Active control cloak of the elastic wave metamaterial

The invisible cloak has attracted great attention due to its significant influences on science and engineering. Active elastic wave metamaterials provide superior controllable characteristics for the flexural wave cloak that is obviously different from the conventional structure. In this work, a broadband flexural wave cloak is designed and fabricated by the coordinate transformation method and active control system. The cloaking configuration consists of 16 alternative concentric layers with the polydimethylsiloxane (PDMS) and piezoelectric (PZT) patches which are connected with the active control systems. The results of the finite element simulations and experiments show that the effective frequency range of the flexural wave cloak with the active control systems is extended from 900 Hz to 1200 Hz. The design and fabrication of the elastic cloak with broadband characteristics have shielding applications.