We have designed a gradient-index (GRIN) metasurface to modulate water surface waves (WSWs). The metasurface is composed of an array of coiling-up-space units with a deep sub-wavelength scale. and can focus/scatter WSWs when the units are arranged elaborately and pierced into water. The modulation of WSWs has been ascribed to the relative effective refractive GRIN of the coiling-up-sp... https://thebrickes.shop/product-category/new-upload/