Julius Edgar Lilienfeld (1881-1963) was born in Germany and emigrated to the USA in 1927.

Among other things, he invented the transistor and the electrolytic capacitor in the 1920s. He filed several patents describing the construction and operation of transistors. Although the devices described in his patents should theoretically work, there is no evidence that they actually did. Despite that, the patents describe many features of modern transistors. When the inventors of the first practical transistor, Brittain, Bardeen and Schockley tried to get a patent on their device, most of their claims were rejected due to the Lilienfeld patents.

Some of his patents:

• US1745175 (describing a device similar to a MESFET)
• US1900018 (A thin film MOSFET.)
• US1877140 (A solid state device where the current flow is controlled by a pourous metal layer, a solid state version of the vacuum tube.)
• US2013564 (The electrolytic capacitor)

External links

• About.com, short text about Lilienfeld
• J.E.Lilienfeld biography