Glue hardens when voltage applied and works in wet

Adhesive could be used for underwater ship and pipe repairs, and replace sutures in surgery

Engineers from Nanyang Technological University in Singapore have invented a glue that will harden when a voltage is applied to it and retain its adhesive properties when wet.

The adhesive, nicknamed Voltaglue, could be used for commercial applications such as underwater ship and pipe repairs, and replacing sutures in surgery. Tailoring the properties of the adhesive to be more “gel-like or rubber-like” would “work well in vibrating or damp environments,” said the team.

Assistant professor Terry Steele, leading the research project, said that most glues in the market don’t work under wet conditions – they may harden upon contact with moisture in the air. Others, like epoxy, often used in electronic mobile devices, have to be baked to 150°C, or made using two different chemicals mixed together. Steele said: “We had to find a way to make glue which cures (hardens) when we want it to without being affected by the environmental conditions, so electricity was the best approach.” 

Voltaglue is developed using hydrogels consisting of carbon molecules called carbenes grafted on to plastic molecules known as dendrimers. Upon contact with electricity, the carbenes, which can hook on to any surface nearby, are released. The amount of “hooks” created depends on how long electricity is applied and how many carbenes are present. This means that the hardness and strength of the glue can be adjusted by the amount of time voltage is applied to it.