Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Engineering (5)
- Mechanical Engineering (2)
- Polymer Chemistry (2)
- Analytical, Diagnostic and Therapeutic Techniques and Equipment (1)
- Biological and Chemical Physics (1)
-
- Biomedical Devices and Instrumentation (1)
- Biomedical Engineering and Bioengineering (1)
- Chemical Engineering (1)
- Complex Fluids (1)
- Computer-Aided Engineering and Design (1)
- Diagnosis (1)
- Electrical and Computer Engineering (1)
- Electrical and Electronics (1)
- Equipment and Supplies (1)
- Fluid Dynamics (1)
- Materials Science and Engineering (1)
- Medicine and Health Sciences (1)
- Other Analytical, Diagnostic and Therapeutic Techniques and Equipment (1)
- Physical Chemistry (1)
- Physics (1)
- Institution
- Publication Year
- Publication
- Publication Type
Articles 1 - 15 of 15
Full-Text Articles in Analytical Chemistry
Impact Of Y-Mixer Geometry And Flow Rate Modulation On Chemical Gradient Generators In Microfluidic Devices, Elizabeth Thurston Hutton
Impact Of Y-Mixer Geometry And Flow Rate Modulation On Chemical Gradient Generators In Microfluidic Devices, Elizabeth Thurston Hutton
College of Graduate Studies: Theses & Dissertations
Various microfluidic structures are devised to generate tunable, stable spatiotemporal chemical gradients for single-cell studies. This work addresses the role of Y-mixer junctions in generating nonlinear gradients by increasing the width of one arm (bias), which is suspected to cause premature diffusion within the mixer. This study introduced a cinching feature to narrow the wider arm locally and redefine the junctions of these biased Y-mixers using four novel geometries defined by a 5-micrometer drawing rule. Furthermore, three flow rate factors allowed us to explore the impact on the generated gradient landscapes. The results showed that the four novel designs similarly …
Development Of Lab-On-A-Chip Platforms Incorporating A Novel Acoustic Atomization Induced Pump Based On A Vibrating Sharp Edge Capillary., Balapuwaduge Lihini Tharanga Catherine Mendis
Development Of Lab-On-A-Chip Platforms Incorporating A Novel Acoustic Atomization Induced Pump Based On A Vibrating Sharp Edge Capillary., Balapuwaduge Lihini Tharanga Catherine Mendis
Graduate Theses, Dissertations, and Problem Reports (ETD)
Capillary Vibrating Sharp-edge Ionization device (cVSSI device) was developed by our laboratory with a low cost and an easy fabrication procedure. The generation of small liquid droplets by this technique has been used as an ionization source for mass spectrometry analysis platforms. On usual applications incorporating the cVSSI device a syringe pump was connected to the back end of the vibrating sharp tip capillary to ensure continuous loading of sample into the capillary to sustain the ionization process at the tip end of the vibrating sharp tip capillary. We were able to observe that upon the generation of droplets the …
Low-Cost Microstereolithography 3d Printing With Microfluidic Microsampling Applications, Lauren Twombly
Low-Cost Microstereolithography 3d Printing With Microfluidic Microsampling Applications, Lauren Twombly
Chemistry & Biochemistry Undergraduate Honors Theses
The growing field of stereolithography 3D printing has welcomed a new age ofmicrofluidic device fabrication techniques. When compared to previous planar fabrication techniques such as soft-lithography, stereolithography 3D printing offers highly automated procedures, reduced fabrication times, and greater complexity of device features. To date, the greatest tradeoff for 3D printing in microfluidic device fabrication is poorer resolution when compared to soft-lithography which can produce feature sizes on the nanometer scale. The poorer resolution of 3D printing limits the feasible size of features. While highly sophisticated 3D printers are capable of achieving sub 10 μm resolution, these instruments are incredibly expensive …
Development Of Novel Mass Spectrometry Method For The Analysis Of Complex Compounds, Jing Wang
Development Of Novel Mass Spectrometry Method For The Analysis Of Complex Compounds, Jing Wang
Graduate Theses, Dissertations, and Problem Reports (ETD)
As mass spectrometry methods continue to advance, there is a growing need for innovative interfaces that can seamlessly integrate sample pretreatment, separation, and ionization, allowing for direct mass analysis while maintaining a simple and flexible system. The evolution of ambient ionization techniques has made it feasible to nebulize analyte compounds at ambient pressure. Moreover, single-cell proteomics using mass spectrometry is gaining increasing attention, necessitating the development of precise sample preparation techniques to enhance sensitivity. In this dissertation, I demonstrate the novel mass spectrometry system to couple the sample pretreatment with the direct mass spectrometry detection for the analysis of diverse …
Microfluidic Thermal Gel Electrophoresis For Native Protein Analysis, Shakila Hasanthika Peli Thanthri
Microfluidic Thermal Gel Electrophoresis For Native Protein Analysis, Shakila Hasanthika Peli Thanthri
Wayne State University Dissertations
Proteins must be in their native states to carry out their intended biological functions. Native protein structure requires that proteins be folded into the correct conformations and possess the necessary post-translational modifications (PTMs). These higher-order structures are critical to ensuring that proteins are biologically active and properly interact with neighboring molecules. However, assessing folding conformations and modified protein variants is challenging, and routine sample validation techniques like polyacrylamide gel electrophoresis (PAGE) are not capable of analyzing higher-order structures. Gradient PAGE gels can determine the molecular weight of proteins over a wide mass range, but protein separation resolutions are poor because …
Harnessing Acoustic Streaming For Bioanalysis In Microfluidics, Xiaojun Li
Harnessing Acoustic Streaming For Bioanalysis In Microfluidics, Xiaojun Li
Graduate Theses, Dissertations, and Problem Reports (ETD)
In the past few decades, microfluidic technology has been developed rapidly in both fabrication methods and multifunctionality integrations, making it a powerful tool for a wider variety of biological applications. The device fabrication method has expanded from conventional polymer-based micro devices to 3D-printed micro devices, and allows multiple functions such as electric, optic, magnetic and acoustic to be integrated on a single platform. This dissertation focuses on method development of acoustic streaming-based microfluidics in bioanalysis such as immunoassay, enzyme kinetics and DNA fragmentation analysis. In this dissertation, a micromixer was developed based on acoustic streaming generated from sharp-edge structure vibration …
Modification And Optimization Of Conducting Polymer-Modified, Redox-Magnetohydrodynamics (R-Mhd) Pumping For Enhanced And Sustained Microfluidics Applications, Md Foysal Zahid Khan
Modification And Optimization Of Conducting Polymer-Modified, Redox-Magnetohydrodynamics (R-Mhd) Pumping For Enhanced And Sustained Microfluidics Applications, Md Foysal Zahid Khan
Graduate Theses and Dissertations
In this work, a novel microfluidic pumping approach, redox-magnetohydrodynamics (R-MHD) has improved by materials and device optimization to use in lab-on-a-chip applications. In R-MHD, magnetic flux (B) and ionic current density (j) interacts to generate body force (FB) in between active electrodes, according to the equation FB = j×B. This unique fluid pumping approach is scalable, tunable, generates flat flow profile, and does not require any channels or valves. Pumping performance, such as speed scales with the ionic current density (j) and duration depends on the total charge (Q). The ionic current density (j) results from the conversion of electronic …
Development Of Microdialysis Probes In Series Approach Toward Eliminating Microdialysis Sampling Calibration: Miniaturization Into A Pdms Microfluidic Device, Randy Espinal Cabrera
Development Of Microdialysis Probes In Series Approach Toward Eliminating Microdialysis Sampling Calibration: Miniaturization Into A Pdms Microfluidic Device, Randy Espinal Cabrera
Graduate Theses and Dissertations
A new microdialysis sampling method and microfluidic device were developed in vitro. The method consisted of using up to four microdialysis sampling probes connected in series to evaluate the relative recovery (RR) of different model solutes methyl orange, fluorescein isothiocyanate (FITC)-dextran average mol. wt. 4,000 (FITC-4), FITC-10, FITC-20, and FITC-40. Different flow rates (0.8, 1.0, and 1.5 µL/min) were used to compare experimentally observed relative recoveries with theoretical estimations. With increasing the number of probes in series, the relative recovery increases and ~100% (99.7% ± 0.9%) relative recovery for methyl orange was obtained. For larger molecules such as fluorescein isothiocyanate …
Evaluation Of 5 Μm Superficially Porous Particles For Capillary And Microfluidic Lc Columns, James Grinias, Robert T. Kennedy
Evaluation Of 5 Μm Superficially Porous Particles For Capillary And Microfluidic Lc Columns, James Grinias, Robert T. Kennedy
College of Science & Mathematics Departmental Research
Large-size (4–5 µm) superficially porous particles yield lower plate heights (e.g., the minimal reduced plate height or hmin ≈ 1.5) than fully porous particles of a similar size when packed into large-bore columns. This property allows for better chromatographic performance without the higher pressures required for smaller particles. This study explores the use of such particles in microfluidic LC columns where materials and fitting pressure limits can constrain the size of particle used. The theoretically predicted performance improvements compared to fully porous particles were not demonstrated in capillary columns (with hmin ≈ 2 for both particle types), in …
Fundamental Studies Of Magnetoconvective Forces And Density Gradients In A Microfluidic Environment, Adam James Kreidermacher
Fundamental Studies Of Magnetoconvective Forces And Density Gradients In A Microfluidic Environment, Adam James Kreidermacher
Graduate Theses and Dissertations
Magnetoconvection is a promising phenomenon for developing new electrochemical-based microfluidic flow devices with unique capabilities, such as easily switching flow direction and adjusting flow speeds and flow patterns as well as avoiding bubble formation. In order to develop these devices it is necessary to study the underlying forces. Four contributions toward fluid flow were considered. The first and foremost is the magnetohydrodynamic force, which is the magnetic component of the Lorentz force and governed by the right hand rule. It generates the majority of the convention, and is the most well-known. The second is the gravitational force, which causes convection …
Modified-Electrodes For Redox-Magnetohydrodynamic (Mhd) Pumping For Microfluidic Applications, Christena Kayl Nash
Modified-Electrodes For Redox-Magnetohydrodynamic (Mhd) Pumping For Microfluidic Applications, Christena Kayl Nash
Graduate Theses and Dissertations
A new microfluidic pumping and stirring technique was demonstrated for lab-on-a-chip applications. Microfluidics was accomplished via redox-MHD, which takes advantage of a body force (FB) that is generated when there is a net movement of ions in solution (j) in the presence of a perpendicular magnetic field (B), according to the equation FB = j×B. In this work the movement of ions in solution was generated using electrodes modified with the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) rather than a redox species in solution, which can interfere with analyte detection and with biological species. …
Microfluidics Guided By Redox-Magnetohydrodynamics (Mhd) For Lab-On-A-Chip Applications, Vishal Sahore
Microfluidics Guided By Redox-Magnetohydrodynamics (Mhd) For Lab-On-A-Chip Applications, Vishal Sahore
Graduate Theses and Dissertations
Unique microfluidic control actuated by simply turning off and on microfabricated electrodes in a small-volume system was investigated for lab-on-a-chip applications. This was accomplished using a relatively new pumping technique of redox-magnetohydrodynamics (MHD), which as shown in this dissertation generated the important microfluidic features of flat flow profile and fluid circulation. MHD is driven by the body force, FB = j × B, which is the magnetic part of the Lorentz force equation, and its direction is given by the right hand rule. The ionic current density, j, was generated in an equimolar solution of potassium ferri/ferro cyanide by applying …
Integrated Approach For Low-Cost And Sensitive Multiplex Pathogen Detection On 3d Paper-Based Microfluidic Devices, Alejandra Valadez, Huan Hu, Xiujun James Li
Integrated Approach For Low-Cost And Sensitive Multiplex Pathogen Detection On 3d Paper-Based Microfluidic Devices, Alejandra Valadez, Huan Hu, Xiujun James Li
COURI Symposium Abstracts, Summer 2012
Recently, pathogenic microorganisms have aroused wide public concern for their potential to cause serious diseases in humans, animals and agricultural crops. Although DNA microarrays are commonly used for pathogen detection, the approach is sophisticated, time-consuming and requires expensive equipment, limiting its application in resource-poor settings. Herein we present a novel, low-cost, paper-based microfluidic approach for multiplexed DNA detection of Giardia Lamblia, S. aureus, and Entamoeba, by “on-chip” isothermal DNA amplification and hybridization. Paper-based microfluidics offers a novel, sensitive and low-cost alternative for Point-of-Care Diagnostics for the Developing Countries. The project described utilizes Loop-mediated Isothermal Amplification (LAMP), a novel isothermal DNA …
Factors Affecting Redox Magnetohydrodynamics For Flow In Small Volumes, Matthew D. Gerner
Factors Affecting Redox Magnetohydrodynamics For Flow In Small Volumes, Matthew D. Gerner
Graduate Theses and Dissertations
Lab-on-a-chip technologies offer the possibility of developing analytical devices that are low-cost, portable, disposable, fast, and operable by non-technical personnel. Such devices require automated methods to manipulate ultra-small volumes (picoliters) of samples and solution, including pumping, stirring, and positioning. Current methods for ultra-small volume microfluidics have limitations that restrict their use including high voltage requirements, disadvantageous flow profiles or rates, and relatively complicated fabrication due to mechanical parts. Redox magnetohydrodyanmics (RMHD) that utilizes permanent magnets for portability shows promise as a micropump with ease of switching flow direction, no moving parts, compatibility with both aqueous and non-aqueous solutions, low voltages …
Wearable Electrochemical Sensors For Monitoring Performance Athletes, Kevin J. Fraser, Vincenzo F. Curtin, Shirley Coyle, Benjamin Schazmann, Robert Byrne, Fernando Benito-Lopez, Roisin M. Owens, George C. Malliaras, Dermot Diamond
Wearable Electrochemical Sensors For Monitoring Performance Athletes, Kevin J. Fraser, Vincenzo F. Curtin, Shirley Coyle, Benjamin Schazmann, Robert Byrne, Fernando Benito-Lopez, Roisin M. Owens, George C. Malliaras, Dermot Diamond
Conference Papers
Nowadays, wearable sensors such as heart rate monitors and pedometers are in common use. The use of wearable systems such as these for personalized exercise regimes for health and rehabilitation is particularly interesting. In particular, the true potential of wearable chemical sensors, which for the real-time ambulatory monitoring of bodily fluids such as tears, sweat, urine and blood has not been realized. Here we present a brief introduction into the fields of ionogels and organic electrochemical transistors, and in particular, the concept of an OECT transistor incorporated into a sticking-plaster, along with a printable “ionogel” to provide a wearable biosensor …