A New Device Out of UMass Amherst Powers Small Electronics from Moisture in the Air
Researchers have developed a device that creates energy from moisture in the air. Using a natural protein, Air-gen connects electrodes with nanowires, forming a transfer pathway for electricity.
Scientists at the University of Massachusetts Amherst have unveiled new biotechnology that might be the answer for clean electricity. Coined Air-gen, the solution uses natural proteins to convert ambient moisture into power. These proteins are arranged into nanowire grids via Geobacter—a bacteria commonly found in soil and aquatic environments.
A depiction of UMass’ Air-gen technology, topped by an electrode. Image used courtesy of the University of Massachusetts Amherst
According to Sushmita Poddar and Surbhi Khurana's study on Geobacter, Geobacter has unique electron transfer capabilities that make it especially suitable within electronics applications.
How Does Air-gen Work?
Air-gen connects electrodes with nanowires, forming a transfer pathway for electricity. It can also operate 24/7. According to the researchers, this energy is "green," affordable, and renewable. These qualities are especially useful in portable electronics, which can't reap energy from wind or solar power.
“Solar energy requires sunlight, wind energy requires the wind,” said doctoral student Xiaomeng Liu in an interview with the Daily Hampshire Gazette. “But the moisture exists in our environment everywhere, so that means that our device can work everywhere and in the night.”
While wind and solar power depend on the energy-harvesting device being outdoors, Air-gen can operate both outdoors and indoors. According to a Nature article on power generation from ambient humidity using protein nanowires, past moisture-harvesting technology could only capture energy in brief bursts. This new solution is continuous.
Catering to Compact Electronics
How does the device's form factor play a role?
Each nanowire film is only 10 microns thick, saving precious real estate. Researchers plan to adapt Air-gen into a compact patch in hopes of replacing batteries in small electronics. This patch will work most effectively with consumer devices like smartwatches and fitness monitors.
Researchers revealed to the Daily Hampshire Gazette that Air-gen has excelled at powering small LED and LCD screens to this point. However, project leaders suggest these film layers can be daisy-chained to satisfy more robust power requirements.
The researchers claim that a working Air-gen prototype can power small LED and LCD devices. Image used courtesy of the University of Massachusetts Amherst
These devices are essentially always on, so anything mitigating the need for charging is highly desired. It’s also possible that Air-gen could include some long-term power storage solution akin to those in solar arrays.
Scientists will have to ensure these nanolayers remain flexible. This will protect conductivity pathways from acute and accumulated damage. Durability will depend on how these Air-gen components are arranged. Manufacturers will install nano-patches externally due to their dependence on environmental moisture.
Air-gen’s Commercial Ambitions
Smaller electronics will be ideal testbeds prior to commercial implementation. Surprisingly, this Air-gen leap is possible because of an accompanying E. coli breakthrough. E. coli produces many more protein nanowires than Geobacter. As a result, it allows companies to create sizable patches for complex applications.
While there are scalability questions to answer, UMass Amherst microbiologist Derek Lovley and electrical engineer Jun Yao are highly optimistic. Crafting nanowire layers from either microorganism represents a unique engineering challenge. If this technology can become ubiquitous, it may alleviate many environmental concerns, since clean energy remains a crucial talking point.
It appears that Air-gen isn’t the lab’s ultimate goal. Yao teases that numerous other protein nanowire applications have been developed, indicating innovations in nanowire electronics to come.
Does this device use up some chemicals over time?does it last forever?
The caption to the image states “A working Air-gen prototype generates ample power.” The picture, however, only shows that the device can drive the input of a 10M Ohm digital multimeter. That means it is delivering V^2/R = (0.544)^2/10M=30 nW. The meaning of the modifier “ample” is in the eye of the beholder but 30nW may not fit the bill for most designers. Nowhere in the article is there an indication of what kind of power the device is capable of. It seems to me that a safer caption is “... outputs 1/2 volt.”