Assistant Professor
Sibley School of Mechanical and Aerospace Engineering

Brian Kirby’s research focuses on micro- and nanofluidics, creating and evaluating scientific devices with distribution systems that use channels ranging from 10 nanometers to 40 microns in diameter. The primary objective is to study how fluids, typically water, move through such systems using electronic fields in a process called electro-osmosis.

Applications for this work include micro-scale bioanalytical devices used to separate chemical components in a fluid and the creation of high-pressure chromatography devices used for the same purpose. Microfluidics typically involves a flow through channels in microfabricated silicon, glass, or polymer systems.

The physics of microfluidic systems are well defined by continuum theory, but the changes in length scale make surface tension and electrokinetic effects important and inertial forces unimportant. Because microfabricated devices can be made with a variety of complex geometries, a number of new fluidic phenomena can be explored.

Innovative lab-on-a-chip devices are designed to miniaturize analytical or bioanalytical techniques and integrate them into a microfabricated format, Kirby explains. Techniques such as chemical separations (electrophoresis, chromatography, etc) or immunoassays are incorporated into microfabricated systems (typically glass, silicon or polymers) with a goal of increasing performance, minimizing reagent requirements, and decreasing cost.

Because micro- and nanofluidic systems are often affected by surface chemistry, Kirby’s research involves detailed surface measurements using macroscopic electrokinetic effects, contact angle measurements, ellipsometry, profilometry, atomic force microscopy, and electron microscopy.

Before arriving at Cornell, Kirby helped develop a handheld device that detects the presence of biotoxins in the atmosphere as the member of a counter-bioterrorism group at Sandia National Laboratories. “Working on this project I discovered how to package many chemical procedures on a single microchip,” he says.

Kirby was drawn to the university by the opportunity to teach and by access to the nanofabrication facility. “There is always a lot of new physics to explore in microfluidics, especially experimenting with chip designs. It is satisfying to figure out how fluids, particles and molecules move.”

Kirby, who earned his Ph.D. at Stanford, joined the Cornell faculty in August 2004, where he directs the Micro/Nanofluidics Laboratory.

Professor Kirby's Web site