With a niggling bit of assistant from our slimy , shelled friends , the humble snail , scientists have developed a wickedly sticky superglue that ’s strong enough to hold a human being from a ceiling with just a stamp - sized patch . Best of all , justlike a geckocreeping across a paries , it ’s two-sided and can be switched on or off as demand .
Reporting in the journalProceedings of the National Academy of Sciences , scientist at the University of Pennsylvania set out to grow a superstrong but reversible adhesive agent . For inspiration , they looked no further than the natural human race .
shellfish , most notably snails and slugs , are capable of sticking to surfaces thanks to a gloopy mucus they raise . In its wet contour , this allows for just the right level of stickiness while also allowing the animate being to move . However , once hardened , the mollusk can impound itself to a surface for farseeing stop of time .
While on the hunt for stuff like this , a member of the inquiry squad came across a hydrogel made of a polymer called polyhydroxyethylmethacrylate , cognise as PHEMA for short , that was rubberlike when pixilated but unbending when dry . In this case , its reversibility is controlled by urine .
Further investigation into PHEMA cement its place as an ideal candidate . If applied to a open in its wet body politic , it continues to spread into the bantam fling and cavities , unlike other sticky materials that be given to shrink as they dry out , which bequeath them prone to peeling away .
" It ’s like those puerility toy that you throw on the bulwark and they stick to . That ’s because they ’re very flabby . Imagine a plastic flat solid on a paries ; it make out off easily . But squishy things will adjust to the cavities , " go author Shu Yang , a prof in the Department of Materials Science and Engineering and in the Department of Chemical and Biomolecular Engineering , said in astatement .
“ When materials dry out , they usually shrink . If it cringe from the surface , it no longer require to conform to the microcavities and it ’ll belt down out , " said Yang . " Our PHEMA adhesive material does n’t come out out . It stays conformal . It remember the embodiment even when it ’s ironic and rigid . "
evidently , you would n’t want to construct a house or a physique a automobile with this stuff , as the rainfall will make poor body of work of its stickiness . However , the researchers say an adhesive material with a water system - trigger two-sided could have some useful app program inscientific inquiry and medicine .
Meanwhile , scientists are also on the hunt club for other adhesives that could become two-sided by responding to cues , whether that be chemical substance and pH or light and heat .
