Viscoelastic Response of Graphene Oxide-Based Membranes and Efficient Broadband Sound Transduction

Freestanding micrometer thick graphene oxide (GO) membranes combine high stiffness, low mass density, and high loss coefficient. This unique combination of properties is ideal for efficient and broadband electro-acoustic transduction, relying on membrane lightness, stiffness, and internal damping. Here, the viscoelastic response of GO membranes is measured, and the application of approximate to 100 mu m thick GO membranes is demonstrated in dynamic loudspeakers. Using dynamic mechanical analysis and the time-temperature superposition principle of polymer rheology, it is found that the stiffness of GO membrane increases by more than 50% over 1-20 kHz while damping decreases by less than 20%. GO membranes exhibit 45% higher damping than aluminum membranes in loudspeakers assemblies. Consequently, GO membranes enable the upshift of loudspeaker breakup frequency by 16 to 12 octave above speakers assembled with aluminum, polyethylene terephthalate, titanium, and oak wood membranes. GO is thus found to be an exceptional material for electro-acoustic transduction.

Automated summary

GO membranes with high stiffness, low mass density, and high loss coefficient are ideal for efficient and broadband electro-acoustic transduction. The viscoelastic response of GO membranes and their performance in dynamic loudspeakers demonstrate their superiority over aluminum membranes.