Transistor
The transistor is the fundamental building block of modern electronic devices, and is ubiquitous in modern electronic systems. Julius Edgar Lilienfeld patented a field-effect transistor in 1926 but it was not possible to actually construct a working device at that time. The first practically implemented device was a point-contact transistor invented in 1947 by American physicists John Bardeen, Walter Brattain, and William Shockley. The transistor revolutionized the field of electronics, and paved the way for smaller and cheaper radios, calculators, and computers, among other things. The transistor is on the list of IEEE milestones in electronics, and Bardeen, Brattain, and Shockley shared the 1956 Nobel Prize in Physics for their achievement.
Tom Kilburn
While Kilburn led one design team working on Meg, he led another with Dick Grimsdale and Douglas Webb, on a research project examining what he believed would be the next step forward in computer design: the use of transistors. The 48-bit machine they completed in November 1953 was the world's first transistor computer, with 550 diodes and 92 transistors, and was manufactured by STC. An improved version completed in April 1955 had 1,300 diodes and 200 transistors, and was sold by Metropolitan-Vickers as the Metrovick 950.