NEITHER NIKOLA TESLA NOR JOHN GALT.

There's a lot of ambient electricity in the atmosphere.  Capturing it is another matter.  "Scientists have invented a device that can continuously generate electricity from thin air, offering a glimpse of a possible sustainable energy source that can be made of almost any material and runs on the ambient humidity that surrounds all of us, reports a new study."

Don't go looking for Galt's Gulch in Amherst any time soon.

Now, researchers at the University of Massachusetts, Amherst, have developed an Air-gen device that yields electricity from contact with water droplets that pass through its porous material. In this way, the Air-gen technology creates “a spontaneous and sustained charging gradient for continuous electric output” that “opens a wide door for the broad exploration of sustainable electricity from ambient air,” according to a study published on Wednesday in Advanced Materials.

“One day we may get clean electricity literally anywhere, anytime by using Air-gen technology (i.e., the concept of ‘ubiquitous powering’), because air humidity is 24/7 continuous and everywhere,” Jun Yao, an assistant professor of electrical and computer engineering at UMass Amherst and senior author of the study, said in an email to Motherboard.

In the way of research, this idea came about as a consequence of lessons learned pursuing a different line of research.

“The initial discovery was made back in 2020 and was really a serendipitous one—we found that Air-gen made from a specific material called protein nanowires synthesized by a type of bacterium called Geobacter can continuously produce electricity from air humidity,” Yao said.

“But that time, we considered the effect exclusive to this specific material (although we had some initial intuition/indication that the effect may expand to other materials as well),” he continued. “The current work is based on our initial intuition, which then leads to the discovery of this ‘generic’ Air-gen effect working with literally all kinds of materials. So it turns an initially narrow window to a wide-open door for broad potential/impact.”

Indeed, the results revealed that practically any material could become an Air-gen device provided it was perforated with tiny holes measuring 100 nanometers or fewer. At this scale, the holes are big enough to allow water to pass through an upper chamber into a lower chamber, but are small enough that the droplets make contact with the material as they move down through the holes. As a consequence, a charge imbalance is created in the device because the water droplets increase the charge of the upper layer by soaking it as they move into the lower chamber.

Don't hope to power your home computer, let alone your space heater, any time soon. "The microscale device was able to produce continuous energy equivalent to several hundred millivolts for a test period of a week, which is much longer than other air generator concepts that had a one-time power output that lasted no more than 48 hours." Scaling up is possible, but will it ever be commercially sensible?

“A general understanding is that the energy density is low (which can be intuitively understood that the air is very thin), so a single-layer of Air-gen has no way to compete with other power sources (e.g., solar, wind) for matched power volume,” Yao explained. “However, the beauty is that air is diffusive and filled in the entire vertical space, which means that we can stack many layers of air-gen devices in the vertical space to improve power (without taking up additional space footprint).”

“So in principle, Air-gen can be more space efficient” than other power sources, he continued. “Moreover, they can be engineered into varied form factors and neatly blend into the environment (even without one’s notice)” versus the example of “a solar panel that exclusively takes up space.”

I wonder what's involved in the special tooling to perforate material with such small holes, or if there's a way of doing the same sort of work with some sort of permeable membranes.