German painter, sculptor, designer, and Kinetic artist, born at Wendorf, Mecklenberg. He studied at the Academies of Berlin‐Weisensee, 1949–53 (East Germany), leaving for West Berlin in 1955 and studying in Düsseldorf, 1955–8. In 1957 he began using nails in his work and most of his subsequent work has included them. His first nail paintings have been interpreted as political metaphors of the injuries inflicted by the Nazi era and the need for a new beginning. At first the nails were driven into panels—usually painted white—and then into various spatial constructions or existing objects such as chairs or a television set. The patterns of nails set up rhythms of light and shade, rather like wind passing through a field in sunshine. It was this quality of interaction between the art object and external light which first linked his work to Kinetic art, although he has subsequently made motorized and light sculptures. In 1961 he joined the Zero Group. His other work has included set and costume designs for opera. In 1999 he designed the prayer room for the Reichstag in Berlin. In 1974 he became a professor at the Düsseldorf Academy.