Nano- and Microfluidics

Group: WVU: Timperman (Chemistry), Edwards (Physics).

Research Experiences: Modeling and prediction of micro and nanofluidic behavior, characterization and imaging of microfluidic channels.

Integrated recognition systems will contain functional nanoscale elements that are not independent systems. Microfluidic systems serve as a link between real world samples and nanoscale detection elements, such as quantum dots or cantilevers. One advantage of microfluidic systems is the reduced size of their channels, which are smaller than a human hair in diameter, make them great for handling small volume samples, or samples with a small amount of the compound of interest. Micro- and nanofluidic systems can incorporate functions, such as sample collection, dispensing, modification, separations, and detection with the nanoscale element(s), which can link macro with nanoscale devices. Microfluidic systems are used for the manipulation and transport of samples or reagents on the order of a nanoliter in volume. Nanoscale elements can be easily incorporated into the micro- and nanofluidic channels whose width and depth range from a few hundred microns down to a few nanometers in width and depth.

At WVU microfluidic devices are being developed for the analysis of proteins from blood and cell lysates. Improved detection of proteins from blood samples will improve disease diagnosis, while cell lysates can be compared to determine what goes wrong when healthy cells become diseased. The microfluidic systems are coupled directly with the mass spectrometer, which identifies or determines the amino acid sequence of the protein. Microfluidic system are also being developed to deliver to activate the sensor surface, provide kinetic and reproducibility studies, and precision testing of target-probe chemistries. Through incorporation with nanoscale elements, the microfluidic system will also allow the evaluation of the effect of various forms of pre-filtering on signal specificity.

Our microfluidic systems also incorporate nanofluidic components composed of nanocapillary membranes (NCMs) coupled to microfluidic channels. These NCMs promise to be important components of microfluidic systems for biological analysis as they can be used as analyte concentrators, concentrating microreactors, and molecular gates. Concentration factors of 300-fold can be achieved with NCMs in microfluidic channels, which greatly improves the detectability for sample limited biological components at trace levels. However, the fundamentals of the NCM analyte concentration process are not well understood, and therefore fundamentals of mass transport through the NCMs are being studied to gain a better understanding of the concentration process to provide more robust systems. Our initial continuum approach for modeling, involves both closed-form and numerical models of the Navier-Stokes (fluid) equations, the continuity equation, mass conservation equations for each species, and the Maxwell equations of electromagnetism. REU participants will learn to fabricate, use, and image fluids in the microfluidic devices with fluorescence microscopy. One participant may be involved with the theoretical effort, which includes computational simulations of the flow through nanofluidic channels.