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Watch bacteria power adorably tiny engines

The future of clean energy is an incredibly exciting one: we will do more while protecting the environment. Countless researchers, private institutions, public universities, companies, and government agencies are working to get us there, so let's take a look a one such project from ExtremeBio, a group of scientists affiliated with Columbia University, which came up with a fun way to power small engines using microbes that just happen to live inside you, too.

These microbes are tiny, adorable energy sources

Bacterial spores B. subtilis exist in harsh places: they live not only in the human body safely (and are in your stomach right now), but also in other harsh environments like deserts. The microbes expand when they absorb moisture, and they contract when they dry.

Cute B. subtilis spores.

ExtremeBio

Here's a brief animated primer on them from ExtremeBio, in 2014:

B. subtilis are great candidates energy sources in drier climates — the kinds of places where solar energy works well, too.

These spores really love teamwork

Researchers dotted strips of tape with the spores:

The journey of a microbe, moving from tube to tape.

ExtremeBio

The individual microbes all work in the same way, so when one grows bigger because the air is more humid, they all grow, and the tape expands with them. When the air is drier, the spores shrink and the tape contracts:

Spore-coated polyimide tapes at various humidity levels — the longer the strip of tape, the higher the humidity level.

ExtremeBio study, Nature.com

Put the tapes together to make tiny engines

The researchers made two prototypes to display how the microbial movement acts as an energy source. Since these sports are relatively safe for use, I immediately thought of their use to make science-related toys like cars, planes, and boats for kids everywhere.

Device #1 looks like the sails on a boat:

ExtremeBio

Here are the tiny sails expanding and contracting, which pushes thin, clear rods on the right side of the engine. The rods could, presumably, be attached to a rudder, wheel, or other device that could be controlled to steer or direct a machine...

ExtremeBio

...or, if desired, transfer these tiny energy suppliers into sources of electricity. Device #2 looks sort of like a traditional watermill:

ExtremeBio

Imagine this microbe mill working in the desert using evaporation, or as a tiny engine attached to small wings on a toy plane or flying device (with a camera, perhaps):

ExtremeBio

Here the wheel is on a small platform, pushing a little "car" along:

ExtremeBio

You can watch the full video below, or read the full study here.

More research is needed before applying their use, but microbe engines are fun 

We're far off from considering microbes as a powerful source of energy on the level of solar power. However, there's a possibility that microbes could work hand in hand with solar, since the two exist outside. They are both exposed to the elements, and the heat of the sun triggers evaporation after rain.

Microbes show us that the future of clean energy is bright — and possibly humid.