Today in History – April 20, 1940 – RCA Demonstrates Scanning Electron Microscope (SEM). The history of the SEM begins in 1928 and RCA’s demonstration in 1940. In 1965 the first SEM was marketed by the Cambridge Instrument Company. The provided link includes an article that details the history of the SEM from 1928 to 1965. The author (McMullan), himself an important contributor to this field, traces developments such as the first attempts to image solids (Ruska 1933 and the more successful Von Borries 1940).He discusses von Ardenne’s 1938 highly magnified probe and Mahl’s 1941 transmission electron microscope (TEM).

The author speaks at some length about the Cambridge microscopes since this is where he worked with Oatley and added significant contributions to the field. Other contributors from around the world are detailed. Since this is an excellent article on the history of the SEM until 1965, added here will be a few contributions since that year.

An environmental scanning electron microscope, since it doesn’t need to operate in a vacuum like a standard SEM. Allows for the examination of almost any sample under any gaseous condition. Danilatos in the 1980s first used the term environmental SEM and the first commercial environmental SEM was produced by Electroscan.

In the 1990s Chumbley at Iowa State University, working with R.J. Lee Group, successfully created a remote, web-based control for a SEM. He calls this Project ExCel. This microscope allows pre-collegiate teachers to use the SEM in their classroom by remotely logging in to the SEM at Iowa State and controlling it over the internet. For more information, see the Engineering Pathway’seducational resources on SEMs and microscropy or view our Materials Engineering Education and our Ceramic Engineering Education community sites.

Also on this date in 1902 the Curies isolate radium and in 1964 the first picture phone is demonstrated. For more information, see the Engineering Pathway’s nuclear engineering, information technology and picture phones.