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A team of researchers, led by a �������ϲʿ����ӿ� Fellow, have created a 'super jelly' so strong it can be run over by a car and still hold its shape.

Oren Scherman, Professor of Supramolecular and Polymer Chemistry, led the Department of Chemistry team in the development of a jelly-like material that can hold up against the equivalent of an elephant standing on it, and completely recover to its original shape. 

The soft-yet-strong material, looks and feels like a squishy jelly, but acts like an ultra-hard, shatterproof glass when compressed, despite being 80 per cent water.

The non-water portion of the material is a network of polymers held together by reversible on/off interactions that control the material’s mechanical properties. This is the first time that such significant resistance to compression has been incorporated into a soft material.

The ‘super jelly’ could be used for a wide range of potential applications, including soft robotics, bioelectronics or even as a cartilage replacement for biomedical use. The results are reported in the journal Nature Materials.

The way materials behave – whether they’re soft or firm, brittle or strong – is dependent upon their molecular structure. Stretchy, rubber-like hydrogels have lots of interesting properties that make them a popular subject of research – such as their toughness and self-healing capabilities – but making hydrogels that can withstand being compressed without getting crushed is a challenge.

Working under the guidance of Professor Scherman, the team used barrel-shaped molecules called cucurbiturils to make a hydrogel that can withstand compression. The cucurbituril is the crosslinking molecule that holds two guest molecules in its cavity – like a molecular handcuff. The researchers designed guest molecules that prefer to stay inside the cavity for longer than normal, which keeps the polymer network tightly linked, allowing for it to withstand compression.

“At 80% water content, you’d think it would burst apart like a water balloon, but it doesn’t: it stays intact and withstands huge compressive forces,” said Scherman, who is also Director of the University’s Melville Laboratory for Polymer Synthesis. “The properties of the hydrogel are seemingly at odds with each other.

“People have spent years making rubber-like hydrogels, but that’s just half of the picture,” said Scherman. “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.”

Dr Zehuan Huan, first author of the study added:  “To the best of our knowledge, this is the first time that glass-like hydrogels have been made. We’re not just writing something new into the textbooks, which is really exciting, but we’re opening a new chapter in the area of high-performance soft materials,” 

Researchers from the Scherman lab are currently working to further develop these glass-like materials towards biomedical and bioelectronic applications in collaboration with experts from engineering and materials science.

The research was funded in part by the Leverhulme Trust and a Marie Skłodowska-Curie Fellowship.

This piece is  first published on the University of Cambridge's website.