Scientists at the University of Cambridge have developed a new type of soft material capable of withstanding tremendous forces. Described as a ‘superjelly’, this novel hydrogel uses a unique type of internal structure known as molecular cuffs to respond to compression by transitioning to a glass-like state, giving it a can be passed by a car without being crushed.
Hydrogels have long been of interest to materials scientists. Their high water content makes them suitable for use in the human body, while also giving them stretchy and self-healing properties that can be used in robotics, contact lens technology, tissues artificial and wound healing. And the authors of this new study sought to expand these possibilities, by tweaking the molecular structure beneath the material.
“To create materials with the desired mechanical properties, we use crosslinking, where two molecules are joined together via a chemical bond.” Dr. Zehuan Huang, first author of the study said. “We use reversible crosslinkers to make a soft and stretchy hydrogel, but making a rigid and compressible hydrogel is difficult and designing a material with these properties is a challenge.” quite the opposite of intuitive.”
To this end, the scientists turned to barrel-shaped molecules called cucurbiturils, which have the ability to “cuff” other pairs of molecules together inside its cavity. They then used molecules specifically designed to stay inside the cavity longer than usual, keeping the network tight and allowing it to change from a rubber-like state to a rubber-like state. Ultra-hard, shatter-resistant glass-like state.
According to the team, this helps the “super jelly” be able to withstand the same force as an elephant standing on it without being crushed. And since there was no elephant in hand, the team put the material to the test by running a car over it, to demonstrate it could return to its original shape.
Testing the durability of “Super Jelly”
“With 80 percent water, you’d think it would burst like a water balloon. But it’s not: It’s intact and can withstand tremendous compression,” he said. Professor Oren A. Scherman, who led the study, said. “The properties of the hydrogel seem to be contradictory.”
The scientists also used the new material to make a pressure sensor for human movements, such as standing, walking and jumping. They are continuing to develop the material with the aim of adapting it to biomedical applications, such as cartilage replacement and soft robotics.
Dr. Huang says: “To our knowledge, this is the first time that a glass-like hydrogel has been created. This is a new chapter in the field of high-performance soft materials.”
The study was published in the journal Nature Materials.
Refer to New Atlas