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]