It Ain’t the Heat, It’s Humidity Powering an Eco-Energy Breakthrough

Moist air may friz your hair, but science can now use it for green energy, as well.

image via (cc) flickr user booleansplit

As we prepare to enter the dog days of summer, it’s probably best to remind ourselves that when it comes to excessively uncomfortable seasonal climates, “it’s not,” as the cliché goes, “the heat. It’s the humidity.” As it happens, that same turn of phrase is also the key to an exciting development in green energy that might one day help power some of our smaller gadgets and gizmos, using nothing but airborne moisture. Yes, the same abundant, and entirely free, humidity that makes the summer so unbearable may someday help power the very air conditioning that saves us from the heat.

In “Scaling up nanoscale water-driven energy conversion into evaporation-driven engines and generators,” published this week in Nature Communications, researchers lead by Columbia University’s Ozgur Sahin describe how they were able to utilize humidity to generate power for a number of specially constructed small devices. The key isn’t, as one might expect, tapping into the flow of water vapor as it moves through the air. Rather, the process hinges on a key biological reaction which naturally occurs in certain forms of bacteria when they are exposed to humidity: They expand.

Explains Science Mag:

Sahin and his colleagues used the living but dormant spores from Bacillus subtilis, a species of bacteria commonly found in soil and in the human gastrointestinal tract. Each spore typically swells and then shrinks up to 6% when moved from dry air to extremely humid air and then back again,

By thinly layering these bacterial spores in tandem across curved sheets of polymer, researchers were able to harness their natural expansion to straighten the sheet’s curvature, which then returns to its normal shape after the spores contract. When the bacteria works in tandem with multiple spores, the unit created is capable of expanding to nearly four times its ordinary length, resulting in a more dramatic back-and-forth motion for the polymer strip. It’s that motion which the team was able to then translate into modest amounts of mechanical power. Enough to spin a small rotary wheel:

Even (awkwardly) propel a lightweight vehicle:

That’s the good news. Unfortunately, Sahin and his team’s research is, for the time being, more significant as proof-of-concept than for any practical application. Still, it’s a promising development—even if it only works on a small scale—given the abundance of free humidity just waiting to be put to better use than simply frizzing our hair.

[via sciencemag]

via Michael Belanger / Flickr

The head of the 1,100-member Federal Judges Association on Monday called an emergency meeting amid concerns over President Donald Trump and Attorney General William Barr's use of the power of the Justice Department for political purposes, such as protecting a long-time friend and confidant of the president.

Keep Reading
via United for Respect / Twitter

Walmart workers issued a "wake up call" to Alice Walton, an heir to the retailer's $500 billion fortune, in New York on Tuesday by marching to Walton's penthouse and demanding her company pay its 1.5 million workers a living wage and give them reliable, stable work schedules.

The protest was partially a response to the company's so-called "Great Workplace" restructuring initiative which Walmart began testing last year and plans to roll out in at least 1,100 of its 5,300 U.S. stores by the end of 2020.

Keep Reading
via Rdd dit / YouTube

Two people had the nerve to laugh and smirk at a DUI murder sentencing in Judge Qiana Lillard's courtroom and she took swift action.

Lillard heard giggles coming from the family of Amanda Kosal, 25, who admitted to being drunk when she slammed into an SUV, killing Jerome Zirker, 31, and severely injuring his fiance, Brittany Johnson, 31.

Keep Reading