Design of Dielectric Elastomer Film Loudspeakers with X-shaped Structures

Conventional electromagnetic loudspeakers face challenges in miniaturization and lightweight design due to the constraints imposed by their magnet and coil structure. Accordingly, this study proposes a lightweight loudspeaker design based on thermoplastic polyurethane (TPU) dielectric elastomer films, which employs an X-shaped folded structure to generate sound through electric-field-driven film vibration. The influence laws of electrode materials (conductive silver paste, carbon paste), structural parameters, and driving voltage on the sound pressure level (SPL) and resonance frequency were systematically investigated. Experimental results demonstrate that the conductive silver paste electrode performed optimally at 400 V. Increasing the diaphragm diameter enhanced the overall SPL but slightly reduced the high-frequency response. A pre-stretching height of 20 mm produced the lowest resonance frequency, while further increasing the height improved the full-frequency SPL. Furthermore, the SPL exhibited a linear increase with the driving voltage. This research breaks through the lightweight bottleneck of traditional electromagnetic loudspeakers through an X-shaped structure design, providing key technical support for the practical application of dielectric elastomer loudspeakers.