Scientists Generate Electricity From Nothing But Thin Air

In what could be a significant boost to the clean energy aspirations of the rapidly warming world, a team of scientists have successfully generated electricity from nothing but thin air. They used an enzyme from a common soil bacterium to transform atmospheric hydrogen into electrical currents. The work, published in Nature on Wednesday, offers the promise of a nearly limitless source of clean electricity.

Scientists have long known that bacteria can use trace amounts of hydrogen in the atmosphere as an energy source to help them survive in harsh environments such as Antarctic soils and volcanic craters. But until now, converting this gas to electricity has been a difficult task. But now a team from Australia’s Monash University has discovered an enzyme that can do just that. Combining the enzyme with protein nanowires produced by a sediment bacterium called Geobacter sulfurreducens could generate electricity from the air for over 20 hours. The researchers also connected multiple devices to increase the power output.

The process works by first trapping a DNA molecule in the bacterium’s membrane and then passing it through a nanopore made up of a hairpin adapter and molecular beacons complementary to the code units on one of its strands. Next, the DNA is sequenced as it passes through the nanopore, which gives the scientists a readout of the genetic information contained in the DNA molecule.

A second DNA strand is then passed through the hairpin adapter and molecular beacons to capture the opposite complement of the first strand, which allows the sequence to be reread. This gives the scientists a complete readout of the genetic information contained in the original molecule. The process also works for the reverse sequence — reading the complementary strand as it passes through the nanopore and then reversing the transcription to produce the original molecule.

Essentially, the device creates a flow of electric charges across the nanopore’s surface, generating a continuous current. This can power several circuits and devices, including LED lights, liquid crystal displays, and even a smartphone.

The team’s experiments suggest that, in theory, nearly any material can be turned into a device that continuously harvests electricity from humidity in the air. The key is peppering the material with nanopores less than 100 nanometers in diameter — a technique researchers call the “generic Air-gen effect.”

Jun Yao, an assistant professor of electrical and computer engineering at UMass Amherst and senior author of the study, tells Motherboard that the ultimate goal is to have the device work anywhere in the world in whatever weather conditions are present. The team is already working on an outdoor version that can be adapted to rainforest or desert environments. If successful, the ‘Air-gen’ device would be a universal power source since humidity is a constant around the globe.