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Full-Text Articles in Engineering

Characterization Of Pressure Driven And Electro-Kinetically Driven Flow In A Micro-Fluidic Chip Using Particle Imaging Velocimetry, Alexis Paige Weckel Jun 2014

Characterization Of Pressure Driven And Electro-Kinetically Driven Flow In A Micro-Fluidic Chip Using Particle Imaging Velocimetry, Alexis Paige Weckel

Materials Engineering

The goal of this research is to compare electro-kinetic and pressure driven flow rates and velocity profiles (near wall vs. middle) in a microfluidic chip made of PDMS using particle imaging velocimetry (PIV) of an aqueous solution of fluorescent polystyrene (PS) particles using a laser confocal microscope (LCM). Microfluidic channels were fabricated out of PDMS using a SU-8 mold to be 25mm long and 180um by 1000um. Pressure-driven data did not show the expected parabolic profile because of the large width to depth ratio. In addition, data showed a calculated average significantly higher than the projected particle velocity through the …


Development Of A High Precision Quantum Dot Synthysis Method Utilizing A Microfluidic Reactor And In-Line Fluorescence Cell, Harry Lafferty, Jonny Hoadley Jun 2013

Development Of A High Precision Quantum Dot Synthysis Method Utilizing A Microfluidic Reactor And In-Line Fluorescence Cell, Harry Lafferty, Jonny Hoadley

Materials Engineering

Quantum dots show great potential for use as spectral converters in solar cells, lighting applications and biological imaging. These applications require precise control of quantum dot size to maximize performance. The fluorescence profile of quantum dots in solution correlates directly with particle size. An alternative, high precision process was developed for the synthesis of cadmium-selenide quantum dots using a microfluidic reactor and fluorescence flow through cell. The process required creating separate cadmium and selenium precursors that were then mixed in a nitrogen environment at 17± 1°C. Using an NE-300® syringe pump, the solution was pumped through a microfluidic reactor …


The Design And Manufacture Of A Microfluidic Reactor For Synthesis Of Cadmium Selenide Quantum Dots Using Silicon And Glass Substrates, Peter Gonsalves Jun 2011

The Design And Manufacture Of A Microfluidic Reactor For Synthesis Of Cadmium Selenide Quantum Dots Using Silicon And Glass Substrates, Peter Gonsalves

Materials Engineering

A microfluidic reactor for synthesizing cadmium selenide (CdSe) quantum dots (QDs) was synthesized out of silicon and Pyrex glass. Microfabrication techniques were used to etch the channels into the silicon wafer. Holes were wet-drilled into Pyrex glass using a diamond-tip drill bit. The Pyrex wafer was aligned to the etched silicon wafer and both were anodically bonded to complete the microfluidic reactor. Conditions for anodic bonding were created by exposing the stacked substrates to 300V at ~350oC under 5.46N of force. Bulk CdSe solution was mixed at room temperature and treated as a single injection. The syringe containing …


Characterization Of A Pdms Microfluidic Reactor For Synthesizing Quantum Dots, Brian Harley Jun 2011

Characterization Of A Pdms Microfluidic Reactor For Synthesizing Quantum Dots, Brian Harley

Materials Engineering

A PDMS microfluidic reactor was made in Cal Poly’s class 1000 clean room for the purpose of synthesizing quantum dots. The device master mold was made from a silicon substrate and SU-8 features 50μm tall. The PDMS reactor was cast from that mold. The flow rates of fluid through the channels, heating of the reactor and pressure in the reactor were measured in order to characterize the potential for synthesizing quantum dots. Flow rates of 20 mL/hr through 4 mL/hr were tested to characterize the consistency of amount of time the fluid remains in the reactor at a constant flow …