Topic: Development of High Efficiency Smart Materials for Energy Harvesting, Space and Environmental Applications
Speaker: Dr. Padmaja “Paddy” Guggilla, Assistant Professor of Physics, AAMU
Date & Time: Tuesday, October 1, 2013, 1:00 PM
Place: Room 140 VMC (Chambers Hall)
Environmental energy harvesting to power low energy consuming system has become a very flashy topic because of the large development of wireless sensor networks. Several energy harvesters have been proposing a wide variety of ways to meet present requirements. Pyroelectricity, electrical current generation from time dependent temperature fluctuations is one of the technologies very widely used in commercial applications even with a very low efficiency rate. Current research is based on developing high efficiency smart systems that harvest the environmental energy and produce electrical energy that can be stored in capacitors or batteries and used when harvesting is not possible. Best known pyroelectric materials such as Lead zirconate titanate (PZT), Lead Zirconate (PbZrO3), Lead Titanate (PbTiO3), Lithium Tantalate (LiTaO3), Polyvinylidenedifluoride (PVDF), Polyvinyledenedifluoride–trifluoroethylene (PVDF –TrFE) are fabricated by doping them with a variety of dopants that enhance the pyroelectric properties of these materials. The dopants included Lanthanum (La), Praseodymium (Pr), Manganese (Mn), Silver nano particles (Ag), and Multi walled carbon nanotubes (MWCNT) etc. A variety of smart material fabrication techniques is used at AAMU, which include solution casting, screen printing, spray coating and spin coating. All the samples were characterized for their optical, mechanical, chemical and electrical properties using XRD, SEM, AFM, FTIR, RAMAN, in bulk, thick and thin film forms with various compositions and wt% of ceramic powder particles to find the best smart material for energy harvesting purposes. All the samples were investigated as pure, with dopants, and by adding multiple layers of these materials to achieve larger current and figures of merit. Other influential technical parameters such as the applied poling field and the thickness of the samples are also analyzed. Two novel smart material systems fabricated at AAMU, lanthanum modified lead zirconate titanate and MnO2 doped lead lanthanum zirconate titanate, show high pyroelectric efficiency than the existing materials which is very promising for energy harvesting, space and environmental applications. A few applications of current research include pollution detection in air, gas leak sensing, flame detection, water quality, breathe detection of alcohol and for other environmental testing.
Dr. Padmaja “Paddy” Guggilla is working as an Assistant Professor of Physics in the Department of Physics, Chemistry and Mathematics, AAMU since Fall 2008. Previously, Dr. Guggilla was an adjunct professor at Drake State Technical College, Huntsville, AL. Dr. Guggilla received her Ph. D. in Applied Physics in 2007, MS in Electrical Engineering from UAH in 2003. Dr. Guggilla has been extremely successful in writing grants with over a million dollars in funding as PI, another million dollars+ as Co-I. Dr. Guggilla has been invited to give technical talks, review proposals from NSF and DOD, and papers from reputed journals. She has published over 35 papers including a book chapter and received “Most Effective New Faculty of the Year” award for 2009.
Refreshments will be served at 12:45 PM