With a little help from bacteria, you can simply charge your smartwatch in the indoor or outdoor air.
This remarkable future scenario unfolds when you delve into the paper that was recently published in the Nature magazine. In the article, researchers say they have found a way to generate electricity using moisture that is simply in the air. It is a completely new technology that has numerous implications and is made possible in part by the very special bacterium Geobacter. The microorganism naturally produces conductive nanowires that the researchers use to generate electricity from nothing.
It was Lovley himself who discovered the Geobacter microbe more than thirty years ago in the mud of the Potomac River. And now we know that the bacteria is anything but rare. “Geobacter is a common inhabitant of soil and sediments,” said Lovley. “The bacteria is – just like many other bacteria – rod-shaped, but produces electrically charged protein nanowires.” These nanowires enable the bacteria to make contact with the environment in a unique way. And so researchers also see other options for those nanowires …
How does it work?
First of all, the nanowires that Geobacter makes are taken from the bacteria. “So there are no further bacterial cells involved,” researcher Derek Lovley told. Many of those nanowires are then placed on an electrode as an ultra-thin layer of material. “And a smaller electrode is placed on the nanowires. The nanowires then absorb moisture that is in the air (and naturally has a charge, ed.). The top side of the layer of nanowires becomes wetter than the bottom side, so that there is a charge trend in the layer of nanowires and therefore a difference in voltage between the two electrodes. Continuous exposure to the air is needed to generate electricity. “
The researchers have named their special generator Air-gen. For now it is only a small generator that can also supply very modest amounts of electricity. “The generator can only power small electronic devices,” says Lovley. “The fact that the generator is so small has to do with our limited supply of nanowires. It is difficult to grow large amounts of Geobacter . ” Fortunately, Lovley and colleagues came up with something. “We have recently solved this problem by genetically modifying an E. coli strain (a bacterium that can easily be grown, ed.) So that it generates nanowires. Now that we have more nanowires, we can make the devices larger and therefore also generate more power. “
In the desert
In addition to sufficient nanowires, the generator therefore also needs moisture. But not so much, Lovley emphasizes. This also makes it work indoors and even in the desert. “The humidity inside and even in the desert is large enough to make the generator work.”
The options for Air-gen are endless. Researchers see it as a great solution for charging small electronic devices, such as a smart watch. For example, they are already thinking of developing an Air-gen sticker that you can simply stick on the device and then provide the device with continuous energy. But scaling up the technology also offers possibilities. “The ultimate goal is to make large-scale systems,” says researcher Jun Yao. “For example, the technology can be processed into wall paint that provides your house with energy. Or we develop stand -alone air-powered generators that are off the gridcan supply electricity. As soon as we can make the wires on an industrial scale, I absolutely expect that we can build large systems that make an enormous contribution to sustainable energy production. ”