Tunable Hybrid Acoustic Metamaterials for Structural Health Monitoring

Metamaterials technology offers new possibilities for wave imaging and for the control of propagation of wave at subwavelength scales. Acoustic metamaterials can manipulate elastic waves in ways that are not possible in conventional materials. Despite much progress in the development of metamaterial subwavelength designs in both optics and acoustics, the extension of this concept to the beam-forming and beam-steering in Structural Health Monitoring has not been attracted much attention. For Structural Health Monitoring perspective, using acoustic metamaterials are more suitable due to the flexible focused and steerable excitation and not need complexity transducers required by phase array technology. Here, we report the demonstration of a tunable hybrid acoustic metamaterial. The proposed concept is based on the design of dynamically tailored structural elements via embedded combination resonant and non-resonant structure. Such a tunable hybrid acoustic metamaterial can provide novel and important functionalities for manipulating the lamb wave and expand their application in Structural Health Monitor- ing.