A Novel MEMS Speaker with Peripheral Electrostatic Actuation

Garud, MV and Pratap, R (2020) A Novel MEMS Speaker with Peripheral Electrostatic Actuation. In: Journal of Microelectromechanical Systems, 29 (4). pp. 592-599.

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Abstract

We design and fabricate electrostatically actuated micro-speakers with circular diaphragms and peripheral electrode configuration. The novel electrode configuration mitigates the squeeze film damping and increases pull-in voltage when compared with the conventional parallel plate electrostatic transducer design. Finite element analysis shows that under dynamic conditions, we can achieve diaphragm deflections as much as 80 times the gap between the electrodes because of the proposed design. We compare the conventional design of electrostatically actuated audio speakers - where typical electrode separation gaps are around 60 to 100μm and actuation voltages are in the range of 10 to 200 volts - with the proposed peripheral electrode design with an electrode separation gap of 1μm and actuation voltage �100 volts. The SPL obtained is comparable to the existing designs and ranges from 40 to 60 dB at 1 kHz at 1 cm with different sizes of the micro-speakers. The efficiency achieved with the proposed design is 100-4 at resonance which is at least two orders higher than the typically observed value for electrostatic micro-speakers. 2020-0134 © 1992-2012 IEEE.

Item Type:	Journal Article
Publication:	Journal of Microelectromechanical Systems
Publisher:	Institute of Electrical and Electronics Engineers Inc.
Additional Information:	The ccopyrifht of this article belongs to Institute of Electrical and Electronics Engineers Inc.
Keywords:	Damping; Electrostatic actuators; Electrostatics; Squeeze films, Circular diaphragms; Conventional design; Diaphragm deflection; Electrode configurations; Electrode separation; Electrostatic actuation; Electrostatic transducers; Squeeze-film damping, Electrodes
Department/Centre:	Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	11 Sep 2020 07:48
Last Modified:	11 Sep 2020 07:48
URI:	http://eprints.iisc.ac.in/id/eprint/66480

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