Event
Bioengineering Seminar Series: Frances Ligler
Wednesday, October 14, 2009
11:00 a.m.
Kay Boardrooms, Jeong H. Kim Engineering Building
Professor William Bentley
bentley@umd.edu
Please note special day and location.
Hydrodynamic Focusing for Sensing and Micro/Nano-Fabrication
Presented by Frances LiglerSenior Scientist for Biosensors and Biomaterials
Center for Bio/Molecular Science and Engineering
Naval Research Laboratories
Flow in microfluidic channels is laminar, i.e. streams flow in parallel without mixing. This absence of convection has both facilitated and frustrated the development of lab-on-a-chip systems. A plethora of publications describe mixers designed to overcome laminar flow limitations at low Reynolds numbers. The development of simple mixing structures in the microchannel walls started my lab on path to design microfluidic structures for a wide variety of applications including sensors and microflow cytometers. We learned to use hydrodynamic focusing of one laminar stream by another for separations, optical components, biosensors, cell analysis, and micromanufacturing. The journey I will describe includes target focusing to the sensor surface, creating fluid walls to confine electrical fields, fabricating flow cytometers for detecting pathogens in nasal wash or identifying marine algae, and manufacturing polymers with defined cross-sectional shapes. New contributions to general utilization of hydrodynamic focusing include an example of inertia at Reynolds numbers between 1 and 10 (where it is not supposed to exist) and reversal of hydrodynamic focusing to recycle sheath fluid in the flow cytometer (reversal has been demonstrated in simple mixers but not for analytical devices).
Frances S. Ligler is the Navys Senior Scientist for Biosensors and Biomaterials and Chair of the Bioengineering Section of the National Academy of Engineering. She earned a B.S. from Furman University and both a D.Phil. and a D.Sc. from Oxford University. Currently working in the fields of biosensors and microfluidics, she has also performed research in biochemistry, immunology, and proteomics. She has over 300 full-length publications and 33 patents, which have been cited over 6100 times. She is the winner of the Navy Superior Civilian Service Medal, the National Drug Control Policy Technology Transfer Award, the Chemical Society Hillebrand Award, Navy Merit Award, NRL Technology Transfer Award, three NRL Edison Awards for Patent of the Year, the Furman University Bell Tower and Distinguished Alumni of the 20th Century Awards, and the national Women in Science and Engineering (WISE) Outstanding Achievement in Science Award. She was elected the chair of the 1994 Gordon Research Conference on Bio/Analytical Sensors and an SPIE Fellow, and serves as an Associate Editor of Analytical Chemistry and a regional editor for the Americas for Biosensors & Bioelectronics. In 2003, she was awarded the Homeland Security Award (Biological, Radiological, Nuclear Field) by the Christopher Columbus Foundation and the Presidential Rank of Distinguished Senior Professional by President Bush.
