Integrated high-frequency piezoelectric transducer within radial critical dimension of piezoceramics

Although high-frequency ultrasonic micromachining systems have shown great advantages in microstructure manufacture with high efficiency and accuracy, the potential applications have been limited by the poor performance of insufficient power, transverse vibration interference, and modal dense interference of high-frequency piezoelectric transducers. To address these limitations, an integrated high-frequency piezoelectric transducer (IHPT) was proposed to obtain the pure longitudinal vibration mode by electromechanical equivalent circuit model. Furthermore, finite element method was performed to explore the radial critical dimension effect for the optimal diameter of piezoceramics stack and to suppress transverse vibration interference and modal dense interference by structure optimization of tool rod shape. Finally, prototype tests were conducted to verify the design theory and simulation optimization. The experimental results showed that the designed IHPT has the characteristics of high power, large vibration amplitude, and wide resonance frequency band. Besides, the transverse vibration amplitude is limited to less than 0.1μm and modal dense interference is eliminated within the resonance frequency band of ± 6 kHz. Above results demonstrate that the proposed IHPT within radial critical dimension not only overcomes existing shortcomings of high-frequency piezoelectric transducers, but also provides an integrated design method and simulation reference to improve insufficient power, transverse vibration interference and modal dense interference, which is highly desired in ultra-precision ultrasonic micromachining systems.