Rheology is the science of deformation and flow of materials. Within this publication a sensitive method for non-linear theological characterization, Fourier-transformation rheology, will be presented. The application of the FT-rheology is not related to a specific class of materials, it is a rather general method. Currently one focus of non-linear methods is towards the interplay of topology and material properties and the investigation of phase separating systems. Additional, thickeners and food have been investigated. Furthermore, FT-rheology allows the quantification and prediction of fatigue of materials. (C) 2010 Elsevier B.V. All rights reserved.