Solar torches may just be funny moments from movies, but in real life, there are too many torches that don't require batteries. Recently, a very powerful flashlight has been introduced, which is driven by differences in human body temperature and environmental temperature. It is practical and compact in size.

In fact, temperature power flashlights are not considered a black technology. Temperature power is generated through semiconductors, using temperature differences to obtain electrical energy. The basic principle of thermoelectric power generation is the "Zebeck" effect, which means that when two different metals are connected to form a closed circuit, if the temperature of the two connection points is different, a small voltage can be generated. At present, this temperature generator flashlight is in crowdfunding. It is made of aluminum or titanium alloy and weighs 35 grams and 45 grams. The aluminum alloy version is priced at $35, while the titanium alloy version is priced at $45.