In this project we want to formulate answers to some pressing research questions that currently exist around the development of meta-surfaces. We do this through three different but intrinsically connected objectives. First we study the physics of complex meta-surfaces where we replace the meta-atoms with meta-molecules. Then we develop an analytical formalism with which meta-surfaces can be designed for guiding surface waves. Finally, we broaden the functionalities of meta-surfaces by taking into account time-dependent material properties. The combination of these three objectives will provide us with fundamental insights from the improve the physical functioning of meta-surfaces and offer new perspectives for their applicability in the coming generation of photonic components.