Scientists at Nanyang Technological University, Singapore (NTU Singapore) have developed a reusable adhesive derived from shape-memory polymers that may one day enable robots, and maybe even humans, to cling to and subsequently climb walls.

According to the team of scientists, the reusable adhesive is more than 10 times stronger than the adhesive grip of a gecko’s foot and could eventually lead to the development of reusable superglue and grippers capable of holding heavy weights across both rough and smooth surfaces as well as to the development of climbing robots.
Source: NTU SingaporeSource: NTU Singapore

To accomplish this, the researchers reportedly maximized the adhesion of the smart adhesives by using shape-memory polymers that easily stick and detach when heat is applied to them. The researchers explained that the shape-memory polymers will return to their original shape once they have been deformed by the application of external stimuli — including heat, light or electrical current. Such properties, according to the researchers, make the polymers appropriate for use as switchable adhesives that can adapt to different surfaces.

In the lab, the team applied heat to E44 epoxy, which is a stiff and glass-like plastic at room temperature. However, once heat was applied to the material, it subsequently turned into a soft rubber-like material that can conform and adhere to microscopic nooks and crevices. Once the material cooled, it reportedly became glassy and thereby created an extremely strong adhesive bond thanks to a shape-locking effect.

Meanwhile, to detach the material from the surface, the researchers reheated the material, which reverted back to its rubbery state.

An article detailing the material, “Fibrillar adhesives with unprecedented adhesion strength, switchability and scalability,” appears in the journal National Science Review.

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