The PowerWatch is a rugged aircraft-grade aluminium smartwatch that wirelessly syncs with your smartphone, automatically adjusting to current time zones and has changeable watch faces. The watch is also water resistant to 50m so is perfect for swimming.
PowerWatch measures calories burned, activity level and sleep using advanced thermoelectric technology. It’s also the only watch to feature a power meter which displays how much electrical power you are generating. The thermoelectric technology behind the watch converts heat to electric power. Based on the Seebeck effect discovered in 1821, in the absence of an applied voltage gradient, electric current can still be generated if there is a temperature gradient. NASA has used similar technology to power the Voyager spacecraft and Curiosity, the mars rover.
You never need to recharge the watch; when it’s taken off, your data is stored in memory and it effectively goes to sleep. Put it back on and the watch comes to life right where you left it. Source: – The world’s first smartwatch powered by body heat