With space and weight restrictions, what would you take if you went to Mars? An ideal option could be a unique material that can transform shapes into any object you imagine.
In the morning, you could shape this material into eating utensils. Once breakfast is over, you can turn your fork and knife into a shovel to tend your Martian garden. And then, when it’s happy hour on the red planet, this pike could become a mug for your Martian beer.
What sounds like science fiction may be a step closer to reality. Researchers at the University of Chicago’s Pritzker School of Molecular Engineering have created a new type of plastic whose properties can be hardened by heat and then locked in by rapid cooling, a process known as quenching. Unlike conventional plastics, the material retains this rigidity once returned to room temperature.
The results, published in the journal Science on Thursday, could one day change the way astronauts prepare for space.
“Rather than taking all the different plastics with you, you take this one with you and then give it the properties that you need,” said Stuart Rowan, a chemist at the University of Chicago and author of the new study. .
But space isn’t the only place the hardware could be useful. Dr. Rowan’s team also sees its potential in other environments where resources are scarce, such as at sea or on the battlefield. It could also be used to make soft robots and improve plastic recycling.
“We all rely on plastic in our daily lives,” said Shrayesh Patel, a chemical engineer at the University of Chicago and author of the new study. But foam cups, trash bags and spectacle lenses, for example, all require plastics with different properties.
In contrast, a single material that can be shaped to different needs “simplifies the manufacturing of plastics,” Dr. Patel said. It would also make plastic more sustainable, as items could all be processed together when recycling. This plastic must be sorted while recycling only helps ensure that a small fraction is reused, he explained.
Modern plastics are made of permanently linked chains of molecules, making them difficult to break down. But the Chicago researchers say their new material is “pluripotent” – a term generally used to describe the generic property of stem cells – or made of bonds that can be broken and reformed using heat.
They were inspired by the way blacksmiths temper, or gradually heat and then quickly cool, steel in a furnace. But unlike metal, plastics are lightweight and can be molded at temperatures achievable with an oven or stove.
The researchers heated the reddish, translucent plastic to temperatures between 140 and 230 degrees Fahrenheit, then stored it in a freezer to cool quickly. When tempered at lower temperatures, more molecular bonds form, making the plastic stiffer. But at higher temperatures, the material becomes softer and stickier.
The team molded the plastic into a spoon stiff enough to scoop the peanut butter into a jar and a fork to scoop up the cheese. They also made an adhesive strong enough to stick two pieces of glass together, as well as a small claw similar to one you might find in a toy machine.
Julia Kalow, a chemist at Northwestern University who was not involved in the study but wrote a perspective on the results for science, came up with the idea of a single material capable of achieving a variety of unique and exciting properties. “Now that we know it could be useful to achieve this property, many other researchers will be inspired to find new ways to achieve this goal,” she said.
There are limits to the first generation of pluripotent plastic. Although the team showed that the material can be reprocessed at least seven times and maintain its shape for at least a month, its shelf life remains uncertain.
“They won’t replace commodity plastics yet,” said Nicholas Boynton, a University of Chicago graduate student who led the study’s experiments. The material cannot yet achieve the strength of a plastic bag, for example, nor the elasticity of a rubber band.
“We’re not quite there yet, but we’re pretty close,” Mr. Boynton said. “I think having a material that can access this huge range is what’s really exciting at this point.”