考虑基底热传导的石墨烯薄膜热声理论

Thermo-acoustic theory of graphene films considering heat transfer of substrate materials

主要基于热声效应对石墨烯薄膜发声进行理论研究。首先建立了石墨烯薄膜耦合热振动模型,推导出了石墨烯薄膜发声器的声压表达式。在此基础上,进行了不同基底石墨烯薄膜发声器的声压测试,并将测试值与理论计算结果对比,二者随频率变化趋势基本吻合,测试值略低于理论值,验证了推导出的声压表达式的正确性。研究表明石墨烯薄膜发声器有很宽的频域响应,在低频段声压级随频率增大而增大,在高频段响应平稳,具有作为优秀的热致发声器的潜力。基底材料蓄热系数越小,石墨烯薄膜的声压值越大;声压级随薄膜热容量的增大而减小。研究结果对于石墨烯的发声机制探索及其在扬声器设计等方面的应用具有指导意义。

Based on the thermo-acoustic theory, a coupled thermal-mechanical model for graphene films is established,and accurate analytical solutions for thermal-acoustic radiation from a graphene thin film is obtained. The sound pressure of the graphene film generator based on different substrates is measured, and the measured values are compared with the theoretical results, the tendency with frequency of experimental results is consistent with the theoretical values,the measured values are slightly lower than the theoretical values. Accuracy of theoretical model is verified. Studies have shown that thermal-acoustic radiation from a graphene thin film has a very wide frequency response. In the low frequency sound pressure level increases with the frequency, the acoustic pressure varies smoothly with frequency In high frequency. Thus it can be used as excellent thermal generator. The thermal effusivity of the substrate is smaller, the sound pressure of grapheme films will be higher. Furthermore, the sound pressure decreases with the increase of heat capacity per unit area of grapheme films. Results will contribute to mechanism research of graphene films generator and its application in the design of loudspeaker and other areas.