In this report we will introduce the notion of metamaterials for wireless power transfer (WPT). For that we will study the use of resonators in WPT and their advantages in respect to the simple induction based two coils WPT. We will study modal theory as a way for faster calculations of losses in the metamaterial and prediction of the resonant frequencies of the current in the secondary coil of the transformer. Finally, we will comment the results of a series of simulations conducted using the softwares Flux PEEC and Matlab.