A novel cylindrical ultrasonic motor easy to be fixed is proposed in this article. There are threaded holes on the bottom of stator used for fixing, distinguishing it from other cylindrical stators. The bottom is machined as a round lug boss. Its radius is smaller than the inner radius of the stator in order not to affect the excitation of vibration mode. The finite element analysis was accomplished to verify the working principle. Based on the analysis, a prototype was fabricated and measured. The mechanical output characteristics were obtained by experiments. The maximal velocity of the proposed motor is 170 r/min at the operating frequency of 31.6 kHz.

A novel linear-type piezoelectric ultrasonic actuator for application in a Smart Fuze Safety System (SFSS) is investigated in this paper. Considering the requirements of SFSS, the structural parameters of the piezoelectric ultrasonic actuator are initially determined. Furthermore, sensitivity analysis of the structural parameters to the frequency consistency is conducted using finite element (FEM) software. To validate the results of FEM, the frequency sweep tests of the piezoelectric ultrasonic actuator are performed to determine the stator's actual working mode frequencies with PSV-300-B Doppler laser vibrometer system. Additionally, the results of frequency sweep test are compared with that of the FEM analysis, and further verified by impedance analyzer. To investigate the overall performance of the piezoelectric ultrasonic actuator, vibration modes of actuator's stator, output speed and force of the piezoelectric ultrasonic actuator are tested. The experimental results show that the output speed and force of the actuator can reach 88.2 mm/s and 2.3 N respectively, which can meet the demands of the SFSS.

Electrothermal actuators, with their simple structure, small size, strong anti-interference ability, and easy integration, have emerged as a promising solution for micro-drive technology. However, deploying them in extreme environments, such as the fuze systems—which demand exceptional reliability under high mechanical overloads. In this study, a device based on multi-electrothermal co-actuation is designed for the fuze system of loitering munition. The overall structure and work principle of the multi-electrothermal co-actuation device is discussed. Considering application environments, the effect factors of V-beam numbers, air gap, type of contact surface, external load force, periodic voltage and gas damping on the output performance of the multi-electrothermal co-actuation device are systematically addressed via simulation and experimental method. Furthermore, the high overload resistance performance of the co-actuation device applied in loitering munition is studied. The results show that the proposed multi-electrothermal co-actuation device could operate stably under a high overload (12,000 g/73.79 μs) environment, fully meeting the demanding requirements of fuze system for loitering munition. In addition, this study identifies laser processing-induced thermal gradients and mechanical stresses as critical fabrication challenges. This study provides significant insights into the design and optimization of multi-electrothermal actuation systems for next-generation fuze applications, establishing a valuable framework for future development in this field.

In this paper, a bidirectional micro-device based on multi-electrothermal co-actuation is proposed for a fuze safety system, combining the advantages of the simple structure, small size, low input voltage, large output, and absence of electromagnetic interference in electrothermal actuators. Based on the working principle of the multi-electrothermal co-actuation device and the mathematical model of the single V-shaped electrothermal actuator established in this paper, the temperature distribution of the V-shaped electrothermal actuator is simulated. In addition, the dynamic response and the effect of geometric factors on the output performance of the multi-electrothermal co-actuation device are analyzed in detail. Furthermore, driving characteristics tests of the electrothermal micro-device are carried out. The experimental findings indicate that a displacement of approximately 258.95 μm with a response time of about 156.51 ms can be achieved by the V-shaped electrothermal actuator when the applied voltage is 1.2 V. In a single cycle, a total displacement of 340 μm is obtained by the co-actuation device in around 1.28 s.

A novel micro-mirror driven by hybrid photoelectric-electrostatic actuation of PLZT ceramic is proposed based on the anomalous photovoltaic effect of PLZT ceramic. On the basis of analysis of coupling relationships of multi-physics fields of PLZT ceramic, the photovoltage of PLZT ceramic is established during illumination and light off phases. Furthermore, the relationship between the driving displacement and the photovoltage of PLZT ceramics is present. In addition, the feasibility of micro-mirror with hybrid photoelectric-electrostatic driving is verified via closed-loop control for photovoltage of PLZT ceramic. The experimental results show that the photovoltage of PLZT ceramics has good dynamic control precision using on-off closed-loop control method.