Have you ever spilt water on a piece of tape and noticed it loses its stickiness? Water and adhesives usually don’t mix, but researchers from Nanyang Technological University in Singapore have created a new type of glue that works in wet environments because it only hardens when a voltage is applied.
Nicknamed Voltaglue because apparently all the cool glue names were already taken, the new adhesive has been in development for over a year by a team of scientists at NTU’s School of Materials Science and Engineering, led by Assistant Professor Terry Steele.
Most super-strong adhesives, like superglue, harden when they come into contact with moisture in the air, when exposed to high heat, or when mixed with other chemicals. But to make a glue that wasn’t affected by the environment around it, like the presence of water, the scientists engineered it to only harden when a voltage was applied.
To realize this special electrocuring behaviour, the Voltaglue was developed using hydrogels made from carbon molecules called carbenes that are attached to branch-like pieces of plastic called dendrimers. When electricity is introduced, the carbenes react and ‘hook’ onto nearby surfaces. The longer a voltage is applied, the stronger the bond that’s created.
So besides being usable under water, the new adhesive can also be custom cured to varying levels of hardness. When fixing a hole in a boat, a long application of electricity means the Voltaglue will be extra hard and stick for a very long time. But for medical applications, less voltage could be used, resulting in a softer glue that flexes to accommodate a patient’s movements.
But here’s the coolest part: Steele and his team are not only working to make their new adhesive cure in just a few seconds, but also a way to undo the hardening process. With reversible glue, everything from cars to smartphones could be easier to build–and even easier to break apart and repair at the end of their life.