'Nanobamas' Crafted

President-elect Barack Obama's face seems to be everywhere these days, on 24-hour news channels, the Internet, and on T-shirts, mugs and other items commemorating the historic election of Nov. 4. A University of Michigan professor has even created 3-D portraits of the soon-to-be 44th president that are smaller than a grain of salt and dubbed them "nanobamas."

John Hart, an assistant professor in the department of mechanical engineering, made the mini-Barack Obama likenesses with his colleagues to raise awareness of nanotechnology and science.

Through an electron microscope, it's possible to see these .5-mm images of Barack Obama. Each is made of around 150 million carbon nanotubes, representing the number of Americans who voted in the 2008 presidential election. (Photo: A. John Hart)

Each one contains about 150 million carbon nanotubes stacked vertically like trees in a forest. A carbon nanotube is an extraordinarily strong hollow cylinder about 1/50,000th the width of a human hair.

"Developments like this are an excellent way to bring the concepts of nanotechnology to a broader audience," said Hart, who made the portraits with his colleagues by working late on a Friday evening. "Also, we thought it would be fun."

Carbon nanotubes could be used in solar cells and batteries, new methods of diagnosing and treating disease, next-generation computer processors and memory, and stronger lightweight materials. Hart's Mechanosynthesis Group focuses on studying how to make nanostructures like nanotubes, and how to use these small-scale building blocks in electronics, energy devices and high-performance materials.

A step-by-step diagram showing how the nanobamas are created. (1) convert an image (original by Shepard Fairey) of Barack Obama to a line drawing; (2) shrink the drawing and print it onto a glass plate (mask), using a laser system; (3) shine ultraviolet light through the mask, and onto a thin layer of polymer on a silicon wafer, thereby patterning the polymer by photolithography; (4) coat the wafer with a thin layer of catalyst nanoparticle "seeds" for nanotube growth; (5) remove the remaining polymer, leaving the catalyst seeds in the shapes of the nanobamas; (6) grow the CNTs from the catalyst patterns, by placing the wafer in a high-temperature furnace and filling the furnace with a carbon-containing gas; (7) take pictures of the structures, which are barely visible to the naked eye, using electron and optical microscopes. (Structures and images made by John Hart, Sameh Tawfick, Michael De Volder, and Will Walker)

To create the nanobamas, the researchers converted Shepard Fairey's famous red, white and blue poster of Barack Obama to a line drawing. They shrunk it and printed it on a glass plate with a laser to create a mask. They shined ultraviolet light through the masked glass plate on to a silicon wafer to create the pattern. Then they grew the carbon nanotubes on the pattern, using a high-temperature chemical reaction.

The researchers photographed the nanobamas with an electron microscope. The faces are half a millimeter in size.

Nanobama is Hart's latest artwork too small for the naked eye to see. His complete gallery is at nanobliss.com, a site he started in 2006, inspired by the beauty in the structures he was building for his dissertation. Hart has used this technique to make Michigan logos, snowflakes and a mock Absolut Nano ad that shows nanotubes grown in the shape of a vodka bottle.

For more information, visit: www.engin.umich.edu