Thirty years ago Seiko first unveiled the world's first kinetically charging watch; a watch that no longer needed battery replacements at regular intervals, and instead used a rechargeable battery inside that was charged via a complex set of gears and other mechanisms that moved with the human body throughout the day. Watches have evolved since then, and while sales and features of smartwatches aren't quite up to mass consumer standards just yet, time will likely be the thing that helps bring smartwatches more into the mainstream. One of the biggest issues people have with most smartwatches is their battery life. While it's easy enough to remember to charge your smartphone every night or give it a top-up throughout the day, it's not so easy to remember this for smartwatches, which often require special docks for charging.
New research is showing that triboelectric nanogenerators, or TENG, could be the key to making smartwatches entirely self-sustainable when it comes to battery life. Using a similar concept to what can be found in a kinetic luxury watch instead of old-fashioned gears, TENG motors stack two different sheets of material on top of each other, with a metal film attached to each sheet. The friction of these metal sheets rubbing together is then used to harvest kinetic energy and transferred to a rechargeable battery. The biggest hurdle for TENG is that the technology in its current state cannot provide enough power to charge a smartwatch while it's also being used. While this is an issue for now, it's one that will likely be rectified in the future.
The possibilities that TENG could bring to smartwatches are multifold, to say the least. Having a unit that's self-charging eliminates the need for any kind of dock or proprietary charger to be shipped with the watch, which in turn makes these watches significantly more green than they currently are. Also, users wouldn't have to worry about remembering to charge their watch or run out of battery at the worst possible time. A tertiary side effect could also be significantly smaller batteries, resulting in significantly smaller smartwatches, if the watch can sustain itself throughout the day's normal movements. TENG is certainly a promising breakthrough that could completely change the smartwatch industry, though only time will tell whether it manages to do so.