Erwin Wilhelm Müller (or Mueller) (June 13, 1911 – May 17, 1977) was a German physicist who invented the Field Emission Electron Microscope (FEEM), the Field Ion Microscope (FIM), and the Atom-Probe Field Ion Microscope. He and his student, Kanwar Bahadur, were the first people to experimentally observe atoms. Life and work Müller was born in Berlin, where he studied at the Technical University under Gustav Hertz. He received his degree in engineering in 1935 and his doctorate in 1936. Müller worked at the Siemens Research Laboratory, where he invented the field emission microscope in 1936 that allowed resolutions of 2 nanometers. Müller married Klara Thüssing in 1939, and their only daughter Jutta was born in 1940. Due to the circumstances of war, he also worked at the Stabilovolt Company. In 1947, he was appointed to the Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry (renamed to Fritz-Haber-Institut on the occasion of its incorporation into the Max Planck Society in 1953) by Iwan N. Stranski. Here he developed the field ion microscope which, due to its resolution of 0.25 nm, was the first instrument used to observe atoms. In 1950, he took a teaching appointment at the Technical University in Berlin after finally having completed the required Privatdozent (habilitation). In 1951, he became professor at the Free University Berlin. Müller joined the faculty at Pennsylvania State University in 1952, where he remained until his death in 1977. He co-invented the Atom-Probe Field Ion Microscope at Penn State in 1967. He died in Washington D.C. Honors National Medal of Science (1977) Achievement Award of the Instrument Society of America (1960) Davisson-Germer Prize of the American Physical Society (1972) Carl Friedrich Gauß Medal (:de:Carl-Friedrich-Gauß-Medaille) (1952) John Scott Medal of the City of Philadelphia (1970) External Scientific Member, Fritz-Haber-Institut (1957) Honorary Degree, Free University of Berlin (1968) Honorary Degree, University of Lyon Medard W. Welch Award 1971 American Physical Society 1971 Selected bibliography Müller's first FIM paper. According to Melmed, "[this paper] provided the world's first view of the atomic nature of solid matter and began an entirely new field of study." References External links Erwin Müller at Penn State 1911 births Members of the United States National Academy of Sciences 1977 deaths 20th-century German inventors 20th-century German physicists National Medal of Science laureates Howard N. Potts Medal recipients