Scientists have developed a whole new material that is soft but tough that can return to its original shape after being run over by a car or, to use a more natural example, after being walked over by an elephant.
Composed of 80% water, the parts of the material that are not water allow it to act like ultra-hard glass when compressed.
Researchers believe this is the first time that a soft material like this has exhibited excellent resistance to compression.
And after further development, “super jelly” could have a whole host of practical applications, according to the team behind the material, everything from use in soft robotics to improving the flexibility of cartilage replacement used in the human body.
“80% of the water content, you would think it would burst like a balloon, but it is not the case: it remains intact and resists huge compressive forces,” the chemist Oren Scherman from the University of Cambridge in the UK said.
The properties of the hydrogel are apparently at odds with each other.
Elastic hydrogels have many characteristics that make them interesting to materials scientists, but they are generally crushed when compressed.
The reason this “super jelly” is different because of its molecular structure and the way it uses cross-links: two molecules linked by a chemical bond.
Here, barrel-shaped molecules called cucurbiturils acted as crosslinks, each containing two guest molecules in its cavity like a molecular handcuff.
In doing so, these guest molecules stay in place longer than usual.
This means that the network of polymers that control the mechanical properties of the material are more closely linked and better able to withstand compression.
Overall, researchers describe it as a “slowing down” of the material’s dynamics, so its performance can range from rubber-like states to glass-like states.
“The way the hydrogel can withstand compression was amazing, it wasn’t like what we’ve seen in hydrogels,” says University of Cambridge chemist Jade McCune.
“We also found that compressive strength can be easily controlled by simply changing the chemical structure of the guest molecule inside the handcuff.
While other hydrogels are known for their strength and self-healing, taking the weight of a 1,200 kg (2,646 lb) car like in the video above is not something they have. could have done before.
“As far as we know, this is the first time that glass-like hydrogels have been produced. We’re not just writing something new in the textbooks, which is really exciting, but we’re opening a new chapter in the field of high-performance soft materials,” says Zehuan Huang, chemist at the University of Cambridge and lead author of the study.
One manner wherein this material is probably used is as a hydrogel pressure sensor for the real-time tracking of moves inclusive of standing, walking, and jumping.
It might be capable of deform and take measurements earlier than returning to its original shape.
Further development is needed before the material is ready for biomedical and bioelectronic purposes.
However, this first demonstration holds great promise, as do many other recent developments in hydrogel science.
“People have spent years making rubber-like hydrogels, however that is simply half of the picture,” says Scherman.
“We’ve revisited traditional polymer physics and created a brand new class of materials that span the entire variety of material properties from rubber-like to glass-like, finishing the whole picture.”
This research has been published in Nature Materials.