Touch-Programmable Metasurface for Various Electromagnetic Manipulations and Encryptions.

Abstract

Previous programmable metasurfaces integrated with diodes or varactors require external instructions for field programmable gate arrays (FPGAs), which usually rely on computer-inputs or pre-loaded algorithms. But the complicated external devices make the coding regulation process of the programmable metasurfaces cumbersome and difficult to use. To simplify the process and provide a new interaction manner, a touch-programmable metasurface (TPM) based on touch sensing modules is proposed to realize various electromagnetic (EM) manipulations and encryptions. By simply touching the meta-units of the TPM, the state of the diodes can be changed. Through the touch controls, the TPM can achieve independent and direct manipulations of meta-units and efficient inputs of coding patterns without using a FPGA or other control modules. Various coding patterns are demonstrated to achieve diverse scattering-field control and flexible near-field EM information encryptions, which verifies the feasibility of the TPM design. The presented TPM will have wide application prospects in imaging displays, wireless communications, and EM information encryptions.