Abstract:
At Cornell, we have found that high stress Silicon Nitride resonators exhibit extraordinarily low loss (high Q). We are investigating the dependence of the Q on mode shape in these devices. In contrast, graphene resonators, exhibit much higher loss for reasons that are as yet unclear. I will discuss the progress in understanding of the energy loss mechanisms in both of these systems. Compressively stressed doubly clamped resonators operated near the buckling transition present a very different opportunity. Here the devices exhibit rapid changes in resonant frequency due to changes in stress, and I will discuss their potential use as sensors for trace gasses from ambient air.
Coffee and tea will be served 20 minutes prior to the seminar.