I'll state for the purposes of prior art that, if you can get enough power to add a little fan or other air-moving mechanism to the circuit to pull air through the tube/heatsink, it will operate in still air for as long as a human can keep it warm.
This opens the mind to a realm of interesting body-powered devices, especially in environments where heat sinking is easy, like for divers, motorcycle riders, and sailors. Want a wetsuit or jacket that lights up or operates sensors on its own? Easy peasy.
I'll state for the purposes of prior art that, if you can get enough power to add a little fan or other air-moving mechanism to the circuit to pull air through the tube/heatsink, it will operate in still air for as long as a human can keep it warm.
This opens the mind to a realm of interesting body-powered devices, especially in environments where heat sinking is easy, like for divers, motorcycle riders, and sailors. Want a wetsuit or jacket that lights up or operates sensors on its own? Easy peasy.