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Piezoelectric single crystal actuator is useful in the micro- and nano-scaled. But the range of the operation is limited. The paper presented the amplifying mechanism of the single crystal actuator in order to amplify the output of the piezoelectric actuator in micro- and nano-applications. Due to the single crystal’s expansion when the applied signals decrease, the paper developed the adjustable spring that added to the amplifying mechanism. This paper tested the characteristics of the amplifying mechanism by designed a set of experiment device. The input and output displacement of the amplifying mechanism driven by kinds of signals were measured. It can concluded that the amplifying mechanism achieve the positive and negative displacement response and show its accuracy and stable. These excellent properties of the amplifying mechanism amplify the micro-displacement and expand the operating range of single crystal actuator in micro- and nano-positioning applications.

Accurate and rapid measuring methods for displacement of nano-scale is necessary for manipulation. Self-sensing and time-digit-conversion(TDC) are two applicable measuring methods especially suitable for room-limited workspaces and vacuum-compliance required applications, thanks to their space-saving advantage and slight thermal impact on system. The self-sensing method gives measurements in high resolution at high sampling rate but its accuracy suffers from nonlinearity, while TDC has better linearity which causes less deviation to results but has a much lower sampling rate. A Kalman filter based fusion approach with dual estimation modes and self-adaptive parameters is designed to fuse the two measurements with different sampling rates at a higher frequency. Modifications to error covariance parameters are applied to traditional Kalman filter so that sensors’ generalized errors rather than their Gaussian noises are taken into consideration, and corresponding derivation is given. A series of experiments are conducted to evaluate the performance of the fused measurement.

In the field of nanomanipulation, measurement method for the nano-scale displacement is one of the key technologies, and there are many restrictions on the sensors mounted in microscopic device. In order to reduce the influence of sensors on workspace, we fused the measurements of self-sensing and time-digit-conversion (TDC) method to estimate the measured nanometer displacement. Both of the two methods have a simple measurement circuit and are easy to be integrated. They can reduce the effect of thermal radiation on workspace and work in a vacuum environment (such as SEM chamber). We proposed a method based on Kalman filter with improved state block and neural network to obtain the fusion estimation. Our method achieved a sampling rate equal to that of self-sensing, as well as a precision higher than those of the two source methods. The linearity (R2) of our method is 0.9999915 throughout 8 μ $m$ range. Finally, we compared our method with the traditional fusion method based on statistics.

This paper proposes the method of nanoscale micro-displacement modeling and control of the piezoelectric ceramic actuator (PCA) mounted on the end of a micro-nano robot. The robot works in the vacuum chamber of a Scanning Electron Microscope (SEM). We use the time-to-digital conversion (TDC) method to measure the displacement of the PCA. For the purpose of establishing the relationship of the applied voltage and the displacement of the PCA, we designed an online modeling and control system based on PC/104. Models with different order combinations are applied to fit the transfer function of the system and the least squares method is applied to identify the parameters of each model. In addition, the second-order transfer function model is used to approximate the open-loop transfer function model of piezoelectric ceramic by comparing the model fitting rate. Specially, some open-loop control experiments are performed to verify the accuracy of the model. Furthermore, a PID controller is proposed to achieve accurate position control for the PCA. In the end, simulation results demonstrate the feasibility and effectiveness of the closed-loop control system.

Manipulation in nano-scale is important to the development of Nano-technology, while position sensing is the base of nano-manipulation. Self-sensing is a method providing true sensor-actuator collocation and especially suitable for room-limited workspace. This paper introduced a self-sensing method for displacement measurement, based on charge amplifier. The principle of self-sensing was derived from piezoelectric constitutive equations, and a charge amplifier circuit was developed to obtain the displacement of piezoelectric stack. A series of experiments were conducted to evaluate the characteristics of our method. The results of the experiments and some characteristics of charge-amplifier based self-sensing method were presented.

The micro-operation technology is developing rapidly since the miniaturization of the research object and the precision of the operation. As the actuator of micro-operation, the piezoelectric material with the inverse piezoelectric effect has been widely used in this field. A new type of actuator based on piezoelectric single crystals is characterized in this paper, and a set of test system is designed to obtain the displacement of the actuator under different voltage waveforms. The relationship between the induced voltage and output displacement is analyzed. It is found that the dynamic voltage and the output displacement show a good linear relationship, and the hysteresis of the motion is smaller than the traditional piezoelectric ceramics. This good performance of the piezoelectric single crystal actuator is expected to directly use open-loop control, greatly improve the actuator control frequency and accuracy, which can reduce the complexity of the application system.