An Electret-Augmented Low-Voltage MEMS Electrostatic Out-of-Plane Actuator for Acoustic Transducer Applications
An Electret-Augmented Low-Voltage MEMS Electrostatic Out-of-Plane Actuator for Acoustic Transducer Applications
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DOI：
10.3390/mi11030267
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发表时间：
2020-03-01
期刊：
影响因子：
3.4
通讯作者：
Toshiyoshi, Hiroshi
中科院分区：
文献类型：
--
作者：
Sano, Chikako;Ataka, Manabu;Toshiyoshi, Hiroshi
尽管在各种应用中发展了高能效设备，但微电子机械系统(MEMS)静电执行器仍然需要高电压来产生大位移。在这方面，具有准永久电荷的驻极体允许将大的固定电压直接集成到电极结构中，以减少或消除对直流偏置电子设备的需求。由于硅微机械加工和钾离子驻极体制作方法的高度兼容性，在面向2µm间隙的绝缘体上硅(SOI)结构的内表面上制作了-40V偏置驻极体层以进行验证。在交流输入电压为Vin=5Vpp的情况下，具有离面运动膜的-10V驻极体增强型驱动器的最大声压级(SPL)达到50分贝，这表明声学换能器(如微音箱)具有潜在的应用前景。这种具有驻极体偏置的器件只需要输入信号电压，因此有助于降低器件系统的总体功耗。
Despite the development of energy-efficient devices in various applications, microelectromechanical system (MEMS) electrostatic actuators yet require high voltages to generate large displacements. In this respect, electrets exhibiting quasi-permanent electrical charges allow large fixed voltages to be integrated directly within electrode structures to reduce or eliminate the need of DC bias electronics. For verification, a -40 V biased electret layer was fabricated at the inner surface of a silicon on insulator (SOI) structure facing a 2 mu m gap owing to the high compatibility of silicon micromachining and the potassium-ion-electret fabrication method. A -10 V electret-augmented actuator with an out-of-plane motion membrane reached a sound pressure level (SPL) of 50 dB maximum with AC input voltage of Vin=5 Vpp alone, indicating a potential for acoustic transducer usage such as microspeakers. Such devices with electret biasing require only the input signal voltage, thus contributing to reducing the overall power consumption of the device system.