The more features a gadget packs, the faster the battery drains, which is why so many of us plug in every night. Matrix Industries’ PowerWatch tries to break that habit by running without a nightly charge.
Like something out of The Matrix, PowerWatch treats the human body as a power source. A thermoelectric generator turns body heat into electricity, so the watch tops up whenever it sits on your wrist. No wall outlet required.
Why doesn’t every device do this?
You might wonder why the same trick isn’t in every smart device. Thermoelectric generators need a temperature difference: the bigger the gap between the two sides, the more power they make. The body fights to stay near 37°C, so the skin-facing side of the watch warms up. The outer metal shell uses small heat sinks to stay cooler. That difference keeps a trickle of charge flowing.
The energy harvested this way is not enough to charge a phone, which is why body-heat charging fits a watch better than a handset. PowerWatch also drops features to live on that modest budget. You cannot, for example, mirror phone notifications on the watch.
Calories from body heat
One upside is calorie tracking. Because the device constantly reads temperature, it can estimate calories burned more convincingly than watches that lean only on heart rate, which is often a rough proxy.
PowerWatch pairs over Bluetooth, can check your time zone, and drops into a low-power mode when you are not wearing it. A small internal battery keeps the clock and date current.
Matrix Industries launched an Indiegogo campaign promising a PowerWatch in July next year for backers who pledge $170, and plans to show the product at CES in January.
