Wave field synthesis using buckling dielectric elastomer transducers

Abstract

This work presents a wave field synthesis (WFS) system using a novel loudspeaker concept based on dielectric elastomers. In WFS, large numbers of densely packed, individual audio channels are controlled to recreate arbitrary acoustic scenarios in the listener space, (i.e. listener zones in a room where different audio content can be radiated in different directions from the array, as seen in the supplemental material). Spatial resolution of the system increases with the increasing number of audio channels and with decreasing loudspeaker spacing. This motivates the use of buckling dielectric elastomer transducers (BDETs) as loudspeakers, which feature a simple setup, rendering them extremely thin and lightweight, and which promises ease of manufacture through the low demand on resources. In this work, a WFS system featuring 480 BDET has been developed. The prototype includes software, electronics, and the loudspeaker array. The electronical and mechanical design of the system is presented in detail. A nonlinear model based on the third-order shear deformation theory is applied to the BDET; the BDET is then experimentally assessed and compared to the model. Further, the final loudspeaker array is characterized by directivity measurements in an anechoic room to validate the reproducibility and quality of the setup. The presented technology highlights the structural advantages of smart materials over conventional transducers, which often are too large, heavy, and expensive for such array applications.