If you tend to be a bit clumsy with your tech devices, there’s positive news on the horizon for you: scientists have invented a remarkable electricity-conducting material that toughens up as you hit it.
Researchers at the University of California, Merced, have reported on a soft, flexible material with “adaptive durability,” meaning it gets stronger through impact.
The new material also conducts electricity, so it shows promising opportunities for electronic wearables like smartwatches or personalized medical sensors.
Researchers presented their results on March 20 during the spring meeting of the American Chemical Society (ACS), a hybrid event that features nearly 12,000 presentations on a range of science topics.
Scientists have invented a flexible, electricity-conducting material that gets stronger through impact
Image credits: ThisisEngineering
The inspiration for the newly developed material came from a mixture you may find in your kitchen cabinet and is commonly used to thicken stews and sauces: cornstarch.
When you add water to cornstarch, the mix is soft and can be stirred easily. However, when you hit the surface fast, the mixture gets strong and acts like a solid.
“When I stir cornstarch and water slowly, the spoon moves easily,” explained Yue (Jessica) Wang, a materials scientist and the project’s principal investigator.
“But if I lift the spoon out and then stab the mixture, the spoon doesn’t go back in. It’s like stabbing a hard surface.”
They hope to use the newly created material for smartwatches, flexible electronics for health monitoring, and 3D printing of personalized electronic prosthetics
Many substances change states (from solids to liquids to gasses) when you change the temperature, such as freezing water into ice or boiling it away into steam. But, in the case of cornstarch slurry, it’s actually the changes in pressure, instead of temperature, that change its properties.
Scientists sought to mimic the adaptive durability of the slurry—the characteristic of shifting from malleable to strong depending on the force applied—in a solid conductive material.
Metals that conduct electricity are made bendable using conjugated polymers, described as “long, spaghetti-like molecules” by the ACS. However, flexible polymers often break if they’re hit repeatedly.
The goal for Wang’s team was to select the right combination of conjugated polymers to create a durable material that would act like the cornstarch particles in water.
After reaching this step, the team spread a thin layer of the mixture and dried it to make a film. Then, they were ready to test the material’s mechanical properties.
The material is not “constantly rigid” or “constantly flexible” but responds to body movement, explained Di Wu of the University of California
Image credits: American Chemical Society Meeting Newsroom
Instead of breaking apart from impact, the material deformed or stretched out. What’s more, scientists reported that the faster the impacts, the more stretchy and tough the film became.
The study highlights the applicability of the lightweight durable material outside of the lab. Examples of its use include smartwatch bands and wearable sensors as well as flexible electronics for health monitoring, such as cardiovascular sensors or continuous glucose monitors.
Additionally, Wang hopes the material will prove useful in 3D printing of personalized electronic prosthetics, allowing for devices that are flexible enough for human motion but sufficiently strong to resist accidental bumps.
“There are a number of potential applications, and we’re excited to see where this new, unconventional property will take us,” the investigator shared.
“Please tell me they called it ‘Chuck Norris,'” a reader joked
