"An important frontier in condensed matter physics is the understanding of quantum materials in which different ground states compete, leading to electronic inhomogeneity and the concept of ‘quantum electronic liquid crystals’. The challenge for experiments is to measure the local electrodynamic properties in materials, which are electronically inhomogeneous, but atomically homogeneous.I propose a new technique to determine these local variations of the electronic properties. The central objective is to measure with nanometer-scale spatial resolution the frequency-dependent electrodynamic properties, such as complex dielectric constant and complex conductivity of quantum materials at frequencies in the several hundreds of GHz range. The method is derived from the recent progress in astronomical instruments for the submillimeter (hundreds of GHz to THz) frequency band. This progress, to which I contributed extensively, is driven by the desire to study the universe. Now, with this technology and expertise in hand, the disciplinary boundaries can be crossed once more and directed to the other challenging frontier of quantum materials. With this instrument it will become possible to determine the local (and possibly frequency-dependent) electromagnetic properties, such as the dielectric constant and conductivity, for a range of materials.Through this technique, I will make it possible to study the local properties of new materials and even to get access to the local energy-scales of their excitations. It is clear that the program is ambitious and risky, but if successful it provides a major step forward in experiments to reveal the various electronic states of quantum materials and a new scanning-probe technique operating in a new frequency range."