Chad Mirkin, a Northwestern University professor of chemistry, medicine, materials science and engineering, and colleagues printed the logos, as well as an integrated gold circuit, using a new printing technique called Polymer Pen Lithography that can write on nanometer, micrometer and millimeter length scales using only one device.

"We consider Dip-Pen Nanolithography, which is nanotechnology's version of the quill pen, and now Polymer Pen Lithography, to be two of Northwestern's most important inventions," said Mirkin, who created both technologies.

In the case of the Olympic logo, the researchers started with a bitmap image of the logo and uniformly printed 15,000 replicas onto a gold substrate using an "ink" just one molecule thick. The process took less than 40 minutes. The logo is so small that 2,500 of them would fit on a single grain of rice.

The study that included Fengwei Ho, Zijian Zheng, Gengfeng Zheng, Louise Giam and Hua Zhang appears in the online journal Science Express.