Features: Feb. 25, 2002

Nanomaterials Take on New Shapes

A Rensselaer researcher has provided new insights on how to manufacture original complex 3-D nanostructures on a massive scale for faster computers and highly sensitive environmental and biological sensors.

Yiping Zhao, research assistant professor of physics at Rensselaer, is the first to use a simple technique to grow nanosquare springs and other new 3-D structures that can be placed anywhere on a chip.

The technique also is a "one-size-fits all" approach in making photonic crystals, materials that transmit signals with light rather than electrons. Photonic crystals could make it possible to build computers much faster than today's. Researchers must use several methods to make the crystals that Zhao can do in one step.

Zhao's research has been accepted for publication in the International Journal of Nanoscience. Other original structures Zhao has formed include triangles, pentagrams, spring-like structures, and even "nanoflowers."

Zhao's patent-pending method is based on Glancing Angle Deposition (GLAD), used for thin-film vapor deposition. The technique involves melting into a liquid a material, such as copper, which is then evaporated into a vacuum. The vapor is then directed at an 85-degree angle toward the substrate that sits about 12 inches away.

The substrate is then rotated or tilted and sped up or slowed down by computer programming as the material is being deposited on the surface to engineer the desired shape.

"We are the first to make many specific shapes of nanostructures, and the first to use the method as a nanolithography tool, which can grow a single nanostructure on any desired position of a chip," Zhao said.