Engineering query
So we all know in the analogue world you can get self-winding watches which harvest energy from the user moving around. And just yesterday I saw an old Tomorrow's World clip from 1981 about a thermocouple-powered watch.
How many Wh can you generate using such technologies in a watch? And how many Wh does a more conventional smart-watch use? Never mind how you store the energy in your battery, I just wonder how far apart these numbers are that we could ever conceivably see a self-'winding' smart watch? A fitbit that relied on the owner to exercise to keep it charged...
Biting the hand that feeds IT
