Self-powered hydrogen sensors

Nano World: Self-powered hydrogen sensors

Nanotechnological, inexpensive sensors that can detect invisible, odorless hydrogen leaks and sound the alarm wirelessly could help safeguard future vehicles and refueling stations based on the gas, experts told UPI’s Nano World.
Intriguingly, the sensors have the ability to power themselves by harvesting energy from slight vibrations. This means they could operate continuously without batteries or maintenance when affixed to cars, refrigerators, pumps, motors or any other vibrating machine, the researchers added.

The chemical reaction hydrogen cars run on is remarkably simple. Just combine hydrogen gas with oxygen and you get energy and water — and none of the dirty mix of toxins and global warming gases burning gasoline spews forth. The cleanliness of hydrogen is in large part why government and industry support for hydrogen vehicles has reached into the billions of dollars.

The problem is hydrogen is odorless, invisible and potentially explosive. Researchers at the University of Florida at Gainesville funded by NASA have developed hydrogen sensors designed to work together in the dozens or hundreds to overcome this hurdle.

You will need to have sensors all over the place — if there is a leak, you can see which ones light up, and where the leak is, and how quickly it is spreading. That way you can shut off valves and avoid a major problem,” said researcher Steve Pearton, a materials engineer.

The sensors, currently the size of a deck of cards, employ rods of zinc oxide only nanometers or billionths of meters wide coated with platinum catalyst. Extremely tiny electrical currents are passed through each rod, and the more hydrogen surrounds these whiskers, the more conductive they become, to effectively detect hydrogen in the air. The researchers also developed wireless transmitters to broadcast signals out from the sensors, as well as ways to power the devices either through conventional solar cells or piezoelectric energy harvesters that convert vibrations into electricity.

You need lots of hydrogen sensors to detect leaks, but you don’t want to have to maintain them or change the battery every couple of months,” said researcher Jenshan Lin, an electrical engineer. “Our sensor can operate completely independently