The Light Breeze You Make While Walking Causes This Small Device to Generate Usable Electricity

Like all animals, humans have evolved over millions of years to be incredibly efficient machines. Calories are plentiful and affordable in the Western world today, but that wasn’t always the case. Through most of our history as a species, calories were difficult to come by and so our bodies developed to use them as efficiently as possible. A typical person consuming 2,000 calories per day and maintaining their body weight is “powered” by the equivalent of roughly 100 watts — similar to a modern laptop. This small device harnesses our biological efficiency to generate electricity using the breeze we make while walking.

This device can create electricity in a breeze as slow as 3.6 mph, which is about what you can achieve with a brisk walk. That means that it will be constantly harvesting energy as you walk along, even if there is no wind at all that day. It turns our own natural efficiency into a means of generating power. It works best at wind speeds between 8.9 and 17.9 mph, but that is easily attainable on a windy day or when you’re riding a bicycle. Most importantly, this device is so light that it won’t add any noticeable resistance to your movement. It shouldn’t add any more drag than your own hair does, but can still provide enough electricity to light up some LEDs or power simple sensors. The technology has potential for powering wearable electronics, but can also be utilized on a larger scale.

This device is based on a triboelectric nanogenerator, which produces electricity in a way similar to how you can generate static electricity when you rub a balloon on your head. The triboelectric effect occurs when two materials with weakly bound electrons make contact and then are separated. In this case, the triboelectric nanogenerator contains two thin strips of plastic contained within a tube. As they flutter in a breeze, they repeatedly make and break contact with each other and generate electricity. Aside from powering electronics, this device could be scaled up and used in scenarios where traditional wind turbines aren’t practical. A large version of this triboelectric generator would cost less than a wind turbine and would work at slower wind speeds. It is, however, far less efficient than a wind turbine, and won’t replace that technology entirely.