摘要
This study introduces piezoelectric microspeaker featuring ring-actuator integrated with dual-curve spring-diaphragm design. The high-stiffness ring-actuator, combined with parallel dual-curve springs, enables large, linear displacements while preserving structural stiffness. Key features of proposed design: (1) low-stiffness parallel dual-curve springs: enhance out-of-plane displacement while maintaining structural stiffness, (2) high-stiffness ring-actuator: provides significant actuation force and displacement with consistent stress distribution across spring-diaphragm structure. Measurement in pressure-field ear simulator under 9 V-DC bias with varying AC driving signals show that, at 0.7 V-rms, proposed design improves Sound Pressure Level (SPL) by nearly 1 dB below 5.6 kHz compared to reference design, with Total Harmonic Distortion (THD) remaining below 3% from 1 kHz to 20 kHz. Furthermore, at 2.8 V-rms, proposed design achieves SPL of 80 dB (1 kHz similar to 20 kHz) while maintaining THD below 7 %.