Researchers create Harry Potter's 'invisibility cloak' - for nanoparticles

Washington, Mar 7 : Harry Potter's 'invisibility cloak' has become a reality thanks to Carnegie Mellon University researchers Michael Bockstaller and Krzysztof Matyjaszewski - at least for nanoparticles.

The researchers, along with colleagues from the departments of Materials Science and Engineering and Chemistry, found a way to control the structure of nanoparticles, thereby 'shrinking' their visible size by a factor of factor of thousands without affecting their actual physical dimension.

The boffins say that the new "particle invisibility cloak" will help create a vast array of new material technologies that combine unknown property combinations such as strength and durability with optical transparency.

Michael Bockstaller, an assistant professor of materials science and engineering, said that the new technique would provide a solution to many problems associated with the application of nanomaterials.

"What we are doing is creating a novel technique to control the architecture of nanoparticles that will remedy many of the problems associated with the application of nanomaterials that are so essential to business sectors such as the aerospace and cosmetics industry," he said.

In current material technologies, colloidal particles are omnipresent as additives in order to enhance strength and wear resistance and other attributes.

Light scattering that is associated with the presence of particles often results in an undesirable whitish, or milky, appearance of nanoparticles.

By grafting polymers onto the particles' surface, the researchers successfully created a way to prevent this problem.

"Essentially, what we learned how to do was to control the density, composition and size of polymers attached to inorganic materials which in turn improves the optical transparency of polymer composites. In a sense, light can flow freely through the particle by putting 'grease' onto its surface," said Matyjaszewski, the J.C. Warner University Professor of Natural Sciences in the Department of Chemistry.

The study appears in the recent edition of Advanced Materials Magazine.

ANI