Gail W. DePuy, Ph.D., P.E. is a Professor of Industrial Engineering at the University of Louisville in Louisville, Kentucky. Her research focus lies in the areas of production planning, healthcare engineering, and operations research. She received her Ph.D. in Industrial and Systems Engineering from The Georgia Institute of Technology, her M.S.I.E. with a concentration in Human Factors from Virginia Polytechnic Institute and State University, and her B.S. in Industrial Engineering from North Carolina State University. Dr. DePuy has authored over 80 technical papers and has served as Principal Investigator or Co-Principal Investigator on over 1.3 million dollars of funded research. Dr. DePuy is a professional engineer and a member of the Institute of Industrial Engineers, Institute of Operations Research and Management Science, and American Society for Engineering Education.
- Ph.D. in Industrial & Systems Engineering, Georgia Institute of Technology, 1995
- M.S. in Industrial & Systems Engineering, Georgia Institute of Technology, 1992
- M.S. in Industrial Engineering/Operations Research, Virginia Polytechnic Institute and State University, 1990
- B.S. in Industrial Engineering, North Carolina State University, 1988
A new technique is presented for creating an electret from a plasma-enhanced chemical vapor deposition (PECVD) multilayer film of SiO2/Si3N4/SiO2. The technique uses a direct contact silicon electrode during poling. This thin-film electret formation process capitalized on deep traps in the silicon nitride, which is known to develop from hydrogen interactions with silicon dangling bonds and, in some stoichiometries, nitrogen dangling bonds. The materials used are compatible with standard microfabrication processes, and the electret activation process is accomplished with a commercial anodic bonding system, traditionally used for bonding borosilicate glass to silicon wafers. Negative electrets with an effective surface voltage (ESV) up to -236 V and positive electrets with an ESV up to 195 V are produced. The lifetime of the electrets are evaluated by performing accelerated aging at elevated temperatures. Results indicate that the electrets are expected to provide a mean lifetime effective charge for decades at a temperature of 125 degrees C. A thin-film multilayer electret fabrication process is shown to yield electrets with a half-life 5 times greater than those values reported for other PECVD fabricated multilayer electrets. [2016-0065]