Progress, challenges, and perspective on metasurfaces for ambient radio frequency energy harvesting

In this paper, wireless power transfer (WPT) and energy harvesting (EH) technologies are reviewed in detail, and the application of metamaterials and metasurfaces for WPT and EH is discussed. Specifically, we focus on the metasurfaces for ambient radio frequency energy harvesting (AEH) in recent advances, comments, existing challenges, and future directions. The performance of metasurface- and antenna-based AEH systems is compared. The metasurfaces not only enable the efficient operation of the AEH system but also extend the potential function to various kinds of energy harvesting devices, which is influential progress of ambient electromagnetic energy harvesting.