Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 11 of 11 for “"Microvalves"”.
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Optimization and application of normally closed microvalves in microfluidics
… ease of fabrication and integration of pneumatic microvalves has enabled extensive miniaturization of microfluidic devices that are capable of performing massively parallel operations. These valves in their typical open configuration, also known as normally open (NO) valves, require to be actuated …
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Electrostatically Actuated Microvalves Fabricated with Soft-Lithographic Techniques for Integrated Microfluidics
… to guide the fabrication process of the microvalves and also optimize the electrical potentials needed to actuate the microvalves. Several methods were investigated for conferring conductivity to elastomeric membranes, including the patterning of nanoparticle/elastomer composites, the …
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Design, Fabrication, and Test of Chaotic Micromixers, Hydrogel Microvalves and pH Regulation Systems
In the last part of the thesis, two integrated microsystems designed to provide self regulation of pH in bioassays are demonstrated. The first system is based on the counterflow microdialysis principle, whereas the second system involves direct addition of an acidic or basic buffer solution into a …
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Reduction of Unsteady Stator-Rotor Interaction by Trailing Edge Blowing Using MEMS Based Microvalves
This research performs an experimental study of a trailing edge blowing system that can adapt to variations in flow parameters and reduce the unsteady stator-rotor interaction at all engine operating conditions. The fan rotor of a 1/14 scale turbofan propulsion simulator is subjected to spatially …
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Electrostatic actuators for portable microfluidic systems
… Others have attempted to modify pneumatic microvalves for portable applications, e.g., by transitioning to electromagnetic, thermopneumatic, or piezoelectric actuation principles. However, none of these strategies maintain the proper balance of simplicity, functionality, and ease of …
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Characterization and systems integration of microreactors
… of the reactor devices straightforward. Shut-off microvalves and proportional microvalves from Redwood Microsystems, with their control electronics, have also been mounted on PC boards to control the gas flow in the system. This allows the entire system: reactors, device electronics, and gas …
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Fabrication, Characterization, and Transport Analysis of Silicon-Based Microsystems: Micro Fuel Cells and Micro Gas Perconcentrators
… desorption. Integration with electrostatic microvalves enabled the muGPC to achieve extremely small dead volumes and fast injection times while the power and energy required to run a microheater, a key component of the muGPC, were kept small. Another unique feature of the muGPC is the use of …
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Design, modeling, fabrication and testing of a piezoelectric microvalve for high pressure, high frequency hydraulic applications
… that had not previously been satisfied by other microvalves presented in the literature. This research was carried out through a series of modeling, design, fabrication, assembly, and experimental testing tasks. Linear and non-linear modeling tools characterizing the structural deformations of …
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Development of hydraulic propulsion for colonoscopic devices
… options, including manoeuvring using on-board microvalves. A hydro-jet colonoscope system was constructed and tested in a synthetic human colon model. Results indicated that the hydro-jet colonoscope could navigate through various colonic layouts quickly and safely, suggesting that further …
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Elemental speciation and miniaturised sample introduction studies for inductively coupled plasma mass spectrometry
… small ionic species are discussed. The use of microvalves formed in situ within the microchip channels is investigated. Photo-polymerisation with a UV laser source is performed to produce rigid (highly cross-linked), non-stick (highly fluorinated) monoliths which do not adhere to the glass …
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Uv-liga Compatible Electroformed Nano-structured Materials For Micro Mechanical Systems
… large flow rates (>10 cc/s). The fabricated microvalves weigh 0.2 gram, after packing with a novel designated valve stopper. The tested results showed that the micro valve was able to operate at up to 14kHz. This is a great difference in comparison to traditional mechanical valves whose …