Microelectromechanical Systems (MEMS) Based-Ultrasonic Electrostatic Actuators on a Flexible Substrate

Kim, Sangpyeong; Zhang, Xu; Daugherty, Robin; Lee, Ed; Kunnen, George R.; Allee, David R.; Forsythe, Eric; Chae, Junseok

doi:10.1109/led.2012.2195630

Cited by 16 publications

(5 citation statements)

References 13 publications

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“…In the first three symmetric mode shapes, (0,1)-(0,3), the absolute maximum displacement amplitude at 176 Hz corresponds to the mode shape (0,1) of the circular diaphragm, which can be modeled as displacement amplitude z 01 ðrÞ using Eq. (11). Then, using the Rayleigh integral of Eq.…”

Section: Resultsmentioning

confidence: 99%

Vibration and sound radiation of an electrostatic speaker based on circular diaphragm

Chiang

Huang

2015

The Journal of the Acoustical Society of America

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This study investigated the lumped parameter method (LPM) and distributed parameter method (DPM) in the measurement of vibration and prediction of sound pressure levels (SPLs) produced by an electrostatic speaker with circular diaphragm. An electrostatic speaker with push-pull configuration was achieved by suspending the circular diaphragm (60 mm diameter) between two transparent conductive plates. The transparent plates included a two-dimensional array of holes to enable the visualization of vibrations and avoid acoustic distortion. LPM was used to measure the displacement amplitude at the center of the diaphragm using a scanning vibrometer with the aim of predicting symmetric modes using Helmholtz equations and SPLs using Rayleigh integral equations. DPM was used to measure the amplitude of displacement across the entire surface of the speaker and predict SPL curves. LPM results show that the prediction of SPL associated with the first three symmetric resonant modes is in good agreement with the results of DPM and acoustic measurement. Below the breakup frequency of 375 Hz, the SPL predicted by LPM and DPM are identical with the results of acoustic measurement. This study provides a rapid, accurate method with which to measure the SPL associated with the first three symmetric modes using semi-analytic LPM.

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Section: Resultsmentioning

confidence: 99%

Vibration and sound radiation of an electrostatic speaker based on circular diaphragm

Chiang

Huang

2015

The Journal of the Acoustical Society of America

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“…The traditional electromagnetic, capacitive speakers still cannot be replaced by the MEMS ones for their relatively large permanent magnet [11,12], or limited by the pull-in effect and high driving voltage [13,14]. Piezoelectric MEMS speakers based on the reverse piezoelectric effect are gradually attracting attention for the advantages of low power consumption, high theoretical sound pressure level (SPL), and mass production [15][16][17][18]. However, piezoelectric MEMS speakers still suffer from the challenge of low SPL, although researchers have adopted new working principles, structures and driving electrodes [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Unsealed piezoelectric MEMS speaker with rigid-flexible composite membrane

Wang,

Hu,

Ruan

et al. 2024

J. Micromech. Microeng.

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In this paper, we propose an unsealed piezoelectric microelectromechanical systems (MEMS) speaker with rigid-flexible composite membrane, which can eliminate the membrane separation and the vibration displacement limitation at high driving voltage compared to that with the sealed rigid-flexible coupling membrane demonstrated in our previous work. Measurements performed on encapsulated prototypes mounted to an artificial ear simulator have revealed that in the human audible range of 20 Hz-20 kHz, higher than 68.5 dB SPL are obtained at 2 V, and greater than 89.6 dB SPLs are achieved at 10 V. Moreover, the SPL distribution and effective SPLs at each moment when playing the same song exhibit similar characteristics to those of a commercial electromagnetic one. This piezoelectric MEMS speaker achieves high SPLs meeting the basic hearing needs of the human, and will have excellent prospects for future wearable audio electronics.

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“…Piezoelectric MEMS speakers based on the reverse piezoelectric effect are gradually attracting attention for the advantages of low power consumption, high theoretical sound pressure level (SPL), fast response, as well as being dust-free, and viable for mass production. Therefore, piezoelectric materials provide a potential solution for MEMS speakers [ 17 , 18 , 19 ]. Researchers have developed various piezoelectric materials, such as ZnO [ 20 , 21 ], AlN [ 22 ], PZT [ 23 , 24 ], PMN-PT [ 25 , 26 , 27 ], and PZN-PT [ 28 ].…”

Section: Introductionmentioning

confidence: 99%

A Piezoelectric MEMS Speaker with a Combined Function of a Silent Alarm

Wang

Ruan

et al. 2023

Micromachines

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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.

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Microelectromechanical Systems (MEMS) Based-Ultrasonic Electrostatic Actuators on a Flexible Substrate

Cited by 16 publications

References 13 publications

Vibration and sound radiation of an electrostatic speaker based on circular diaphragm

Vibration and sound radiation of an electrostatic speaker based on circular diaphragm

Unsealed piezoelectric MEMS speaker with rigid-flexible composite membrane

A Piezoelectric MEMS Speaker with a Combined Function of a Silent Alarm

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