This Device Lets You Charge Your Phone on the Go Using Your Body’s Own Energy

The working principle behind HandEnergy is that of a two-axis rotor gyroscope. “You may be familiar with the wrist-training device called the Powerball, which is a powerful handheld gyroscope,” HandEnergy co-founder Alex Novik told Digital Trends. “We came up with the idea of putting a battery, metal coil and magnets inside a similar device for generating electricity. We spent a year developing it, trying to find the best materials we could. After around a dozen prototypes, we finally arrived at one that we were happy with.”

To use HandEnergy, users start by winding a starter ring. This transmits a signal to activate the rotor, at which point they can start rotating their wrists to keep the rotor spinning. It might sound hard to believe, but the rotor inside HandEnergy spins at an average speed of 5,000 rotations per minute, transmitting mechanical power to create an electric current, and charging the built-in batteries. To charge a device, all you have to do is hook it up to HandEnergy using a USB cable.