Can electron microscopes record video of electricity?

Question

Since electron microscopes capture electrons, can they be used to capture electrons moving in a circuit, and have they been used for this?

Answer 1

It is possible to discriminate between voltages using a modified scanning electron microscope, provided the metal is exposed. Using sampling techniques on periodic waveforms high frequencies can be observed, discriminating voltage differences of the order of volts or even tens of mV.

More in this paper: https://doi.org/10.1016/S0065-2539(08)60199-7

Electrons at around room temperature are typically moving randomly extremely fast (~10^6 m/s) and only have a very slow average drift in the direction of current (a fraction of a mm/s) so direct observation of current flow is not likely practical.

Answer 2

You can't see individual electrons actually moving, but you can see the voltages on the surfaces of the circuit! Unfortunately, doing that destroys CMOS circuits over time due to the electrons slamming into the device and implanting charges in it where there shouldn't really be any charges.