Scientists find electrifying solution to a sticky problem
25 August 2015
Scientists from Nanyang Technological University, Singapore (NTU Singapore) have developed an adhesive that hardens when a voltage is applied to it.
The new adhesive, dubbed 'Voltaglue', opens up a host of possible practical applications, from making underwater repair works for ships and pipes, to being a versatile tool for doctors performing surgery.
Assistant Professor Terry Steele, the lead scientist on this research project from NTU’s School of Materials Science and Engineering, said it took them over a year to develop an adhesive that could work in wet conditions.
“Most glues in the market don’t work under wet conditions, much like how sticky tapes won’t work if the surface is wet, since the adhesive will stick to the water instead of the surface,” says the American scientist, who graduated from the University of Minnesota before he moved to NTU Singapore.
Usually adhesives such as superglue harden upon contact with moisture in the air. Others like epoxy, have to be 'baked' at high temperatures or made using two different chemicals mixed together. These methods are unsuitable in wet environments.
Steele's team has called their new process 'electrocuring', and it can be customised for different applications.
“For example, if we are gluing metal panels underwater, we want it hard enough to stick for a long time. However, for medical applications, we want the glue to be more rubber-like so it wouldn’t cause any damage to the surrounding soft tissues,” says Steele.
Voltaglue comprises hydrogels consisting of carbon molecules called carbenes grafted onto tree-shaped polymer structures called dendrimers.
Upon contact with electricity, the reactive carbenes, which are capable of hooking onto any surface nearby, are released. The amount of 'hooks' created depends on how long electricity is applied and how many carbenes are present.
Another useful feature of Voltaglue is that it can be made reversible. Adhesives that can be cured and subsequently 'un-cured' would enable manufacturers to assemble and dissemble parts with ease, minimising the need for bolts, nuts and screws.
Steele and his team are now working to improve their new electrocuring glue so it can harden in just a few seconds, compared to around 30 seconds at present.