The days of having to carry a phone charger(充电器) everywhere could soon be over. Researchers from America have made great progress in getting energy from human motion(运动). They say smartphones could get enough power just by the motion of fingers on the screen.
The low-cost device(装置) has already been tested in an American university. Scientists successfully showed an LED touch screen, a total of 20 LED lights and a keyboard, all with a simple touching or pressing motion and without the help of a battery.
"What I predicted is the possibility of not having to charge your smartphone for a whole week, for example, because that energy will be produced by your motion," said one of the researchers.
The completed device is as thin as a piece of paper. Electrical energy is created when you press it. The device used to power the LED lights is the size of a hand while the device used to power the touch screen is as small as a finger.
The device will become more powerful when folded. Each time you fold it, the energy you create will be doubled. You can start with a large device, but when you fold it once, and again, and again. It's now much smaller, but it has more energy. It may be small enough to put in a specially made heel(脚后跟) of your shoe so it can create power each time your heel knocks the ground. The researchers are also developing technology that would send the power produced from the heel strike to an earphone.
