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Photo of Jörg Weißmüller

Prof. Dr.-Ing. Jörg Weissmüller,

Institute for Material Physics and Technology, Technical University Hamburg-Harburg, Hybrid Material Systems, Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung

Curriculum Vitae

Scientific Vita on his Homepage at TUHH
His Topic of Materials' Days 2011:

Novel functional materials based on nanoporous metals

Nanoporous metals prepared by the corrosion of an alloy can take the form of monolithic, millimeter-sized bodies containing approximately 10^15 nanoscale ligaments per cubic millimeter. The ligament size can reach down to the very limits of stability of nanoscale objects. The prospect of using alloy corrosion as a means of making nanomaterials for fundamental studies and functional applications has led to a revived interest in the process. One of the distinguishing features of nanoporous solids formed by alloy corrosion is their bicontinuous microstructure, with two contiguous and interpenetrating phases. When at least one of the phases—for instance, a gas in the void space—allows the fast transport of a signal, then the interfaces can be addressed and their properties manipulated. That predestines nanoporous solids as objects of study for a new class of functional materials, in which interfacial behaviour is controlled reversibly by external variables, and the entire material reacts. Nanoporous metal actuators or ‘metallic muscles’ exemplify that concept, as do photonic metamaterials with tuneable resonances and structural materials with tuneable strength and ductility. The quite distinct mechanical properties of nanoporous metals are of interest in themselves, since the relevant studies probe the collective deformation behaviour of macroscopic arrays of objects with dimensions at the lower end of the size scale.