Huh, you're right. I didn't know about that. From Wikipedia:
The Chinese startup claims to have the miniature device in the pilot testing stage. Unveiled in January 2024, it is allegedly generating 100 microwatts of power and a voltage of 3V and has a lifetime of 50 years without any need for charging or maintenance.
Wonder if it microwaves your balls when it's in your pocket too.
Either way we can dream of a future where we never have to plug in to charge again.
It's old tech actually. They use it in pacemakers because it's too difficult to replace or recharge the batteries. I guess you could do wireless charging now, but would you feel much safer with a lithium battery inside of you without a good cooling system? The body's internal temperature is surprisingly warm when you start doing the engineering.