As amazing as it is that we can create objects at the micro- and nanoscale, the more amazing feat is to build something out of these objects, which is a very difficult task. The building blocks are so small that there are no effective tools for creating large scale objects in quickly, so researchers try to find ways for the blocks to self-assemble into more complex structures. Researchers at the University of California, San Diego have found a way to control the spontaneous alignment of silver nanocubes, which could lead to advances in optics and plasmonics.
These silver nanocubes, which are roughly 100 nm to a size, will already assemble on their own into long chains that look like rows in Tetris, with their faces touching. The researchers decided to see if they could cause the silver to attach differently by adhering polymer strands to them. With short polymer strands, the cubes aligned just as they would without the polymer there. With long strands however, the cubes connected corner-to-corner. This difference may not seem too great, but the films the researchers made from these different chains responded to different wavelengths of light.
The hope for this discovery is that it will be used to create nano-antennas and nano-lenses. Even though the cubes are much smaller than the wavelength of light, it is still possible for them to interact with visible photons, thanks to plasmonic effects. If these lenses and antennas are ever made they could be used in optical circuitry and as a means to have light directly interact with molecules.