(July 2, 2015) Using
molds to shape things is as old as humanity. In the Bronze Age, the copper-tin
alloy was melted and cast into weapons in ceramic molds. Today, injection and
extrusion molding shape hot liquids into everything from car parts to toys.
For this to work, the mold needs to be stable while the hot
liquid material hardens into shape. In a breakthrough for nanoscience, Cornell
polymer engineers have made such a mold for nanostructures that can shape
liquid silicon out of an organic polymer material. This paves the way for
perfect, 3-D, single crystal nanostructures.
The advance is from the lab of Uli Wiesner, the Spencer T.
Olin Professor of Engineering in the Department of Materials Science and
Engineering, whose lab previously has led the creation of novel materials made
of organic polymers. With the right chemistry, organic polymers self-assemble,
and the researchers used this special ability of polymers to make a mold dotted
with precisely shaped and sized nano-pores.