THURSDAY, 3 MARCH 2022
What is 80% water, but ultra-hard and shatterproof? A new material developed by a team at the University of Cambridge is all those things, and it may have applications in biomedical and bioelectronic technologies. The material is a hydrogel, which means it can swell and retain water while maintaining its integrity due to the cross-linking bonds between the network of polymers that make up the gel. ‘We use reversible cross-linkers to make soft and stretchy hydrogels, but making a hard and compressible hydrogel is difficult, and designing a material with these properties is completely counterintuitive’, said the study’s first author, Dr Zehuan Huang. The team managed nevertheless, using barrel-shaped molecules called cucurbiturils to cross-link suitable guest molecules. These barrel-shaped molecules help keep the polymer network tightly linked even when expanded, allowing it to withstand compressive forces. Altering the property of the guest molecules in this way can affect the strength of the material.
‘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’, said Huang. The researchers have used the material to create hydrogel pressure sensors for human movements, but no doubt there are many further applications of this super jelly.