Ruska, Ernst (1906-1988), a German electrical engineer, invented the electron microscope. In 1986, he was awarded half of the Nobel Prize for physics. The other half of the prize was awarded to Gerd Binnig of Germany and Heinrich Rohrer of Switzerland for their invention of the scanning tunneling microscope.
It had been previously demonstrated that electrons form configurations of waves similar to light waves, but with a wavelength of around 1 angstrom (1/10,000,000 millimeter). The shortest wavelength of visible light is about 4,000 times greater than this. Ruska therefore suggested that if a device were to focus waves of electrons as an ordinary microscope focuses light, objects could be observed in far greater detail. In 1931, he produced the first electron “lens,” consisting of an electromagnet that could focus a beam of electrons much as an ordinary lens focuses light. In 1933, Ruska created a more powerful electron microscope by using several such lenses together. See Electron microscope. .
Ernst August Friedrich Ruska was born in Heidelberg, Germany. From 1925 to 1927, he studied at the Technical University of Munich. He then entered the Technical University of Berlin. In 1937, he became a research engineer for Siemens, a leading electrical company. By 1938, this company made the first commercially produced electron microscope. From 1957 to 1972, Ruska worked as director of the Institute for Electron Microscopy, part of the Fritz Haber Institute of the Max Planck Society in Berlin.
