Erwin Wilhelm Muller was a German physicist who invented the Field Emission Electron Microscope (FEEM), the Field Ion Microscope (FIM), and the Atom-Probe Field Ion Microscope. Erwin Wilhelm Müller was born in Berlin on June 13, 1911. 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. He received the National Medal Of Science in 1976. 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.