Journal Article
Buckling Dielectric Elastomer Transducers as Loudspeakers
Journal of the Audio Engineering Society · Volume 70 · Issue 10 · pp. 858–870 · October 2022
Abstract
In recent decades, dielectric elastomers (DE) have emerged as a promising transducing principle for various applications. They promise to be lightweight, efficient, and affordable alternatives to conventional electrodynamic or piezoelectric transducers and show large deformations at fast rates. In this work a loudspeaker concept is proposed, which relies on the elastic instability of a DE membrane. A multilayered DE membrane is clamped in a circular ring. Upon applying a DC voltage, its area increases, and themembrane buckles up. A superimposed signal voltage induces vibration and generates sound. To model the device mechanically, a system of partial differential equations is derived from Hamilton's principle. The mechanical model is then coupled to the linear assumed electrical and acoustical domains. Static, dynamic, and acoustic experiments on buckling DE transducers of three different diameters (10, 15, and 20 mm) and different thicknesses (0.4mmto 0.6 mm) as multilayer configurations are conducted to validate the model. Sound pressure levels of about 70 dB above 1 kHz are reached. Small loudspeakers like this may find application in mobile or array systems.
