Nanowerk November 27, 2024
Lightweight, low-cost metasurfaces and reflect arrays that are easy to stow and deploy are desirable for many terrestrial and space-based communications and sensing applications. A team of researchers in the US ( Columbia University, North Carolina State University, City University of New York) demonstrated a lightweight, flexible metasurface platform based on flat-knit textiles operating in the cm-wave spectral range. By using float-jacquard knitting to directly integrate an array of resonant metallic antennas into a textile, two textile reflect array devices, a metasurface lens (metalens), and a vortex-beam generator were realized. Operating as a receiving antenna, the metalens focused a collimated normal-incidence beam to a diffraction-limited, off-broadside focal spot. Operating as a transmitting antenna, the metalens converts the divergent emission from a horn antenna into a collimated beam. The vortex-beam generating metasurface produced a focused vortex beam with a topological charge over a wide frequency range. Strong specular reflection was observed for the textile reflect arrays, caused by wavy yarn floats on the backside of the float-jacquard textiles. According to the researchers their work demonstrated a novel approach for the scalable production of flexible metasurfaces by leveraging commercially available yarns and well-established knitting machinery and techniques… read more. TECHNICAL ARTICLE