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Scientist Uses Vegemite to Conduct Electricity

Australians love to eat Vegemite—and now, Marc in het Panhuis, a chemistry professor at Australia’s University of Wollongong, has discovered a whole new use for it: To conduct electricity. In the video above, you can watch in het Panhuis turn on an LED by using the yeast-extract spread to complete a circuit. Vegemite is a good conductor of electricity because it contains ions and water.

The whole thing might seem a little silly, but in het Panhuis and his team are working to create edible and 3D-printable hydrogels, which can be used to make things like medical sensors that gather data from within the human body, then disappear naturally when their job is done.

It's definitely a cool idea, though there’s still lots of work to be done before we get there. One big challenge: Scientists will need to figure out how to retrieve the data gathered by the sensors before they disappear.

The team had already been working with gelatin—the main ingredient of Jell-O—when they began testing with Vegemite. The main problem with hydrogels is that they're typically fragile. According to IEEE

[T]he group has found that using two different polymers, which form cross-linked molecular chains, makes the gels much more robust. For instance, they mix gelatin with genipin, an anti-inflammatory agent derived from the fruit of the gardenia plant. They also use gellan gum, a thickener used in pastries, sauces, puddings, jellies, and jams. For a crosslinker, they add common salts. Soaking the gellum gum hydrogel in sodium chloride—table salt—for seven days causes it to swell and become more mechanically stable.

The professor’s test led him to conclude, “The iconic Australian Vegemite is ideal for 3D printing edible electronics. It contains water so it’s not a solid and can easily be extruded using a 3D printer. Also, it’s salty, so it conducts electricity.” It even conducts electricity when it’s 3D printed on bread. Best of all, it’s still edible, and tasty—at least if you’re Australian.

[h/t Popular Mechanics]

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History
The Secret World War II History Hidden in London's Fences

In South London, the remains of the UK’s World War II history are visible in an unlikely place—one that you might pass by regularly and never take a second look at. In a significant number of housing estates, the fences around the perimeter are actually upcycled medical stretchers from the war, as the design podcast 99% Invisible reports.

During the Blitz of 1940 and 1941, the UK’s Air Raid Precautions department worked to protect civilians from the bombings. The organization built 60,000 steel stretchers to carry injured people during attacks. The metal structures were designed to be easy to disinfect in case of a gas attack, but that design ended up making them perfect for reuse after the war.

Many London housing developments at the time had to remove their fences so that the metal could be used in the war effort, and once the war was over, they were looking to replace them. The London County Council came up with a solution that would benefit everyone: They repurposed the excess stretchers that the city no longer needed into residential railings.

You can tell a stretcher railing from a regular fence because of the curves in the poles at the top and bottom of the fence. They’re hand-holds, designed to make it easier to carry it.

Unfortunately, decades of being exposed to the elements have left some of these historic artifacts in poor shape, and some housing estates have removed them due to high levels of degradation. The Stretcher Railing Society is currently working to preserve these heritage pieces of London infrastructure.

As of right now, though, there are plenty of stretchers you can still find on the streets. If you're in the London area, this handy Google map shows where you can find the historic fencing.

[h/t 99% Invisible]

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holidays
Custom-Design the Ugly Christmas Sweater of Your Dreams (or Nightmares)
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For those of you aspiring to be the worst dressed person at your family's holiday dinner, UglyChristmasSweater.com sells—you guessed it—ugly Christmas sweaters to seasonal revelers possessing a sense of irony. But the Michigan-based online retailer has elevated kitsch to new heights by offering a create-your-own-sweater tool on its website.

Simply visit the site's homepage, and click on the Sweater Customizer link. There, you'll be provided with a basic sweater template, which you can decorate with festive snowflakes, reindeer, and other designs in five different colors. If you're feeling really creative, you can even upload photos, logos, hand-drawn pictures, and/or text. After you approve and purchase a mock-up of the final design, you can purchase the final result (prices start at under $70). But you'd better act quickly: due to high demand, orders will take about two weeks plus shipping time to arrive.

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