Thinnest plates that can be picked up by hand created

University of Pennsylvania researchers, including one of Indian-origin, have created the thinnest plates that can be picked up and manipulated by hand, claims a study.

Despite being thousands of times thinner than a sheet of paper and hundreds of times thinner than household cling wrap or aluminum foil, the new corrugated plates of aluminum oxide spring back to their original shape after being bent and twisted.

Like cling wrap, comparably thin materials immediately curl up on themselves and get stuck in deformed shapes if they are not stretched on a frame or backed by another material.

Being able to stay in shape without additional support would allow this material, and others designed on its principles, to be used in aviation and other structural applications where low weight is at a premium, said the research team that included Prashant Purohit, an associate professor of mechanical engineering.

"Materials on the nanoscale are often much stronger than you would expect, but they can be hard to use on the macroscale," said lead researcher Igor Bargatin, assistant professor of mechanical engineering and applied mechanics.

"We have essentially created a freestanding plate that has nanoscale thickness but is big enough to be handled by hand. That has not been done before," Bargatin noted.

The researchers' plates are between 25 and 100 nanometres thick and are made of aluminum oxide, which is deposited one atomic layer at a time to achieve precise control of thickness and their distinctive honeycomb shape.

"The structures we make are no longer completely planar, instead, they have a three-dimensional shape that looks like a honeycomb, but they are flat and contiguous and completely freestanding," Bargatin said.

"It is like an egg carton, but on the nanoscale," Purohit pointed out.

The findings were published in the journal Nature Communications.