Active damping of the scanner for high-speed atomic force microscopy

The scanner that moves the sample stage in three dimensions is a crucial device that limits the imaging rate of atomic force microscopy. This limitation derives mainly from the resonant vibrations of the scanner in the z direction (the most frequent scanning direction). Resonance originates in the scanner’s mechanical structure as well as in the z piezoactuator itself. We previously demonstrated that the resonance originating in the structure can be minimized by a counterbalancing method. Here we report that the latter resonance from the actuator can be eliminated by an active damping method, with the result the bandwidth of the z scanner nearly reaches the first resonant frequency (150kHz) of the z piezoactuator.