Now, glue that can switch on and off

British scientists have created a special type of glue that can be switched on and off.

London, Aug. 13 : British scientists have created a special type of glue that can be switched on and off.

The scientists say that the material loses and regains its stickiness with the alterations in the acidity around it.

The new glue is made of polyelectrolytes, molecular chains that are electrically charged and change shape in response to the environment.

According to researchers, a polyelectrolyte can stretch out at one acidity level, and roll into a ball at another.

Investigators at the University of Sheffield have demonstrated that materials coated with oppositely-charged polyelectrolytes stick tightly when brought together in water. They, however, came apart when immersed in water above a certain acidity level.

The bonded material could be re-stuck together simply by re-immersion in lower acidity water.

"There are several advantages to the mechanism. It's strong but reversible in that it can be turned off and still be reused," the Scotsman quoted team leader Dr Mark Geoghegan as saying.

The researchers believe that their discovery can have important medical application, wherein the body's natural acidity will act as a trigger for releasing drugs.

"Trying to identify where this will be used... is difficult. As scientists, we have contributed what you might call the molecular tools of nanotechnology with our adhesive, but it is up to engineers to decide how to use it," said Dr Geoghegan.

"Drug delivery is always a possibility because different parts of the body have different pH values. A possibility is that the body's natural pH could be used with the adhesive to allow drug release," he added.

ANI