A Collection of Articles
Katherine Bourzac

A View from Katherine Bourzac

First 3-D Patterned Nanostructures

Patterned tin and nickel panels self-assemble into nanoboxes.

  • August 20, 2009

Chemists have become very skilled at building 2-D nanostructures, but making 3-D patterned structures for drug delivery, electronics and other applications has proved more challenging. In particular, no one has been able to make 3-D structures with patterned surfaces.

Varying etching conditions influences the angles formed by the
panels in these nanoboxes. The left column is a close-up of the
tin hinge material. The other columns show the boxes at
different magnifications. The panels are patterned with the letters
“JHU” with line-widths of 15 nanometers. Credit: ACS/Nano Letters

David Gracias and Jeong-Hyun Cho of Johns Hopkins University in Baltimore have overcome this problem. They first made arrays of patterned, cross-shaped nickel structures on a silicon wafer, then added tin hinges. When placed in a plasma etching chamber, the flat structures folded up into cubes and released from the wafer. To make nanocubes as small as 100 nanometers a side, the researchers added another panel.

The work is described online in the journal Nano Letters, where the researchers write that it should apply to other polyhedral shapes as well.

You've read of free articles this month.