Celebrating advances in nanotechnology, researchers at Cornell University have etched on a silicon chip what is claimed to be the world's smallest, full-color American flag.
The chip features 15 monochrome images of the White House flanked by six full-color American flags, embedded with microscopic features reflecting the colors of the stars and stripes. There are three visible White House images and a dozen nanosized ones, 500 microns wide and 225 microns high, which appear as dots without magnification.
Six red, white, and blue flags on the chip measure 3 1.5 mm. When the chip is held at an angle, the colors are reflected by a pattern of lines etched into a thin layer of glass coating a silicon wafer. The lines are spaced at nanometer dimensions to diffract specific wavelengths of light. It is the light diffraction that produces the red, white, and blue.
If the flag were any smaller, its colors would disappear. Objects at the nanoscale are devoid of color because their dimensions are smaller than a wavelength of light.
"To put all this into perspective, three stars on a flag that fly over the nanobuilt White House would fit across the width of a red blood cell," says Cornell professor Carl Batt. The chip was made to honor the 21st Century Nanotechnology Research and Development Act, which authorizes four-year funding for nanotechnology research beginning in 2005.