Q control of a microfabricated piezoelectric cantilever with on-chip feedthrough cancellation

One of the major prerequisites to obtaining highspeed tapping-mode atomic force microscopy (AFM) is a controllable quality (Q) factor. This can be achieved through the use of self-sensing cantilevers that utilize piezoelectric actuation. However, such cantilever configurations commonly feature significant levels of feedthrough from the actuation signal to the sensing signal that buries the dynamics of the cantilever, and correspondingly increases the complexity of the control implementation, especially for higher imaging modes. Here we demonstrate a novel active AFM cantilever fabricated with a separate piezoelectric actuator and sensor, together with an electrode configuration that is designed to significantly reduce feedthrough. This enables a simplified approach to controlling the cantilever's dynamics, which is demonstrated through the implementation of an effective Q control method for high-speed AFM scanning.