Combining opposing properties in one material is very difficult. If something is soft and squishy it is hard to expect it to be durable. However, scientists at the University of Cambridge have developed a jelly-like material, which is super soft and squishy, but can easily withstand the weight of an elephant or a car. It becomes even more impressive after you find out that it is 80 % water.
Imagine a material, which acts like a jelly, is full of water, but doesn’t burst like a bubble even under extreme pressure. This is not some kind of a science fiction story – it is a hydrogel developed at the University of Cambridge. This impressive material is mostly water, but doesn’t begin to leak even after a car is driven over it repeatedly. Scientists say that an elephant could stand on it with no issues whatsoever. And this is all thanks to its network of polymers that act like molecular handcuffs.
Inside of this hydrogel there are cucurbiturils – barrel-shaped molecules, which crosslink and hold two guest molecules inside of each of them. Scientists created guest molecules that prefer to stay inside the cavity for longer than normal, which resulted in this highly resistant material, which is still very soft. In fact, it is not that jelly-like under the wheel of a car – it becomes hard as glass under that kind of pressure, because when weight is applied those molecular handcuffs tighten up significantly.
Professor Oren A Scherman, lead author of the study, said: “People have spent years making rubber-like hydrogels, but that’s just half of the picture. We’ve revisited traditional polymer physics and created a new class of materials that span the whole range of material properties from rubber-like to glass-like, completing the full picture.”
And the idea that this super-jelly material could withstand the weight of an elephant or a car isn’t just some brave hypothesis – scientists actually drove a car on top of it over and over again:
It is interesting to see that the material, which is 80 % water, didn’t become a puddle after this kind of a test. Furthermore, because scientists used reversible crosslinkers to make soft and stretchy hydrogels, the material was soft again after the car drove away.
But what can scientists do with a material like that? Well, they are thinking about soft robots, bioelectronics or even medical applications. For example, a similar hydrogel could be used in cartilage replacements. In many applications these soft hydrogels could make installation easier while still being very strong.
Source: University of Cambridge