Your phone inevitably runs out of juice when you need it most, but soon your clothes could keep personal tech perpetually powered. Scientists have created a fabric that uses human movement, the wind, and the sun to charge electronics. Wearing a power t-shirt while you walk around all day could keep your smartwatch charged while you party all night.

This fabric that takes function in fashion to the next level was developed by material and environmental scientists from the Georgia Institute of Technology. They call it “a micro-cable power textile” and reported on it in Nature Energy on Sept. 12.

The power textile is the first to combine two ways of harnessing energy into a single fabric, using both mechanical (motion) and environmental (sun, wind) means according to a statement released by Georgia Tech. It’s also flexible, breathable, light, and adaptable, made from inexpensive and environmentally friendly materials—polymer fibers coated with metals and semiconductors—so it can be sustainably mass produced in the future.

The fabric is made by weaving together thin cables of fiber-based solar cells with fibrous nanogenerators. A single layer of the cloth is 320 microns thick, or .32 millimeters. By contrast, a cotton dress shirt of average thickness is about .25 millimeters, so the tech fabric isn’t that bulky. And the Georgia Tech team says it can be integrated into other fabrics to make clothing, curtains, tents, and maybe even sails.

The researchers tested the power fabric by making a flag about the size of a sheet of office paper (nine by 11 inches) and attaching it to a rod. The smart flag was flown out the window of a moving car on a cloudy day. Despite the weather, the experiment was a success, generating power (although how much precisely wasn’t specified). What it shows though, explained Zhong Lin Wang, co-author of the research and professor at Georgia Tech’s School of Materials Science and Engineering, is that the fabric “has a decent capability of working even in a harsh environment.”

Another experiment with a smaller swatch of smart fabric under ambient sunlight and using human motion also produced promising results: a four by five centimeter piece of power textile charged up a two milli-farad commercial capacitor to two volts in one minute. That’s not a lot of power New Atlas writes, but it could be enough to run small devices like a smartwatch.

You won’t be wearing smart sweaters this winter, however. There is still work to do to perfect the power textile. Next step: protecting the tech fabric from getting destroyed by non-energy-providing elements like rain and moisture.