The researchers used arrays of nine blowfly eyes coated with 250 nanometers of nickel. This initial template was then electroformed -- a method of electroplating -- to deposit nickel on the back to create a master template half a millimeter thick. The thickness of the master template can be thicker.
"Polymer replicas produced . . . by casting did faithfully reproduce features of a few micrometers and larger in dimensions," the researchers reported in the online edition of Bioinspiration & Biomimetics.
The master template can be used either as a die to stamp the pattern or as a mold. The intention is to use the master die/mold to produce not only daughter dies/molds, but to tile the templates so that they can imprint large areas. The researchers will probably expand their template to include 30 blowfly corneas.
"One of the nice things about a conformal coating like this is, it becomes nanograined," said Lakhtakia. "The surface of the die becomes very smooth so the polymer will probably not stick."
Many biological surfaces exist that could create manufacture surfaces for a variety of applications. The researchers are currently looking at butterfly wings to understand how the surfaces create colors without pigment.
"Interestingly, the emerald ash borer, an insect that has recently become a problem in Pennsylvania, mates by color," said Lakhtakia. "Would lures made from templates of the ash borer skin attract males?"
|Contact: A'ndrea Elyse Messer|