Hans-Jürgen Butt studies the structure and dynamics of interfaces. The aim is to better understand the relationship between structural changes, dynamics, and the driving forces. Major topics are interfacial forces and wetting, in particular wetting of superamphiphobic surfaces. His group investigates liquids that are internally structured at different length scales, such as polymer melts, solutions, dispersions, or emulsions. The methods used include scanning probe techniques, confocal microscopy, focused ion beam, microrheology, light and X-ray scattering. To expand the range of length and time scales accessible, new methods are continuously developed. Our goal is to solve fundamental questions, with the perspective of future applications.