Keeping devices charged while traveling, camping, hiking or participating in other outdoor activities is always a challenge. Although a solar charger is a good investment for such things, what happens if you find yourself somewhere without sunlight for a long length of time? Like, you know, the Arctic? Scientists at the Georgia Institute of Technology have what might be a better solution: a backpack that charges your devices using the energy you produce while walking.
The concept behind this backpack started with how static electricity works. When two oppositely charged surfaces come into contact and then separate, they release electricity. For example, when you walk across a carpet and then touch someone, they receive a shock. The backpack uses nano-generators to create a similar effect: one side of the backpack has aluminum film with microscopic holes, and the other has copper film with nanowires. These surfaces cover collapsible cards inside the backpack that are arranged in a rhombus shape. When you walk with the backpack strapped on, each step makes these cards collapse so that an aluminum-covered card touches a copper-covered one. This builds up a charge of electricity. When the cards return to their original position, they release the electricity.
When tested, this system generated over 1 watt of power, which doesn't sound that impressive, but it's just a start. Next, the research team will attempt to charge a lithium-ion battery, the same battery that most mobile devices use. They hope to expand the backpack to not only be a charging device, but also capable of sustaining an entire wearable computing system.
Via New Scientist