Invisibility concentrator for water waves

We theoretically design and experimentally demonstrate an invisibility concentrator, consisting of several truncated cylinders, for water waves based on a scattering cancellation method. The invisibility concentrator works by controlling the scattered waves from the target device. Our simulated and experimental results verify the concentration of waves and show the effective invisibility of the designed concentrator. This approach provides the possibility of simultaneously realizing wave concentration and an invisibility cloak, which has potential applications in energy harvesting.