The piezoelectric stack actuator used in Scanning Probe Microscopes (SPMs) always exhibits significant hysteresis
and creep. The hysteresis and creep will reduce the positioning precision and produce the distortion in scanning images.
Therefore it is necessary to develop a model with sufficient accuracy and stability to characterize the nonlinearities of the
piezoelectric stack actuator. In this paper, a novel hysteresis and creep model and a method for on-line identifying
parameters of this model are proposed. Experiment result shows that, actuated by triangular-wave voltage, the predicting
error using the proposed model is less than 2%, which is reduced by an order of magnitude comparing with the error
directly predicted using input voltage. The validity of this method is demonstrated by experiment result.
SPM (Scanning Probe Microscope) provides "three-dimensional images" with nanometer level resolution, and some of them can be used as metrology tools. However, SPM's images are commonly distorted by non-ideal properties of SPM's piezoelectric scanner, which reduces metrological accuracy and data repeatability. In order to eliminate this limit, an "open-loop sampling" method is presented. In this method, the positional values of sampling points in all three directions on the surface of the sample are measured by the position sensor and recorded in SPM's image file, which is used to replace the image file from a conventional SPM. Because the positions in X and Y directions are measured at the same time of sampling height information in Z direction, the image distortion caused by scanner locating error can be reduced by proper image processing algorithm.