Fig. 17: Flexible audio-emitting and audio-receiving devices based on nonsuspended graphene.

a Transparent and flexible graphene-based sound sources, including monolayer graphene on PET and a schematic of the acoustic measurement²⁹². b Wafer-scale flexible graphene earphones and an SEM image of laser-scribed graphene and graphene oxide²⁰⁶. c An intelligent artificial throat with sound-sensing ability based on laser-induced graphene²⁹³. Figures reproduced with permission from refs. ^206,292,293