This book presents an innovative concept for the realization of sensors based on a planar metamaterial microwave array and shows their application in biomedical analysis and treatment. The sensors are able to transduce the dielectric properties of materials in their direct vicinity into an electric signal. The specific array organization permits a simultaneous analysis of several materials using a single readout signal or a relative characterization of one material where information about its spatial distribution can be extracted. Two applications of the designed sensors are described...