Researchers developed a reusable adhesive that activates in seconds underwater.
The new adhesive was developed by researchers at University of Illinois. This adhesive, which efficiently works underwater and is capable of holding weight up to 11 pounds is called as shape memory polymers (SMPs).
The research team proved that SMPs can retain dry adhesion properties when they are submerged. SMPs are classified as a smart material, as it is capable of manually transitioning between their original state and a deformed state. The research team were successful in adhering to the surfaces submerged in water as well as other liquid media such as oil by manipulating the state of their SMPs.
When pressure is applied to the submerged SMP in its original rubbery state, it is possible to squeeze out the liquid from the contact interface. Moreover, when there is sufficient pressure, SMPs transition to a glassy state, essentially creating a hermetic contact condition that maintains highly strong dry adhesion. However, the glassy state of SMP is not permanent. There are chances that the shape recovery properties of SMP will result in reversal of adhesion. Moreover, as it can easily switch between states, its adhesion is reusable.
It showed a maximum adhesion strength of 18 atm when submerged in freshwater condition and similar results were achieved for submersion in saltwater and oil. The research team conducted various experiments to find the applications of SMPs. Seok Kim, associate professor in mechanical science and engineering said, “These findings will result in reusable high-strength adhesive fasteners for wet or submerged wall mounting. The next step for this technology will be to further explore SMP adhesive systems to enable reversible adhesive grippers.”