The research paper…notes that the human body is particularly efficient at generating 40 MHz RF energy. Tapping into that through a 'worn receiver' provides power without using any invasive means.
But I read much of the pdf linked at the bottom of that link, and there’s nothing about the human body generating energy at 40MHz. The trick is that skin is pretty effective (sort of) at conducting energy at that frequency, so the authors hooked up a power transmitter worn on the forearm, 5 or 15cm away from a receiver on the hand.
This isn’t about powering anything by body energy, it’s about strapping a battery-powered transmitter somewhere on your body and then having another device pick it up when strapped somewhere else on your body. No thanks.
Oh and it’s actually pretty inefficient and won’t provide much usable energy.
Is it only through the skin? I could see it being useful for some sort of implanted medical device/monitoring system.
That way you have something subcutaneous but the power source is strapped to the outside of your body so you can remove for short periods of time to wash/recharge it.
Power isn't harvested from the human body it's transmitted (in really small amounts) across the body from one device to another, using capacitive coupling and 40MHz AC voltage.