Ok, so it looks legit, but its not really powered by “the air” its powered by radio waves. which when said that way sounds a lot more plausible.
100 micro Watts isn’t going to get you very far though.
even solar is more efficient than that. (which you could also say is power from “the air” I guess)
I have a friend who has experimented with this and yes it does work but the power is very small and we have only used it to power small text message monitering transmitters in remote locations where solar was not practical.