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Optically Clear Biomicroviscometer with Modular Geometry Using Disposable PDMS ChipsLee-Yow, Niko January 2018 (has links)
We have designed and fabricated a biomicroviscometer platform for measurement of microflows of biological fluids. The biomicroviscometer combines an optically clear biocompatible polydimethylsiloxane (PDMS) channel with on-chip integrated microfluidic differential pressure sensors and capabilities of modular channel geometries. This setup allows for a direct measurement of the change in pressure and flow rate, increasing the overall accuracy of the measurement of viscosity and optical observation. We present an introduction of this combined method of measurement with different channel dimensions, using Newtonian and non Newtonian fluids, and the corresponding calculations. This measurement technique has potential applications in measuring rheological properties at the micro level to further blood disease analysis, and lab-on-a-chip fabrication and analysis.
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Reduced Susceptibility Of Deformation Due To Vibrational And Gravitational Effects On A Focus Variable Adaptive LensRelina, Victoriya 01 January 2013 (has links)
Orthodox optical devices, such as lenses, mirrors, and prisms, are composed of solidstate materials, which although well studied and implemented ubiquitously are severely limited in their adaptable properties. An arguably new field of adaptive optics has emerged to further expand photonic manipulation competences of optical components. Fluid-based adaptive optical components were introduced as early as 1968 [1]; such components have the ability to change the shape of their interface surface, thus allowing for a variable curvature profile. The method of manipulation varies greatly, as does the range of surface deformations. A solid-state optical component is affected by system vibration variation only (difference in vibration from one component to the other due to damping effect). By comparison, two large limiting factors of a fluid-based adaptive optical component are the effect of local vibrations on the surface of the device and gravitational effect (when the optical axis of a lens is positioned parallel to gravitational pull). Such a gravitational effect has been mitigated by the invention of the mechanical electrowetting lens [2], which uses density matching of two liquids that make up an adaptive lens. However, this configuration creates an extra limiting factor of density matching two optically clear fluids with a desirable transmission spectrum. This method can also become bulky when a large aperture is needed. In this thesis, two adaptive lens systems are explored. Principles of operation, performance, limitations, as well as future improvements are studied and theorized. iv The first lens uses an optically clear elastomer as the substrate of an adaptive lens and a primitive mechanical manipulation to turn a plano–plano lens into a plano–convex lens. The second lens is composed of an optically clear gel rather than a fluid. Both methods exhibit excellent optical properties regardless of the orientation about the gravitational pull and significantly limit local vibration affects simply by the physical nature of the chosen materials.
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Developing Microfluidic Devices for Biomolecule AnalysisNielsen, Jacob Brent 22 June 2023 (has links) (PDF)
Microfluidics can take laboratory processes and miniaturize them, which led to the term lab-on-a-chip. Microfluidic devices are fabricated with a variety of materials and methods, each offering distinct advantages for bioanalysis. This dissertation describes two methods to create these devices, with the use of four different materials to achieve different assay needs. In the first application in this dissertation, hot-embossed cyclic olefin copolymer was used to create microdevices to electrophoretically separate seven preterm birth biomarkers. One biomarker, thrombin-antithrombin III, cannot be purchased commercially so I developed methods for its assembly in the lab. Dot blots and mass spectrometry were used to evaluate the synthesis of thrombin-antithrombin III. The next application evaluated digital-light processing stereolithography 3D printing resins. A new optically clear resin was developed and compared to two previously described resins. The physical characteristics (i.e., hardness and Young's modulus), biocompatibility, and electrophoretic separation capabilities were compared. Lastly, 3D printing was used to create microfluidic devices with embedded affinity columns to extract, fluorescently label, and detect chikungunya virus RNA. Conditions for detecting RNA were optimized using oligonucleotides, and a linear relationship was determined for concentration of RNA loaded and fluorescent signal detected. The specificity of the column was tested with a genetically similar virus; viral RNA from both viruses was loaded to demonstrate ability to extract and detect only chikungunya virus. These applications show microfluidic devices' ability to analyze various biomolecules. This work also exhibits multiple tools that can be used in microfluidics. Using these methods provides better characterization of diseases, drugs, and wellness.
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