View Larger Version | When properly guided, nanoparticles can arrange themselves into a variety of ordered structures (images shown areas nanometers across). Gray images are transmission electron microscope views of nanoparticles steered into ordered structures similar to those naturally achieved by gemstones (illustrated as insets). Brown and orange images shown other variations that self-assembly can achieve. One technique uses DNA strands to guide nanoparticles into a cubic structure, revealed by the way X-rays scatter from the array (bottom right). Credit: Top three: Courtesy of Chen Wei/National Univ. of Singapore; Middle, from left: E. Shevchenko; Chen Wei; E. Shevchenko; Bottom, from left: Chen Wei; E. Shevchenko; O. Gang