Virginia Tech Mechanical Engineering Annual Report 2019 Annual Report | Page 12

Liquid droplets paving the way for highly sensitive sensors Jiangtao Cheng Associate Professor Research Focus: Optofluidic so- lar concentra- tors based on electrowetting on dielectric- driven liquid prisms Sensitive, miniaturized sens- ing systems are important for medical and environmen- tal diagnostic and monitor- ing applications. Chip scale integrated photonic sens- ing systems that combine optical, electrical, and fluidic functions are espe- cially attractive for sensing applications due to the high sensitivity of optical sensors, the small form-factor of chip scale systems, and the low processing cost. While optical sensing with a detection limit down to single nanoparticles has been achieved by various methods, microcavity sensing attracts much attention because their high quality factors (Q factor) and small mode volumes enable significant enhancement of light-matter interactions. Microcavity sensing has seen tremendous progress and the sensing performance has been demonstrated by detecting single biological molecules. However, detection in liquids with whispering gallery mode (WGM, i.e., closed circular beams supported by total internal reflections at the external cavity interface) cavities was achieved only in rare cases. No real and stable high Q-factor sensing experiment with non-solid optical resonators has been reported to date. Creating intelligent tires for safer automobiles The concept of intelligent tires was introduced more than a decade ago. Various tire companies invested in developing this technology internally and a few have come to market with a preliminary product. The idea is to measure, in real-time, the tire vibration characteristics and make indication of various important parameters such as road surface type and condition, fric- tion potential, wear, hydroplaning, health monitoring, and load. Knowledge about any of the above parameters could potentially help with improving safety of the transportation system, specially with autonomous vehicles. At CenTiRe, research on this topic started 8 years ago and continues towards realization of the concept into a viable prod- uct. With funding from NSF and several tire companies, we have been able to put the intelligence in the tire. One such example is a real-time machine learning algorithm which can predict the road surface type and its state (wet, dry, snow, or ice). Cur- rent efforts are focused on estimating friction between the tire and the road and feeding that information into the advanced chassis control systems on-board the vehicle (ABS, VSC, ADAS, etc.) 12 Revised and Corrected, Nov. 2019 Saied Taheri Professor Research Focus: Tire and ve- hicle dynamic modeling and simulation; Intelligent tire development and application; Vehicle chassis systems control