Multifunctional Conformal Grayscale Electromagnetic Metamaterials

We present conformal grayscale metamaterials that encodes multifunctional electromagnetic responses for a broad angle and broad bandwidth in an arbitrary form factor. Pushing the limit in the material degrees of freedom, the metamaterial assumes a high contrast, grayscale dielectric constants varying at the subwavelength scale. Conformal form factor is realized by discretizing the device into irregular voxels. Extremely high performing devices are inverse designed via gradient-based optimization and fabricated via additive manufacturing. We demonstrate a suite of multifunctional wave manipulations at RF frequency, including dispersion engineering, beam forming and steering in an airfoil-shaped structure, and conformal carpet cloak.