Dorian Liepmann (Advisor)

Research Advised by Professor Dorian Liepmann

DL15/APP: A planar micropump utilizing thermopneumatic actuation and in-plane flap valves

Stefan Zimmermann
Jeremy Frank

Development of a planar micropump for integration in a planar microfluidic mixer.

Project end date: 08/18/04

DL10: Clinical Testing of MEMS-Syringes

Raja Sivamani
Boris Stoeber

MEMS syringes offer possibilities of painlessly injecting suspensions of fine drug powders and biocompatible liquids through an array of hollow microneedles into the epidermis under the stratum corneum. The stratum corneum serves as the main barrier to transdermal penetration and drug delivery. It is important to find microneedle design parameters that will maximize skin penetration and delivery of drugs into the epidermal skin layer. Eventually, microneedles may be adapted for medical injection applications such as diabetes treatment and vaccines.

Project end date:...

APP63: Sickle-Cell Anemia Event Detection Sensor

Jennifer S. Wade

The objective of this project is to design, fabricate and test a micro-flow channel that can be used to accurately simulate, detect, analyze and predict the rheological properties of Sickle Cells flowing through arteriole bifurcations of various diameters and lengths. One property of interest is the effect blood osmolarity variations has on Hb SS red cell compliance, as well as, the variation of hematocrit levels. Ultimately, this data and the trends extrapolated from it will be used to understand the differences between healthy and Sickle blood flow in arterioles. As well as,...

DL11: Microflow Control using Thermally Responsive Triblock Copolymers

Boris Stoeber

Dilute aqueous solutions of poly(ethylene oxide)x-poly(propylene oxide)y-poly(ethylene oxide)x triblock copolymers undergo reversible gel formation at elevated temperatures. This effect can be effectively used for active and passive flow control in microfluidic devices, where the gel phase can block the flow channel partially or entirely. Heat transfer occurs fast through the typically small width of a microchannel resulting in a fast valve response time. A novel micromixing concept has been developed based on active microvalves.

Project end date: 08/31/05

LPL36: Behavior of water and ice in nanocavities

J. Tanner Nevill

Nanogap sensors have been developed to study various biochemical reactions such as DNA hybridization, protein conformation, and polymer formation. Recently, the nanogap sensors have been used to study the dielectric properties of water and ice. It is well known that water plays a vital role in many processes on the molecular level. Without water, there would be no cell membranes, no ion transport, no protein ligand interaction, and the list can go on ad nauseum. Although we recognize how important water is to these functions, the precise role of water is still not completely...

BPN327: Plastic Microsyringe

Kathleen Fischer

Stem cells hold the promise of producing functional tissues which can replace those lost due to disease or injury. New organ tissues, such as those found in the heart, liver, or nervous system, can be created from pluripotent stem cells through the process of differentiation. Additionally, pluripotent stem cells can produce an unlimited supply of new stem cells in a process called "self-renewal". In culture, pluripotent stem cells form isolated colonies, and the geometry of these colonies can have a profound impact on their capacity for differentiation. Current culture techniques...

BPN325: Microfluidic Device for Measuring Endothelial Permeability

Peter White

Both in vitro and in vivo studies have shown that the permeability of the endothelial cell layer that lines vascular walls is influenced by hemodynamic forces. Specific wall shear stress patterns are believed to induce phenotypic changes in cells that alter the uptake of molecules such as low-density lipoprotein (LDL) and lead to the development of atherosclerotic lesions. The purpose of this research is to develop a microfluidic device in which the flux of specific macromolecules across an endothelial layer can be measured in different locations of a channel. By appropriately...

DL5: DNA Transport in Microfluidic Systems

Shelly Gulati

Fully integrated lab-on-a-chip systems for applications such as DNA sequencing and pathogen detection will incorporate significant microfluidic components. These systems will necessarily require the flow of large molecules such as DNA, which give the bulk fluid viscoelastic behavior. Additionally, the characteristic lengths of these molecules will approach those of the fluid channel, presenting a unique flow situation that is not well understood. The effects of microscale flow in canonical microfluidic structures on the conformation of DNA, and the reciprocal effects of DNA...

BPN387: Modeling of Temperature Effects on Piezoresistor Sensitivity

Zachary Lee

Joule heating occurs in any conductor when current passes through it due to the resistance of the conductor. Semiconductor strain gauges in particular are very susceptible to such temperature changes as they can cause significant fluctuations in the resistance of the gauge itself. This is generally referred to as self-heating of the strain gauge. Self-heating effects are undesirable as they can drastically decrease the signal-to-noise ratio of the strain gauges. In order to improve the sensitivity of a strain gauge it is of interest to characterize the thermal effects of the current...

BPN401: Microjets for Single Cell Injections

Peter F.White

The goal of this project is to develop a microfluidic system that uses a high speed micron sized jet to inject biological material into single cells in a highly controlled fashion.

Project end date: 01/29/08