The researchers' plates are strong enough to be picked up by hand and retain
their shape after being bent and squeezed.
(December 5, 2015) Scientists and engineers are engaged in a global race to make new materials that are as thin, light and strong as possible. These properties can be achieved by designing materials at the atomic level, but they are only useful if they can leave the carefully controlled conditions of a lab.
Researchers at the University of Pennsylvania have now created the thinnest plates that can be picked up and manipulated by hand.
Despite being thousands of times thinner than a sheet of paper and hundreds of times thinner than household cling wrap or aluminum foil, their 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.
The hexagonal corrugation of the plates is responsible
for their stiffness and strength.
The study was led by Igor Bargatin, the Class of 1965 Term Assistant Professor of Mechanical Engineering and Applied Mechanics in Penn’s School of Engineering and Applied Science, along with lab member Keivan Davami, a postdoctoral scholar, and Prashant Purohit, an associate professor of mechanical engineering. Bargatin lab members John Cortes and Chen Lin, both graduate students; Lin Zhao, a former student in Engineering’s nanotechnology master’s program; and Eric Lu and Drew Lilley, undergraduate students in the Vagelos Integrated Program in Energy Research, also contributed to the research.
They published their findings in the journal Nature Communications.
“Materials on the nanoscale are often much stronger than you’d expect, but they can be hard to use on the macroscale” Bargatin said. “We’ve essentially created a freestanding plate that has nanoscale thickness but is big enough to be handled by hand. That hasn’t been done before.”