Have your ever seen those self-powered mechanical watches, those who charge themselves from your hand’s movement? They have one half of a heavier metal disc spinning around an axis. That movement rotates some wheels, who finally rotate the watch spring.
However, that is not our article’s subject. Our article talks about some newer discovery: some US researchers have created a nano-fiber textile that harvests the user’s movement energy. In the future, you can have clothes made of these fibers, it’s like wearing a continuously recharging battery.
Using the same mechanical principle as our self-winding watch described above, but on scale measured in billionths of a meter, these tiny nano-generators can scavenge “wasted” energy from sound waves, vibrations, or even the human heart beat. These fibers are covered with pairs of zinc oxide nanowires that produce tiny pulses of electricity in response to friction.
“The two fibers scrub together just like two bottle brushes with their bristles touching,” converting the mechanical motion into electrical energy, explained Zhong Lin Wang, the lead researcher from Georgia Institute of Technology.
In fact, the entire mechanism is based on the piezoelectric effect. Such devices, arranged in series, could produce a greater output. I guess cautions must be taken so they won’t electrocute the user.
The human body contains many sources of energy that could drive nanogenerators, including blood flow pumped by the heart, exhalation from the lungs, and walking.
Even the act of typing on a computer is a potential source of nano-scale energy.
So far, Wang and his colleagues have made more than 200 of the microscopic nano-generators. The fibers assemblies were each tested for 30 minutes to check durability and power production.
There remains at least one significant problem before these nano-fibers can become part of our daily wardrobes.
Zinc oxide is sensitive to water, which means that the clothes made from these fibers could never be washed! In the end, we don’t want “dirty” energy, don’t we? 🙂