Günter Sauerbrey
Günter Hans Sauerbrey (1 January 1933 – 15 May 2003) was a German physicist who invented the quartz crystal microbalance (QCM). Biography. Günter Sauerbrey obtained his Ph.D from the Technical University of Berlin. He was responsible of the Laboratory of Medical Techniques and Dosimetry of the Physikalisch-Technische Bundesanstalt (PTB) in Berlin for 24 years (from 1974 to 1998). Research contributions. Günter Sauerbrey invented the quartz crystal microbalance. He developed the research related to QCM in his doctoral thesis at the Technical University of Berlin and published it in two seminals papers in 1957 and 1959. He was  the first to use a harmonic acceleration field to measure mass, although he was not aware about this in the moment of publication. Together with the quartz crystal microbalance, he developed the Sauerbrey equation to explain the working principle of the device. Later, other authors developed derivative equations for different cases.