Sound generation in voice frequency band by SMA actuators considering response characteristics

Abstract

This study aims to utilize SMA actuators as a sound source and to investigate the optimal driving method. Heated periodically by AC voltage with appropriate DC bias, the SMA actuator can vibrate and generates sound. In this paper, we investigated the relationship between the amplitude of input signals to the SMA actuator and generated sound. Based on the results of this experiment, we developed mathematical models to represent the input-output relationship of the SMA actuator. Using these models, we successfully flatten the frequency response of the SMA actuator to white noise.