Virginia Tech Mechanical Engineering Annual Report Annual Report 2016 | Page 27

27 Deepam Maurya Shashank Priya NBT-based ceramics promising alternative to lead-based piezoelectric materials Working with Shashank Priya, the Robert E. Hord Jr. Professor of Mechanical Engineering and Associate Director for Scholarship and Research at the Institute for Critical Technology and Applied Science (ICTAS), post-doctoral researcher Deepam Maurya has been looking to find an alternative to lead-based piezoelectric ceramic materials since earning his doctoral degree from Virginia Tech in 2012. Lead zirconate titanate, known as PZT, is one of the world’s most often used piezoelectric ceramic materials – and is made up of more than 50 percent lead. While PZT components are normally very small, the numbers of these lead-based products is staggering; and finding a suitable replacement will yield enormous economic and environmental benefits. Lead toxicity has caused a growing demand around the world for the elimination of lead from many consumer items such as cell phones, auto focus cameras and fuel injectors. “We’ve discovered we can achieve similar properties such as high piezoelectric response and high temperature stability in a lead-free material.” The patented lead substitute, which Maurya calls ‘NBT-based ceramics’ is a significant improvement over previous compounds as the mixture. When combined with a special synthesis process that aligns the grains in the ceramic along a preferred crystallographic direction this material exhibits excellent temperature stability, giant electric field induced strain, and ultra-low hysteresis. In short, it achieves the optimum combination of most of the relevant electromechanical parameters necessary to be a viable alternative to traditional PZT. The pair had a paper published on their work in 2015 that can be found in Scientific Reports.