Charge drives for scanning probe microscope positioning stages

Due to hysteresis exhibited by piezoelectric actuators, positioning stages in scanning probe microscopes require sensor-based closed-loop control. Although closed-loop control is effective at eliminating non-linearity at low scan speeds, the bandwidth compared to open loop is severely reduced. In addition, sensor noise significantly degrades achievable resolution in closed loop. s work, charge drives are evaluated as a simple positioning alternative when feedback control cannot be applied or provides inadequate performance. These situations arise in high-speed imaging, where position sensor noise can be large or where no feedback sensors are present. drives can reduce the error caused by hysteresis to less than 1% of the scan range. We review the design of charge drives and compare them to voltage amplifiers for driving lateral SPM scanners. The first experimental images using charge drive are presented.