Smart Noise Control Using Shape Memory Sound Absorber

Efficient and satisfactory noise damping is essential for achieving a high quality of life. Therefore, the way of sound absorption is a very important technical issue in various industries such as automobiles, acoustics, naval architecture, and so on. In this paper, a unique sound absorber which could manipulate its geometry and resulting performance in an active fashion is demonstrated. The strategy is to adopt the reversible shape-changing ability of a shape memory polymer foam. The microstructure of foam is programmed and recovered in order to control the sound absorption capability dependent on frequency. The results reveal that the sound absorption coefficients could be tuned for the noise control based on frequency matching. Furthermore, the underlying theory is studied with a numerical simulation method regarding shape memory behavior and poroacoustical behavior. It is expected that the shape memory sound absorber proposed in this research provides a new insight into noise, vibration, and harshness technology.