Popcorn Might Be the Cheap, Biodegradable Robot Power Source of the Future

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iStock

If you've ever put a flat bag of kernels into the microwave and pulled out a full bag of fluffy popcorn two minutes later, you've witnessed a fascinating bit of food chemistry at work. Now, IEEE Spectrum reports that scientists are looking into applying the unique properties of popcorn to robotics.

For their study, presented at this year's IEEE International Conference on Robotics and Automation, Cornell scientists stuffed the movable parts of a robot (a.k.a. the actuators) with unpopped kernels of corn. Usually actuators are powered by air, hydraulics, or electric currents, but as the researchers found, popcorn works as a cheap single-use alternative.

When heat is applied to popcorn kernels, the water trapped inside them turns to steam, creating enough pressure to peel back the tough exterior and release the starchy endosperm. A sudden drop in pressure causes the endosperm to quickly expand, while the cool outside air solidifies it.

The results can be dramatic: When popping extra small white kernels, the cheapest popcorn tested, researchers saw them expand to 15.7 times their original size. Inside a soft robot, this amounts to building interior pressure that moves the actuator one way or another.

A similar effect can be achieved using air, and unlike popcorn, air can be pumped more than once. But popcorn does offer some big advantages: Using popcorn and heat is cheaper than building air pumps, plus popcorn is biodegradable. For that reason, the researchers present it as an option for robots that are designed to be used once and decompose in the environments they're left in.

You can get an idea of how a popcorn-powered robot works in the video below.

[h/t IEEE Spectrum]

Lítla Dímun: The Smallest of the Faroe Islands Has Its Very Own Cloud

While some islands are known for their unusual geography or unique history, Lítla Dímun is notable for its weather. The island, which is the smallest of Denmark's Faroe Islands chain, is often capped by a lens-shaped cloud, making it resemble a scene from a fairytale.

According to Mental Floss's own Kerry Wolfe writing for Atlas Obscura, the cloud floating above Lítla Dímun is a lenticular cloud. This type of cloud forms when moist air flows over a protruding geological feature, like a mountain top. When the wind moving up the landmass hits the air current directly above it, a sort of wave is created on the downwind side of the mountain. The moist air falling down this wave evaporates and then condenses into a large, flying-saucer-shaped cloud atop the mountain peak as a result.

Another factor that makes Lítla Dímun distinct is that it's the only one of the 18 main Faroe Islands without human inhabitants. Visitors to the mystical location will instead find a thriving population of sheep. Originally, Lítla Dímun was home to a group of feral sheep likely dating back to the Neolithic era. But they were hunted to extinction in the 19th century. Domesticated sheep were introduced there around the same time, and today, farmers visit the island once a year to round up their flocks.

One of the few signs of human life are the ropes farmers use to scale the cliff faces bordering the island. Even if you have rock-climbing skills, Lítla Dímun may be dangerous to visit. A boat ride to the rocky shore is only possible when the surrounding sea is calm.

[h/t Atlas Obscura]

Why Are Sloths So Slow?

Sloths have little problem holding still for nature photographers.
Sloths have little problem holding still for nature photographers.
Geoview/iStock via Getty Images

When it comes to physical activity, few animals have as maligned a reputation as the sloth. The six sloth species, which call Brazil and Panama home, move with no urgency, having seemingly adapted to an existence that allows for a life lived in slow motion. But what makes sloths so sedate? And what horrible, poop-related price must they pay in order to maintain life in the slow lane?

According to HowStuffWorks, the sloth’s limited movements are primarily the result of their diet. Residing mainly in the canopy vines of Central and South American forests, sloths dine out on leaves, fruits, and buds. With virtually no fat or protein, sloths conserve energy by taking a leisurely approach to life. On average, a sloth will climb or travel roughly 125 feet per day. On land, it takes them roughly one minute to move just one foot.

A sloth’s digestive system matches their locomotion. After munching leaves using their lips—they have no incisors—it can take up to a month for their meals to be fully digested. And a sloth's metabolic rate is 40 to 45 percent slower than most mammals' to help compensate for their low caloric intake. With so little fuel to burn, a sloth makes the most of it.

Deliberate movement shouldn’t be confused for weakness, however. Sloths can hang from branches for hours, showing off some impressive stamina. And because they spend most of their time high up in trees, they have no need for rapid movement to evade predators.

There is, however, one major downside to the sloth's leisurely lifestyle. Owing to their meager diet, they typically only have to poop once per week. Like going in a public bathroom, this can be a stressful event, as it means going to the ground and risking detection by predators—which puts their lives on the line. Worse, that slow bowel motility means they’re trying to push out nearly one-third of their body weight in feces at a time. It's something to consider the next time you feel envious of their chill lifestyle.

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