Backward motion commonly exists in the stick-slip linear piezoelectric actuator, resulting in deterioration of the output performance and limiting their applications. To solve the problem, a stick-slip linear piezoelectric actuator with suppressed backward motion, achieved using an active-locking mechanism (ALM) with two mechanisms, is proposed in this paper. One mechanism involves stick-slip driving, while the other actively suppresses backward motion by clamping the slider during the backward driving process through efficient control. A prototype actuator was designed and manufactured to verify the feasibility of this method, and an experimental system was established to obtain the detailed parameters. Also, to verify the feasibility and effectiveness of the suppression effect on backward motion of the proposed actuator, the output performance of the traditional stick-slip actuator and the actuator with the ALM were compared. Based on the results, we demonstrate that the maximum output speed and maximum output force of the prototype are 2.26 mm s−1 and 1.6 N under a voltage of 100 V, respectively.

A new single vibrator piezoelectric micropump which integrated the check valve and the piezoelectric oscillator is designed in this research. The micropump mainly consists of a circular piezoelectric vibrator, a polyethylene terephthalate check valve, two rubber sealing rings, upper pump cover, and lower pump cover. In this research, in order to study output performance of the single vibrator piezoelectric pump, theoretical analysis and experimental verification of the piezoelectric pump check valve have been carried out by exploiting the method of check valves and vibrator mass separation. Experimental results show that the opening of the check valve is mainly caused by the pressure difference and the inertia force. The dominant factor of check valve opening is different under different drive frequencies. A maximum opening displacement of 19.625 μm of the check valve is obtained when the micropump is driven by a sinusoidal voltage of 60 V at 300 Hz. In addition, the maximum flow rate of 2034.7 mL min−1 is obtained when the micropump is driven by a sinusoidal voltage of 60 V at 320 Hz, and a maximum output pressure of 0.82 kPa is obtained when the micropump is driven by a sinusoidal voltage of 60 V at 140 Hz.

Sampling fluids from the small-diameter deep pipeline is a challenging problem. In this paper, a very simple, piezoelectric-actuated inertial pump (PIP) is developed using a bionic valve to solve these problems. The PIP consists of simple components, including a cantilever beam piezoelectric actuator, a hard tube, and a bionic valve made of silicone. The fluid is driven by the inertial force generated in the vibration process of the tube. A new bionic valve inspired by a heart valve has been designed which has the advantages of small flow resistance and large flow area. The authors described the working principle of PIP in detail, established the flow characteristics model of the bionic valve, and used COMSOL Multiphysics to analyze the characteristics of the bionic valve. By comparing the response characteristics of the bionic valve with different tilt angles, the optimal Angle was obtained. Finally, the experimental and simulation results were compared, and the basic performance of PIP was tested. The experimental results showed that: When the tilting angle was 45° and the valve hole diameter was 6 mm, when the voltage was 98 V and the frequency was 24.5 Hz, the maximum output flow of the piezoelectric pump was 170.25 ml/min.

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