Wang Zhaoxun, Wei Wei, Zhang Menglun, Duan Xuexin, Li Quanning, Chen Xuejiao, Yang Qingrui, Pang Wei
The State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China.
Micromachines (Basel). 2024 May 29;15(6):716. doi: 10.3390/mi15060716.
By leveraging the benefits of a high energy density, miniaturization and integration, acoustic-wave-driven micromotors have recently emerged as powerful tools for microfluidic actuation. In this study, a Lamb-wave-driven micromotor is proposed for the first time. This motor consists of a ring-shaped Lamb wave actuator array with a rotor and a fluid coupling layer in between. On a driving mechanism level, high-frequency Lamb waves of 380 MHz generate strong acoustic streaming effects over an extremely short distance; on a mechanical design level, each Lamb wave actuator incorporates a reflector on one side of the actuator, while an acoustic opening is incorporated on the other side to limit wave energy leakage; and on electrical design level, the electrodes placed on the two sides of the film enhance the capacitance in the vertical direction, which facilitates impedance matching within a smaller area. As a result, the Lamb-wave-driven solution features a much lower driving voltage and a smaller size compared with conventional surface acoustic-wave-driven solutions. For an improved motor performance, actuator array configurations, rotor sizes, and liquid coupling layer thicknesses are examined via simulations and experiments. The results show the micromotor with a rotor with a diameter of 5 mm can achieve a maximum angular velocity of 250 rpm with an input voltage of 6 V. The proposed micromotor is a new prototype for acoustic-wave-driven actuators and demonstrates potential for lab-on-a-chip applications.
通过利用高能量密度、小型化和集成化的优势，声波驱动微电机最近已成为微流体驱动的强大工具。在本研究中，首次提出了一种兰姆波驱动的微电机。该电机由一个带有转子的环形兰姆波致动器阵列和中间的流体耦合层组成。在驱动机制层面，380MHz的高频兰姆波在极短距离内产生强烈的声流效应；在机械设计层面，每个兰姆波致动器在致动器的一侧包含一个反射器，而在另一侧包含一个声学开口以限制波能泄漏；在电气设计层面，放置在薄膜两侧的电极增强了垂直方向的电容，这有利于在较小面积内进行阻抗匹配。因此，与传统的表面声波驱动解决方案相比，兰姆波驱动解决方案具有更低的驱动电压和更小的尺寸。为了提高电机性能，通过模拟和实验研究了致动器阵列配置、转子尺寸和液体耦合层厚度。结果表明，直径为5mm的转子的微电机在输入电压为6V时可实现最大角速度为250rpm。所提出的微电机是声波驱动致动器的一种新型原型，并展示了在芯片实验室应用中的潜力。
