Tube🌿Timethis is a Nuvistor! it's a super-advanced vacuum tube that could have beaten the transistor.
in 1959, RCA took their tube-making expertise and made this micro miniature tube almost as small as a 1950s transistor
RCA developed all new equipment to make it. this machine seals a batch of Nuvistors automatically!
in the 1950s, tubes still had advantages over transistors -- they even lasted longer!
so how did they miniaturize the Nuvistor? time to cut one in half. check out the cross section!
i'd annotate my photo, but RCA published a really nice cutaway diagram, so i will show you that instead.
Nuvistors found their way into some high end applications but transistors surpassed them in a few years, and they just faded away.
fascinating to imagine an alternate reality where transistors never worked and people figured out how to miniaturize vacuum tubes, etching arrays of them on metal wafers and building computers. In fact, they could even have built the entire Internet using a series of tubes.
Trammell Hudson@tubetime the Vacuum Transistor allows fabrication of chip-scale vacuum tubes on normal CMOS process. These devices switch in the terrahertz range and require neither a heated filament nor a vacuum, since the source-to-drain distance is shorter than the mean free path (which means electrons won't hit any other atoms along the way): https://spectrum.ieee.org/introducing-the-vacuum-transistor-a-device-made-of-nothing
Marc Jacobs@th @tubetime The article is from ~10 years ago.
I did a search after reading and it seems like these two scientists at Ames are doing most of the publishing on the subject.
Fascinating stuff, especially for TeraHertz radios. Would love to see this commercialized.
Side note: at my first job, we used vacuum tube RF supplies in plasma etchers, to make 0.9 um CMOS. Metal can triodes.