Flexible and large-area sound-emitting device using reduced graphene oxide

Large-area reduced graphene oxide (rGO) is demonstrated to emit sound for the first time. The whole device is flexible. The sound emission from rGO has a linear relationship with frequency in wide sound range (1 kHz ~ 50 kHz). It is suggested that the physic mechanism is fundamentally different from conventional loudspeaker and transducer. Theoretical simulations suggest that the mechanism is related to the thermo-acoustic effect. Due to the excellent characteristics of flexibility and large-area. the rGO sound-emitting device will open wide applications in multimedia, biomédical and many other fields.