Design, analysis and control of a fast nanopositioning stage

We present a fast flexure-based, piezoelectric stack-actuated XY nanopositioning stage which is suitable for high-speed, accurate nanoscale positioning applications. The performance of the design are analyzed using finite-element-analysis software. Experiments demonstrate that the design has a high first resonant mode at 2.7 kHz, a low cross-coupling of -35 dB and a relatively large traveling range of 25x25 mum. These results are in close agreement with the predicted FEA results. Non-linearities due to hysteresis of the piezoelectric stack actuators are present in the stage. The hysteresis effect is minimized using charge actuation. The Integral Resonant Control (IRC) method is applied to damp the first resonant mode. By implementing feedforward inversion technique, high-speed and accurate scanning performances, up to 400 Hz, are achieved.