The goal of this project is the achievement of sharp dynamic (i.e., time dependent) reflecting/refracting interfaces in metamaterials. Metamaterials are artificially structured materials, designed to interact with electromagnetic waves, and whose structure has feature size well below the wavelength. This implies that the detailed structure is not resolved in the interaction, and the material behaves as a homogeneous medium to the wave. Thus one can fabricate materials with properties that are not found in natural materials. Most known examples are metamaterials that exhibit simultaneously a negative real part of dielectric permittivity and a negative real part of magnetic permeability for a designed range of electromagnetic wavelengths. In this project, however, we aim at achieving fast and large tunability of permittivity in real time. This will let us generate dielectric refracting and reflecting dynamic interfaces. The difference from the known phenomenon of reflection and refraction is that here we can move these interfaces, and - importantly - with no true mechanical motions of media. Absence of mechanical motions allows for potentially very high speed "movements", making this an enabling technique to observe intriguing phenomena, such as photonic energy lifters, strong Doppler shifts, wavelength converters, and, potentially, event horizons and emission of Unruh radiation. The work will be performed at Harvard University (USA) for the outgoing phase (12 months), and at the Università degli Studi di Trento for the return phase (12 months).