The Pennsylvania State University
The extraordinary stability of quartz resonators and accuracy of around 30 ms per year has made them the most ubiquitous time sensors. Micromachining quartz offers various new configurations and advantages for gravimetric, thermal, viscoelastic, and magnetic sensing. Specifically, this talk will demonstrate the applications of micromachined bulk acoustic wave resonators for the systematic investigation of adsorbing films and nanomaterials on their surface. The response of the resonators to various surface loads has been carefully modeled assuming a dynamically forming viscoelastic film under a fluidic overlayer. Micromachined shear wave resonators, have been investigated for their response to organized ferrofluids atop the resonator electrodes. This configuration was capable of achieving magnetic field sensitivities in the nanoTesla range in addition to providing insight into the process of ordered assembly of ferrofluid particles at the interface. Finally the talk will demonstrate thermal sensing capabilities of micromachined quartz resonators. As we will see, no matter the configuration of the sensing application, quartz MEMS are only a matter of time!
Srinivas Tadigadapa, is a Professor of Electrical Engineering and Bioengineering at the Pennsylvania State University. He obtained his Ph.D. from Cambridge University, UK in 1994. 1996-2000 he was Vice President of Manufacturing at Integrated Sensing Systems Inc., Michigan and was involved with the design, fabrication, packaging, reliability, and manufacturing of micromachined Coriolis mass flow sensors and pressure sensors. His current research interests include integrated heterogeneous materials based microsystems, bio and chemical sensors, and exploring electric and thermal transport at the micro-nano interfaces. He has been a research fellow at the University of Karlsruhe, Germany and a Visiting Professor at Otto von Guericke University, Magdeburg, Germany, and University College, Cork, Ireland. He has been the recipient of the Alexander von Humboldt fellowship in Germany and the Walton Fellowship by the Science Foundation of Ireland. He is a life fellow of the Cambridge Philosophical Society, Fellow of the Institute of Physics, London, Senior Member of IEEE, and currently serves as an associate editor of the Journals: Measurement Science and Technology and SPIE Journal of Microlithography, MEMS, and MOEMS.