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Full-Text Articles in Engineering
Engineered Material Systems For Mimicking Tissue And Disease, Margrethe Ruding
Engineered Material Systems For Mimicking Tissue And Disease, Margrethe Ruding
McKelvey School of Engineering Theses & Dissertations
This thesis comprises two studies involving design and application of soft material systems. The goal of the first study was to design, fabricate, and characterize hydrogel lattice structures with consistent, controllable, anisotropic mechanical properties. Lattices, based on four types of unit cells (cubic, diamond, vintile, and Weaire-Phelan), were printed using stereolithography (SLA) of polyethylene glycol diacrylate (PEGDA). In order to create structural anisotropy in the lattices, unit cell design files were scaled in one direction by a factor of two in each layer and then printed. The mechanical properties of the scaled lattices were measured in shear and compression and …
Investigation Of Microdroplet Generation, Morphological Evolution, And Applications Under Quasi-Steady And Dynamic States, Li Shan
McKelvey School of Engineering Theses & Dissertations
Microscale droplets are commonly encountered in the fields of materials processing, thermal fluids, and biology. While these droplets are naturally occurring, recent advances in microfabrication have enabled researchers to harness their enhanced transport characteristics for numerous laboratory and industrial applications from controlled chemical synthesis to inkjet printing and thermal management. Smaller droplets have larger specific surface area and a greater perimeter-to-area ratio when resting on a surface (i.e., sessile), which accelerates processes occurring at droplet surfaces like evaporation, chemical reaction, or combustion. The demand for microdroplets with smaller and more uniform sizes has motivated investigation of how such droplets can …
Understanding The Interactions Between Acoustic Fields And Motile Microorganisms In Microfluidic Systems, Minji Kim
McKelvey School of Engineering Theses & Dissertations
Acoustofluidics utilizes ultrasonic standing waves in microscale fluidic channels to manipulate cells, microorganisms, and other objects sized from tens of nanometers to tens of microns. When exposed to an ultrasonic standing wave field, particles suspended in a fluid become confined to potential minima (nodes) of the acoustic field. I will present a number of related studies that involve the interactions between acoustic fields and motile microorganisms. First, I will show how an acoustic trap-and-release method enables rapid quantification of cell motility. As a demonstration, the newly developed motility assay is applied to discriminate swimming of wild-type and mutant Chlamydomonas reinhardtii …
Longitudinal Acoustic Traps: Design, Fabrication, And Evaluation For Biological Applications, Michael Moore Binkley
Longitudinal Acoustic Traps: Design, Fabrication, And Evaluation For Biological Applications, Michael Moore Binkley
McKelvey School of Engineering Theses & Dissertations
Acoustofluidics combine ultrasonic actuation with small-volume microfluidic channels to enable precise, contactless object manipulation for a range of applications from serial chemical processing to blood component separation and single-cell analysis. Micron- to millimeter-scale vibrational waves generate reproducible pressure fields within the microfluidic channels and chambers. By exploiting the material property mismatch between a particle (polymeric and silica beads, cells, etc.) and a suspending fluid, the acoustic radiation force is used to move particles toward regions of low (nodes) or high pressure (antinodes). An understanding of these field-particle interactions is applied to design and implement complicated channel architectures for preferential segregation …
Particle Enrichment In Longitudinal Standing Bulk Acoustic Wave Microfluidics, Mingyang Cui
Particle Enrichment In Longitudinal Standing Bulk Acoustic Wave Microfluidics, Mingyang Cui
McKelvey School of Engineering Theses & Dissertations
Separation, isolation, and enrichment of targeted nano- and microparticles are critical to a variety of biomedical applications from clinical research (development of therapeutics and diagnostics) to fundamental investigations that require concentration of specific cells from culture, separation of target species from heterogenous mixtures, or controlled perturbation of cells and microorganisms to determine their response to stimuli. Numerous techniques are available for bench-scale and medical settings; however, these traditional approaches are often labor intensive, time-consuming, costly, and/or require modification of the target. Efficiency and specificity are also lacking. Recently, techniques that exploit the similar scales of microfluidic technologies and the intrinsic …