Hu Wang

To address the difficulty in accurately describing the motion behavior of linear piezoelectric inertial stick–slip actuators in micro-/nano-precision positioning due to nonlinear friction and the coupling of structural parameters, this paper presents a systematic study on their motion mechanism, friction characteristics, and dynamic behavior. The step-accumulation and scanning operation modes of the actuator are analyzed to clarify the fundamental motion principles. A nonlinear LuGre model is introduced, based on which a comprehensive dynamic model incorporating the piezoelectric actuator, inertial mass, and friction interface is established. Numerical simulations in MATLAB/Simulink are conducted to investigate the effects of key structural and driving parameters on the output performance. The results indicate that shortening the step response time of the piezoelectric actuator, appropriately increasing the inertial mass, and raising the driving voltage can effectively enhance the driving speed, whereas excessive friction significantly reduces motion efficiency. The findings provide a theoretical reference for the design and performance optimization of linear piezoelectric inertial stick–slip actuators.

The large load loss of piezoelectricity pumps leads to fluid energy in the fluid chamber during fluid transportation. In this paper, the output performance of a piezoelectricity pump is improved by changing the structure parameters of the fluid chamber to reduce the fluid load. The mechanism of fluid flow energy loss in the body cavity of hydraulic pumps is simulated and analyzed, and the influence of the dimensions of the inlet and outlet valves and the height of the cavity on fluid energy loss is obtained. The flow rate and pressure of inlet and outlet valves with different cavity heights and different driving frequencies are obtained. The results show that the flow rate and output pressure of the hydraulic pump are optimized when the cavity height is 3 mm, and the inlet and outlet valve diameters are 2.5 mm.

In order to investigate the optimal power generation performance of piezoelectric materials, a spin-magnetic piezoelectric generator was designed and the relationship between output voltage and speed and external force was derived through theoretical analysis. The maximum deformation and resonant frequency of the piezoelectric oscillator under magnetic drive are derived from simulation analysis. Finally, the relationship between output voltage and magnet size, distance between two magnets, and speed was tested experimentally, and the experimental data agreed with the theoretical analysis. The results show that when the speed is 312 r/min, magnet pitch is 12 mm, and magnet size is 10 mm 35 mm 4, the maximum output voltage is 54 V. This can meet the power supply needs of micro and small electronic products.

This paper describes the design of a piezoelectric-driven hydraulically amplified Braille-flexible bump device that enables the flexible formation of Braille characters. A piezoelectric vibrator is used to excite fluid resonance in a cavity, and displacement is realized by compressing the fluid, allowing Braille character dots to be formed. First, the structural design and working principle of the device, as well as the method used to drive the fluid, are explained. Expressions for the output displacement and amplification ratio of the flexible film and piezoelectric vibrator are then obtained through kinetic analysis of the system unit. Subsequently, the structural parameters that affect the output displacement and the liquid amplification are described. Finally, experimental tests of the system are explained. The results indicate that the output displacement of the contact formed by the flexible film reaches 0.214 mm, satisfying the requirements of the touch sensitivity standard for the blind, when the fluid cavity diameter measures 31 mm and the resonance frequency is 375.4 Hz. The corresponding water discharge is 8.8 mL. This study proves that constructing a Braille bump device in this way is both feasible and effective.