Moisture sensors started producing electricity, rather than just sensing moisture.
They seem to be making power from the transfer of charges in moisture in the air moving through a nano particle substrate.
So far, fairly small batteries have been made that can power an LED from moisture in the air!
Again, your old idea of nano transfer of charges, chips that actually make long term power by sorting electrons from surfaces that are out of balance… Even your Americium project… Many clues here… https://en.wikipedia.org/wiki/Hygroelectricity
Company making led battery: CastCataChuva