This study presents a novel impact piezoelectric motor that excites double stators through a sinusoidal signal. A sawtooth signal drives the traditional impact piezoelectric actuator, and its working frequency is limited by the resonant frequency. This study uses sine signals to drive the double stators to produce a sinusoidal vibration. The sinusoidal vibration of different frequencies and amplitudes are synthesised into a sawtooth vibration on the stage plate. The directional movement of the slider is realised using the vibration of the stage plate to drive the slider. This structure reduces the space required for the piezoelectric actuator to work. The working principle of the motor is discussed, and the structure is constructed. The dynamics model of the whole system is established on the based of the dynamics model of the actuator and the LuGre friction model. Moreover, the dynamics model was simulated and analysed through MATLAB/Simulink. The prototype is fabricated and tested. Experimental results confirm the effectiveness of using sinusoidal signals to drive the piezoelectric actuator, and the motion process of the piezoelectric motor is consistent with the theoretical analysis. The maximum speed of the piezoelectric actuator is 5.54 mm/s, and the resolution is 0.72 μm. This study provides an effective driving method for the quasi-static piezoelectric motor to improve the working frequency.

A novel impact piezoelectric actuator is proposed in this paper to achieve cross-scale driving, which can realise high resolution and high speed. The piezoelectric actuator is mainly composed of four diamond-shaped flexible hinges, which can consider a certain stiffness and flexibility. The operating principle of the piezoelectric actuator is introduced. The actuator is excited by two sinusoidal waves with a frequency ratio of 1:2 to achieve impact drive at quasi static state. The appropriate structural parameters are obtained by simulation. The actuator is designed to make the frequency ratio of first and second vibration modes 1:2, which can achieve impact drive at resonant state. The prototype is fabricated, and the characteristics are tested. The measured resonant frequency ratio is consistent with the simulated value. Experimental results show that when the prototype works at quasi-static state, the resolution is 37 nm with driving voltages of 12 Vp-p; at resonant state, the no-load maximum speed is 125.43 mm/s and the maximum load is 0.5 N when the driving frequency and voltages are 1.95 kHz, 40 Vp-p and 3.90 kHz, 160 Vp-p, respectively. The proposed actuator can be used for precision positioning and can improve the accuracy and the efficiency of processing instruments.

An inertia piezoelectric motor based on bipedal driven, which can work in not only quasi-static but also resonant states, is proposed, designed, fabricated and studied considering the high resolution of quasi-static piezoelectric motor and the high speed of resonant piezoelectric motor. The two stators of the piezoelectric motor are drived by two sinusoidal electrical signals with 1:2 frequency ratio to generate sinusoidal vibration on the corresponding driving foot. A continuous step motion without frequency limitation is realised under the action of inertia and friction forces after synthesising the sinusoidal vibration of different frequencies into mechanical sawtooth vibration. The natural resonant frequencies of the piezoelectric motor are adjusted to a specific proportion to combine the vibrations in the resonant state through finite element analysis. In the structure of two stators, each stator has a corresponding inertia block, and the corresponding resonant frequency can be altered by adjusting the mass of the inertial block without affecting the other resonant frequency, thus markedly simplifying the design difficulty of the piezoelectric motor which can work in quasi-static and resonant states. The motion characteristics of the prototype are tested by building the prototype and experimental platform. Experimental results show that the maximum speed of the prototype is 29.3 mm/s and the maximum load is 200 g in the resonant state, the minimum displacement resolution of prototype motor is 0.26 μm in the quasi-static state. The motion characteristics of the prototype are consistent with the theoretical analysis, which provides an effective idea to improve the comprehensive performance of the piezoelectric motor.

A resonant screw-driven piezoelectric motor operating in single-mode vibrations is proposed, designed, manufactured, and studied. The motor is constructed with a stator and a threaded rotor. The stator consists of a hollow parallelogram metal elastomer and two piezoelectric ceramic plates. The motor is excited by a single-phase signal to produce two separate vibration modes: the first expansion mode (B1 mode) and the second expansion mode (B2 mode). Each mode drives the threaded rotor in one direction, and the bidirectional motion is achieved by switching the two modes. The construction is designed, and modal simulation is performed using finite element software to determine the structural parameters. A frequency-domain analysis is performed to obtain the frequency response characteristics, and the motion trajectories of the stator are obtained using transient analysis. Finally, a prototype is produced, and experiments are conducted. Experimental results indicate that the no-load speeds of the motor under the 200 Vp-p voltage excitation are 1.67 and 1.04 mm/s in the two modes, which correspond to maximum loads of 35 and 20 mN, respectively.