Swipe to charge! Radical 'nanogenerator' could charge your phone from the movement of a finger
The days of having to carry a phone charger everywhere could soon be over.
Michigan researchers have revealed a major breakthrough in harvesting energy from human motion.
They say it could lead to smartphones powered for a week by the motion of a swipe being harvested.
Michigan State University's low-cost device, known as a nanogenerator, has already been tested.
Scientists successfully operated an LCD touch screen, a bank of 20 LED lights and a flexible keyboard, all with a simple touching or pressing motion and without the aid of a battery.
The groundbreaking findings, published in the journal Nano Energy, suggest 'we're on the path toward wearable devices powered by human motion,' said Nelson Sepulveda, associate professor of electrical and computer engineering and lead investigator of the project.
密歇根大学电气和计算机工程系副教授及该项目的首席研究员纳尔逊 • 塞普尔韦达表示，这项突破性的发现，表明“我们正在向人体动作为可穿戴设备供电的研究方向发展”，这项发现已在《纳米能源》期刊上发表。
'What I foresee, relatively soon, is the capability of not having to charge your cell phone for an entire week, for example, because that energy will be produced by your movement,' said Sepulveda, whose research is funded by the National Science Foundation.
The process starts with a silicone wafer, which is then fabricated with several layers, or thin sheets, of environmentally friendly substances including silver, polyimide and polypropylene ferroelectret.
Ions are added so that each layer in the device contains charged particles.
Electrical energy is created when the device is compressed by human motion, or mechanical energy.
The completed device is called a biocompatible ferroelectret nanogenerator, or FENG, and is as thin as a sheet of paper.
The device used to power the LED lights was palm-sized, for example, while the device used to power the touch screen was as small as a finger.
Advantages such as being lightweight, flexible, biocompatible, scalable, low-cost and robust could make FENG 'a promising and alternative method in the field of mechanical-energy harvesting' for many autonomous electronics such as wireless headsets, cell phones and other touch-screen devices, the study says.
The device also becomes more powerful when folded.
'Each time you fold it you are increasing exponentially the amount of voltage you are creating,' Sepulveda said.
'You can start with a large device, but when you fold it once, and again, and again, it's now much smaller and has more energy.
'Now it may be small enough to put in a specially made heel of your shoe so it creates power each time your heel strikes the ground.'
Sepulveda and his team are also developing technology that would transmit the power generated from the heel strike to, say, a wireless headset.