Electrically tunable and broader-band sound absorption by using micro-perforated dielectric elastomer actuator

• Main Authors: Lu, Zhenbo, Shrestha, Milan, Lau, Gih-Keong
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Article
• Language: English
• Published: 2017
• Subjects: Acoustic absorption; Elastomeric polymers
• Online Access: https://hdl.handle.net/10356/83352; http://hdl.handle.net/10220/42567
• Institution: Nanyang Technological University

Most membrane-type acoustic absorbers for low-frequency sound attenuation are applicable only at a fixed resonant frequency for a narrow bandwidth. Tuning of the acoustic absorption spectrum is desired to match the varying noises. This letter presents a micro-perforated dielectric elastomer actuator (MPDEA) to make a broader-band acoustic absorber electrically tunable. Voltage activation of the MPDEA reduces the membrane tension and hole size and thus enables the active shifting of the acoustic absorption spectrum. Such a membrane tuning method does not require discrete mechanical parts as for the cavity tuning method. Also presented are the analytical models to predict the voltage-induced hole size change and acoustic characteristics of MPDEA.