Imaging Multimode Vibrations in High-Frequency Aluminum Nitride Piezoelectric Nanomembrane Resonators

We report on the first imaging and visualization of the multimode resonant behaviors of aluminum nitride (AlN) piezoelectric nanomembrane resonators, by exploiting a spectromicroscopy technique based on scanning laser interferometry. High-frequency multimode vibrations (up to 33MHz) with quality (Q) factors up to ~8500 are observed in the AlN nanomembranes. Both undriven thermomechanical and coherently excited vibrations of the devices are measured and spatially mapped. Such a multimode AlN device platform with abundant resonant modes, two-dimensional (2D) large capturing surfaces, and efficient all-electrical signal transduction, holds strong promise for enabling ultrasensitive gravimetric detection, mass spectroscopy, and inertial imaging.