It’s Electric

The newest source of renewable energy is here, and its power is contained in a device that is the size of a fingernail and thinner than a strand of human hair. What’s more, the source of that energy is endlessly abundant and all around us. In mid-2023, a team of engineers at UMass made national news when they announced that energy can be harvested from the humidity of air—and that the harvester they created, dubbed an “Air-gen,” can be made from nearly any material.

The team of engineers—Associate Professor Jun Yao and colleagues Xiaomeng Liu, Hongyan Gao, and Lu Sun—published their research in the journal Advanced Materials.

Here’s how their energy-harvest scheme works: A device containing a super thin layer of material is dotted with tiny pores that are less than a thousandth of the width of a single hair. The device allows water molecules in the air to pass from the upper part to the lower part of the material. The pores are big enough to allow water to pass through, but small enough that droplets make contact with the material as they move down. This creates a charge imbalance—the upper layer is soaked with charge-carrying water molecules while the lower layer has relatively fewer. This electrical imbalance produces a current, similar to what happens during the formation of lightning. These researchers have effectively found a way to generate a bolt of electricity—from just air.

This discovery has the potential to totally transform our approach to renewable energy. Not only is humidity omnipresent in our atmosphere (even the Sahara Desert has enough humidity to power the device!), but all sorts of materials—including wood and the cellulose found in the cell walls of plants—can be used to construct an Air-gen. “I call it a sustainable, continuous, and ubiquitous power solution,” Yao told The Boston Globe.

The next challenge for the team is figuring out how to scale this technology up further, so that it can be used to power small electronics or even homes. “What I envision,” said Yao, “is that sometime in the future, we can get clean electricity wherever we go.”