coded fixed assumptions for the SKA configuration, providing a new useful and flexible program for the wider astronomical community. A prototype user interface using html/cgi/perl was developed for the process so that the underlying software packages can be served over the web to a user via an internet browser. This was used to demonstrate how easy it is to provide a friendlier interface compared to the existing cumbersome and difficult command line driven interfaces (although the command line can be retained for more experienced users).

Field programmable gate arrays are a class of integrated circuit that enable logic functions and interconnects to be programmed in almost real time. They can implement fine grained parallel computing architectures and algorithms in hardware that were previously the domain of custom VLSI. Field programmable gate arrays have shown themselves useful at exploiting concurrency in a range of applications such as text searching, image processing and encryption. When coupled with a microprocessor, which is more suited to computation involving complex control flow and non time critical requirements, they form a potentially versatile platform commonly known as a Reconfigurable Computer. Reconfigurable computing applications have traditionally had the exclusive use of the field programmable gate array, primarily because the logic densities of the available devices have been relatively similar in size compared to the application. But with the modern FPGA expanding beyond 10 million system gates, and through the use of dynamic reconfiguration, it has become feasible for several applications to share a single high density device. However, developing applications that share a device is difficult as the current design flow assumes the exclusive use of the FPGA resources. As a consequence, the designer must ensure that resources have been allocated for all possible combinations of loaded applications at design time. If the sequence of application loading and unloading is not known in advance, all resource allocation cannot be performed at design time because the availability of resources changes dynamically. The use of a runtime resource allocation environment modelled on a classical software operating system would allow the full benefits of dynamic reconfiguration on high density FPGAs to be realised. In addition to runtime resource allocation, other services provided by an operating system such as abstraction of I/O and inter-application communication would provide additional benefits to the users of a reconfigurable computer. This could possibly reduce the difficulty of application development and deployment. In this thesis, an operating system for reconfigurable computing that supports dynamically arriving applications is presented. This is achieved by firstly developing the abstractions with which designers implement their applications and a set of algorithm requirements that specify the resource allocation and logic partitioning services. By combining these, an architecture of an operating system for reconfigurable computing can be specified. A prototype implementation on one platform with multiple applications is then presented which enables an exploration of how the resource allocation algorithms interact amongst themselves and with typical applications. Results obtained from the prototype include the measurement of the performance loss in applications, and the time overheads introduced due to the use of the operating system. Comparisons are made with programmable logic applications run with and without the operating system. The results show that the overheads are reasonable given the current state of the technology of FPGAs. Formulas for predicting the user response time and application throughput based on the fragmentation of an FPGA are then derived. Weaknesses are highlighted in the current design flows and the architecture of current FPGAs must be rectified if an operating system is to become main-stream. For the tool flows this includes the ability to pre-place and pre-route cores and perform high speed runtime routing. For the FPGAs these include an optimised network, a memory management core, and a separate layer to handle dynamic routing of the network. / thesis (PhD)--University of South Australia, 2005.

Würzburg, Universiẗat, Diss., 2007.

Thesis (M.S.)--Ohio University, August, 1986. / Title from PDF t.p.

Diss. Uppsala : Univ., 2002.