Watch this paper doll do sit-ups thanks to new kind of “artificial muscle”

Watch this paper doll do sit-ups thanks to new kind of “artificial muscle”

A new twist on a special kind of polymer is what enables this paper doll to do calisthenics.

A new twist on lightweight organic materials shows promise for artificial-muscle applications. Chinese scientists spiked a crystalline organic material with a polymer to make it more flexible. They reported their findings in a new paper in ACS Central Science, demonstrating proof of concept by using their material to make an aluminum foil paper doll do sit-ups.

There’s a lot of active research on developing better artificial muscles—manmade materials, actuators, or similar devices that mimic the contraction, expansion, and rotation (torque) characteristic of the movement of natural muscle. And small wonder, since they could be useful in a dizzying range of potential applications: robots, prosthetic limbs, powered exoskeletons, toys, wearable electronics, haptic interfaces, vehicles, and miniature medical devices, to name just a few. Most artificial muscles are designed to respond to

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Oldest evidence of cannabis smoking found in ancient Chinese cemetery

Oldest evidence of cannabis smoking found in ancient Chinese cemetery

Enlarge / This is how the braziers were placed in the tomb alongside the deceased. (credit: Xinhua Wu)

The broken wooden braziers, unearthed from 2,500-year-old tombs in Western China, contained burned, blackened stones, and the interior of the wooden vessels also looked charred. To find out what had been burned in them, University of Chinese Academy of Sciences archaeologist Yemin Yang and his colleagues used gas chromatography/mass spectrometry to analyze small samples of the charred wood and the residue from the stones.

Their analysis turned up a chemical called cannabinol, or CBN—an unmistakable chemical signature of cannabis. Those ancient chemical traces offer an important clue in the history of human drug use and the domestic history of cannabis.

In around 500 BCE, the ancient Greek historian Herodotus described people near the Caspian Sea gathering in small, enclosed tents to breathe in the smoke from cannabis burned atop a bowlful of

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Stronger than aluminum, a heavily altered wood cools passively

Stronger than aluminum, a heavily altered wood cools passively

Enlarge / A look at the lignin-free compressed wood. (credit: University of Maryland)

Most of our building practices aren’t especially sustainable. Concrete production is a major source of carbon emissions, and steel production is very resource intensive. Once completed, heating and cooling buildings becomes a major energy sink. There are various ideas on how to handle each of these issues, like variations on concrete’s chemical formula or passive cooling schemes.

But now, a large team of US researchers has found a single solution that appears to manage everything using a sustainable material that both reflects sunlight and radiates away excess heat. The miracle material? Wood. Or a form of wood that’s been treated to remove one of its two main components.

With the grain

Wood is mostly a composite of two polymers. One of these, cellulose, is made by linking sugars together into long chains. That cellulose is mixed with

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Superconductivity reported at the temperature of a good freezer

Superconductivity reported at the temperature of a good freezer

Enlarge (credit: Manmohan Singh | Getty Images)

Superconductivity offers the promise of hyper-efficient electric motors, ultra powerful magnets, and the transmission of electricity without losses. The reality, however, has fallen considerably short of that promise, as superconducting materials are difficult and expensive to manufacture, requiring a constant bath of liquid nitrogen to keep them cold enough to operate. And progress at identifying new high-temperature superconductors went through an extended stall, with no new contenders for decades.

But behind that stall, researchers were getting a better understanding of the physics involved with superconductivity, and that understanding seems to be paying off. A few years back, researchers found that a high-pressure form of hydrogen sulfide would superconduct at 203K (-70°C), roughly 65K higher than any previous material. Now, following up on suggestions from computer modeling, researchers have discovered that a metal-hydrogen compound (LaH10) can superconduct all the way up to

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