Abstract:
To explore the versatility of speakers, a piezoelectric micro-electro-mechanical system (MEMS) speaker combining the function of a silent alarm is proposed, which mainly comprises a lead zirconate titanate (PZT) actuation layer and a rigid-flexible coupling supporting layer. Measurements performed on encapsulated prototypes mounted to an artificial ear simulator have revealed that, compared to a speaker with a rigid supporting layer, the sound pressure level (SPL) of the proposed piezoelectric MEMS speaker with a rigid-flexible coupling supporting layer is significantly higher and is especially higher by 4.1-20.1 dB in the frequency range from 20 Hz to 4.2 kHz, indicating that the rigid-flexible coupling supporting layer can improve the SPL significantly in low frequency. Moreover, the spectral distribution characteristic of its playback audio is similar to that of the commercial electromagnetic type. The device can also function as a silent alarm based on oral airflows in dangerous situations, as it performs well at recognizing words according to their unique voltage-signal characteristics, and can avoid the effects of external sound noise, body movement, long distance, and occlusion. This strategy provides inspiration for functional diversification of piezoelectric MEMS speakers.
摘要:
为了探索扬声器的多功能性,提出了一种结合静音报警功能的压电微机电系统(MEMS)扬声器,其主要包括锆钛酸铅(PZT)致动层和刚柔耦合支撑层。对安装在人工耳模拟器上的封装原型进行的测量表明,与具有刚性支撑层的扬声器相比,所提出的具有刚柔耦合支撑层的压电MEMS扬声器的声压级(SPL)明显更高,尤其是在20Hz至4.2kHz的频率范围内提高了4.1-20.1dB,表明刚柔耦合支撑层可以在低频下显著提高SPL。此外,其播放音频的频谱分布特性与商用电磁型相似。该设备还可以在危险情况下根据口腔气流作为无声警报,因为它在根据单词的独特电压信号特征识别单词方面表现良好,并且可以避免外部声音噪声的影响,身体运动,长距离,和闭塞。该策略为压电MEMS扬声器的功能多样化提供了启示。