Work

An Electret-Augmented Low-Voltage MEMS Electrostatic Out-of-Plane Actuator for Acoustic Transducer Applications

Year: 2020

Type: article

Abstract: 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 biased electret layer was fabricated at the inner surface of a silicon on insulator (SOI) structure facing a 2 μm gap owing to the high compatibility of silicon micromachining and the potassium-ion-electret fabrication method. A 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 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.

Source: Micromachines

DOI: 10.3390/mi11030267

Authors: Chikako Sano, Manabu Ataka, Gen Hashiguchi, Hiroshi Toshiyoshi

Institutions: Institute of Industrial Science, The University of Tokyo, The University of Tokyo, Shizuoka University, Research Institute of Electronics, Shizuoka University

Language: English

Topic: Advanced MEMS and NEMS Technologies

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,690

Funders: Japan Society for the Promotion of Science, Japan Science and Technology Agency, Core Research for Evolutional Science and Technology