Could tiny ‘wind turbines’ on our wrists kill off the phone charger?
TINY ‘wind turbines’ which strap to our wrists could spell the end of having to plug our phones into chargers, scientists say.
A team has developed a gadget which captures enough energy from the breeze as we swing our arms walking along to keep devices powered up.
The tool, called a nanogenerator, is made of two plastic strips which flutter and rub against each other, creating static electricity.
Researchers hope this could one day be harnessed to provide a cheap, endless power supply for portable devices. They also believe the technology could be used on a larger scale to replace inefficient wind turbines.
The scientists have been working on nanogenerators of varying sizes, some as small as a coin – although they think the devices can be made even smaller.
The two plastic strips become charged through a process called the triboelectric effect, working in much the same way as rubbing a balloon over your hair. They are effective with winds as weak as three and a miles an hour, although perform best at between 9mph and 18mph, when the strips flutter in sync.
In tests the nanogenerator, which is highly efficient at converting wind to energy, powered 100 LED lights.
The study’s senior author Dr Ya Yang, of the University of the Chinese Academy of Sciences near Beijing, said: ‘You can collect all the breeze in your everyday life. We once placed our nanogenerator on a person’s arm, and a swinging arm’s airflow was enough to generate power.
‘We have designed a nanogenerator as small as a coin, but we want to make it even tinier with higher efficiency.’
The researchers, who published their findings in the journal Cell Reports Physical Science, say they also aim to make a much larger device which can be used in areas where wind turbines are less effective, such as on land.
Dr Yang said: ‘I’m hoping to scale up the device to produce 1,000 watts so it’s competitive with traditional wind turbines.
‘We can place these devices where traditional wind turbines can’t reach. And unlike wind turbines that use coils and magnets, where the costs are fixed, we can pick and choose low-cost materials for our device.
‘It can also be safely applied to nature reserves or cities because it doesn’t have the rotating structures.’
The UK has more than 10,000 wind turbines, with each costing anywhere from £350,000 to £3million. While nearly 9,000 of the turbines are onshore, the offshore turbines are far more productive.