The article reports on the development of colloidal "atoms" that can be self-assemble into a variety of controlled structures, including chiral clusters. The researchers have synthesized magnetic colloids that contained an oil-based ferrofluid and micrometer-sized silica particles. They discovered that when the dimers had different-sized silica particles, the chain was forced to coil, and if the size ratio between the particles was high enough, a single helicity developed.