John Robert Waldeisen

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In this work, we report the design, fabrication, and characterization of a tunable optofluidic microlens that focuses light within a microfluidic device. The microlens is generated by the interface of two co-injected miscible fluids of different refractive indices, a 5 M CaCl(2) solution (n(D) = 1.445) and deionized (DI) water (n(D) = 1.335). When the(More)
Micro- and nanoscale engineering approaches in medicine have the potential to recreate physiologically relevant stem cell microenvironments to enhance our understanding of stem cell behaviour and bring stem cell therapy closer to fruition. The realization of such advancements will impact a number of therapeutic applications, the most immediate of which may(More)
Current molecular diagnostic techniques for susceptibility testing of septicemia rely on genotyping for the presence of known resistance cassettes. This technique is intrinsically vulnerable due to the inability to detect newly emergent resistance genes. Traditional phenotypic susceptibility testing has always been a superior method to assay for resistance;(More)
The disassembly of a core-satellite nanostructured substrate is presented as a colorimetric biosensor observable under dark-field illumination. The fabrication method described herein utilizes thiol-mediated adsorption and streptavidin-biotin binding to self-assemble core-satellite nanostructures with a sacrificial linking peptide. Biosensing functionality(More)
This paper demonstrates a label-free biological sensing method usmg nanoporous polymer gratings. The high index modulation (0.07) of the nanoporous polymer grating structure generates a high signal-to-noise ratio, making the structure an ideal label-free biodetection platform. The fabrication process of the nanoporous polymeric grating involves holographic(More)
Cell ‘trap and release’ in microfluidic devices is critical for on-chip concentration purposes and dynamic microarrays. However, most existing mechanical trapping modalities lack release capabilities and some employ very complex or abrasive trapping mechanisms. Here we describe a novel cell ‘trap and release’ device, which employs principles similar to the(More)
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