Publications by authors named "Thomas W Haas"

We present a real-rock micromodel approach whereby microfluidic channels are fabricated in a naturally occurring mineral substrate. The method is applied to quantify calcite dissolution which is relevant to oil/gas recovery, CO2 sequestration, and wastewater disposal in carbonate formations - ubiquitous worldwide. The key advantage of this method is the inclusion of both the relevant substrate chemistry (not possible with conventional microfluidics) and real-time pore-scale resolution (not possible with core samples).

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We present a lab-on-a-chip approach to informing thermal oil recovery processes. Bitumen - a major global resource - is an extremely viscous oil which is extracted by injecting steam underground in a process known as Steam Assisted Gravity Drainage (SAGD). Here, a microfluidic network saturated with bitumen provides a physical model of the SAGD reservoir; steam is injected into the chip, and the oil recovery dynamics are visualized and quantified in real-time.

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We characterize layered, delamination resistant, tissue engineering scaffolds produced by gradient electrospinning using computational fluid dynamics, measurements of fiber diameter with respect to dynamic changes in polymer concentration, SEM analysis, and materials testing. Gradient electrospinning delivers a continuously variable concentration of polymer to the electrospinning jet, resulting in scaffolds that exhibit controlled transitions in fiber diameter across the Z-axis. This makes it possible to produce scaffolds that exhibit very different fiber sizes and material properties on opposing surfaces while eliminating the boundary layers that lead to delamination failures.

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We present Teflon-based microfluidic chips fabricated by laminating multiple layers of laser-cut Teflon film. In addition to being solvent-resistant, these chips enable simple multilayer fabrication, have uniform rectangular cross-section and are sufficiently thin to (1) reduce cost, (2) enable rapid temperature control, and (3) provide optical transparency. The chips can be fabricated without a cleanroom from start to finish in less than 2 h.

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