Figure 11.

(a) Metagel filled with different media. (b) Filling different media proportionally in parallel channels. (c) The acoustic transmission coefficient of the metagel when filled with water, air, and liquid metal. The acoustic transmission coefficient (d) of the metagel when filled with water and air in different proportions. Experiment: (e). Simulation: (f). Adjusting the filling medium, the acoustic impedance of the metagel can achieve a wide range of matching. Reproduced with permission from [20].