Acoustic absorption performance of cavity-backed magnetoactive elastomer film

This work aims to investigate the acoustic absorption performance of magnetoactive elastomer (MAE) film, which consisting of carbonyl iron particles (CIPs) and polydimethylsiloxane matrix. MAE film is a kind of smart material. The magnetized CIPs can be forced to move when suffering from a non-uniform magnetic field, and finally, cause the morphology change of MAE film. The magnetic-dependent deformation of MAE film was investigated using the digital image correlation method. The result shows that the deformation is center-symmetrically distributed and increases with the growth of current. Increasing the CIPs content and the film thickness can enlarge the magnetic-dependent deformation of the MAE film. The maximum deformation of sample 4 (75 wt. % CIPs) under the current of 4 A is nearly 0.89 mm. Then, the acoustic absorption performance of cavity-backed MAE film was fully studied. For CIPs embedded cavity-backed MAE film, increasing the current can raise its maximum acoustic absorption frequency (MAAF). The MAAF of sample 4 changes from 2.33 to 2.88 kHz when the current rise from 0 to 4 A. Meanwhile, increasing the CIPs content and film thickness can effectively reduce the MAAF of cavity-backed MAE film. Moreover, reducing the film thickness can increase the maximum acoustic absorption coefficient of cavity-backed MAE film. With exceptional acoustic absorption performance, the MAE film can find extensive applications in intelligent control and acoustic absorption devices.