Research on sound pressure level of graphene loudspeaker with AC and AC/DC excitation

Abstract

In this work, a graphene loudspeaker is designed using laser scribing technology, and its theoretical model with AC and (AC + DC) excitation is established, which focuses on the effect of different excitations on the performance of graphene loudspeakers. The proposed theoretical model consists of a temperature gradient model and a sound pressure model. The application of (AC + DC) excitation helps to mitigate the frequency doubling effect caused by AC excitation. Sound pressure level (SPL) measurements with AC and (AC + DC) excitations are carried out to verify the theoretical model. The measured results show that the SPL is proportional to the input power and inversely proportional to the measurement distance. The highest SPL produced by the graphene loudspeaker is 53.3 dB with (5 VAC + 5 VDC) excitation. The theoretical model of the graphene loudspeaker with different excitations has a certain reference value for further research on thermoacoustic effects and improving the efficiency of graphene loudspeakers.