Oscillation-synchronous control of a frequency-measuring atomic force microscope

We present a frequency-measuring atomic force microscope (AFM) system which uses a novel oscillation-synchronous period-feedback controller. Execution of the AFM's control algorithm synchronously to the tip oscillation allows low-noise and high-precision surface tracking. We use a digital FPGA-based controller to implement this control technique. We use simulation and experimental results to demonstrate the effectiveness of this method.