One way that scientists control the structure of materials at the nanoscale – where features are a few to several hundred nanometers (nm) – is by using “self-assembly,” in which molecules are designed such that they spontaneously come together to form a desired structure or pattern. Self-assembly is a powerful approach to controlling order at the nanoscale and is one way that scientists can design certain properties into a material for specific applications, such as solar energy conversion and storage.