Effects of the Number of Graphene Layers and Graphene Diaphragm Size on High Frequency Electrostatic Speakers

Graphene, a promising carbon nanomaterial, has garnered significant attention owing to its chemical stability, exceptional mechanical properties, and remarkable electrical conductivity and is being used in various electrical engineering applications ranging from solar cells to touch screens. The inherent mechanical strength and electric charge capacity of graphene enable efficient designs of diaphragms used in electrostatic loudspeakers, specifically within the high-frequency domain. This study incorporated single-layer and multi-layer graphene sheets, synthesized via chemical vapor deposition, as electrically charged diaphragms in electrostatic loudspeakers paired with an indium tin oxide film electrode to produce Coulomb force. Subsequently, the sound pressure levels of these distinct graphene- based electrostatic loudspeakers were determined through frequency response measurements. Based on our findings, we propose an optimal graphene film configuration for future electrostatic loudspeaker applications.