In a groundbreaking discovery, Japanese scientists have unveiled a remarkable adhesive that defies convention by behaving like a switch – adhering and detaching on demand.
Designing adhesives has always been a delicate balancing act between two conflicting properties – strong adhesion and easy detachment. However, researchers at Japan’s National Institute for Materials Science (NIMS) have succeeded in developing an adhesive that perfectly blends both characteristics. The secret lies in the vital ingredient, caffeic acid, which can form and break cross-links under different light wavelengths.
The scientists created a polymer infused with caffeic acid and applied it to a surface. When exposed to 365-nanometer UV light, the adhesive solidified into a robust film with impressive room-temperature shear adhesion strength of up to 7.2 MPa. Once the adhesion is no longer necessary, simple exposure to 254-nanometer UV light undoes the cross-links, restoring the adhesive to its original state. This process leaves no residue, and the glue regains its complete properties, making it reusable.
The adhesive underwent rigorous testing, including repetitive bending and lifting a 40-kg weight, which it sustained for an impressive 72 hours without showing signs of failure. In further tests, the scientists used the adhesive to repair cracked silicon tubes and subjected them to high-pressure water flow, finding no leaks – a testament to its durability.
The versatility of this adhesive extends even underwater, thanks to embedded magnetic nanoparticles. When a magnetic field is applied, the nanoparticles heat up, fusing the bond to the substrate, further broadening its potential applications.
This remarkable material has the potential to revolutionize various industries, offering products that can be effortlessly dismantled into components at the end of their lifecycle, which can then be transformed into new products. From reducing waste to enhancing recycling processes, this adhesive could usher in a new era of sustainability and efficiency.
The research, demonstrating the adhesive’s groundbreaking capabilities, was published in the journal Advanced Functional Materials. With such promising advancements, this glue may soon become a game-changer, paving the way for a more sustainable and resource-efficient future.
Source: NIMS