Sensor-less Vibration Suppression and Scan Compensation for Piezoelectric Tube Nanopositioners

Piezoelectric tube scanners are employed in highresolution positioning applications such as scanning probe microscopy and nano-fabrication. Much research has proceeded with the aim of reducing hysteresis and vibration, the foremost problems associated with piezoelectric tube scanners. In this paper, two simple techniques are proposed for simultaneously reducing hysteresis and vibration. Experimental results demonstrate significant reduction in hysteresis due to the use of a charge amplifier. Previous problems involved with the implementation of such ampliers are resolved to provide DC accurate performance with zero voltage drift. Secondly, piezoelectric shunt damping, a technique previously resident in the field of smart structures, is applied to damp tube vibration. By attaching an LCR impedance to a single tube electrode, the first mechanical mode is reduced in magnitude by more than 20 dB.