What do penicillin, microwave ovens, pacemakers, Silly Putty, LSD, The Slinky, Post-It notes, X-rays, and inkjet printers have in common? They were all discovered by accident, usually by scientists investigating or intent on inventing something completely different. Now, scientists from the University of Massachusetts Amherst have a chance of joining the ranks of serendipitous creators by creating electricity out of thin air.
Xiaomeng Liu, a Ph.D. student working with electrical engineer Jun Yao and microbiologist Derek Lovley at UMass, discovered a way to generate electricity from the air. By accident, Liu found that exposure to atmospheric humidity generated an electrical current when protein nanowires contacted electrodes in a particular way. Liu was working on sensor development using nanowires created using a strain of the microbe Geobacter.
Lovley discovered the Geobacter microbe in 1987 in mud from the Potomac River. While working at Harvard, Lovley found that Geobacter can produce electrically conductive protein nanowires. At Harvard and later at UMass Amherst Lovley and colleagues explored making useful electronic devices Geobacter protein nanowires. So that’s what Liu was working on when he realized that the nanowires adsorbed water from the air. The adsorption held a thin film on the surface of the wires and produced a voltage gradient.
Further collaboration by Yao and Lovley resulted in a strain of E.coli that can be a “protein nanowire factory,” according to Lovley. Referred to as Air-gen devices, the UMass group continues to advance the technology. Air-gen technology is non-polluting, renewable, and low-cost, according to Lovley. The technology can produce electrical power in areas with any level of humidity, from desert to tropics.
The UMass group plans to scale up production of small Air-gen devices that can power smartwatches and other wearables such as health and fitness monitors. The next steps include creating enough power to charge smartphones and then eventually even in-home air generators for people who live off the electrical grid. The team hopes to make a major contribution to sustainable energy production. The team published a paper describing their invention in Nature.
