Theory And Experiment Of Graphene-based Sound Device

Graphene membrane has excellent mechanical,electrical,thermal and optical properties.Its application in the field of electro-acoustic transducer is a research hotspot in recent years.The representative achievements are graphene electrostatic sound device(ESD)and graphene thermoacoustic device(TAD),which have wide application prospects in loudspeaker and ultrasonic transducer area respectively.The structure parameter plays an important role in the vocal performance of sound device.In order to obtain a better sound performance,it is necessary to grasp the influence of structure parameter on the performance of the device,based on which the optimization design of structural parameter could be conducted.However,existing research has not fully revealed the influence of graphene structure parameter on the vocal performance.In this regard,this paper conducts theory,fabrication and experiment research on graphene electrostatic and thermal sound device respectively.As a result,the influence regulations of graphene structure parameter on performance of the sound device are obtained,which is beneficial to the optimization design of graphene sound device.The main contents of this paper include:1.Theory analysis and Simulation of graphene sound deviceConsidering the structure parameters of graphene,the sound-pressure model is established for graphene electrostatic sound device.Based on the established model and existing thermoacoustic model,simulation is conducted to analyze the the influence regulations of thickness,size,stress and other structure parameters on the graphene sound device,to lay a theoretical basis for structure optimization design.2.Design and fabrication of graphene sound deviceA series of graphene electrostatic and thermal sound device with different structural parameters have been designed and fabricated.The manufacture process is focused on the graphene transfer technique,for which three transfer methods have been explored.The comparison among direct transfer method,stick transfer method and silicon assisted transfer method reflected that the third method is the most efficient and succeeded.3.Graphene sound device performance testing and comparative analysisAn acoustic platform has been built to test the performance of the graphene sound device.The comparison results have verified the effectiveness of the established sound-pressure model for graphene electrostatic sound device,and the influence regulations of graphene structure parameters is in accordance with the theory.As for thermoacoustic device,the influence regulation of graphene thickness has been confirmed.Besides,it is concluded that the suspended structure is better than backboard structure in sound pressure output.