> Vacuum devices embedded in silicon!
Yeah yeah, nothing new.
What they have now is lamer than Edison's grey lamp or DeForest's earliest bottles. If this were the only amplifier around, it would take 30 years to get to a 6L6 or 12AX7. We do have other, mature, devices for nearly all applications, so it won't get the big investment. True, displays may drive improvement; but they have been saying that for 40 years and I ain't seen one at BestBuys yet.
And those geometries!!!! A type '10 tube is 100 times better geometry. What they got looks like Plate Input Grid Output abuse of a classic tube, except I'm not sure how the electrons are supposed to know which is which. The field emission types seem to run positive grid. Wonder if they know to check for grid current? Would be hard to notice, since plate current is vanishingly small and the grid would be similar. The one experiment tested enough to interpolate a Mu gives about Mu=3 (lousy geometry).
The "sound" of classic thermionic tubes is really about non-optimum geometry. Not bad geometry, just not intensely well coupled like a crystal junction. Here we have very wacky geometry in a process and scale that can NOT do the wires-and-tabs shape of classic tubes, not to mention that any big money will be in that field emission thing (ripping electrons directly out of a solid) instead of the wastefully gentle Thermionic Emission. FE seems to give a log curve, but I can't tell if it is anything like Child's Law.
If I had to bet between bleeding-edge research, and keeping Russian/Chinese bottle-blowers running, I'd stock-up on tube sockets.