Researchers at the University of California, Berkeley, developed a simple technique that turns genetically-engineered viruses into "useful tools," says Technology Review's Prachi Patel. The researchers made the viruses "arrange themselves into extremely ordered patterns with distinctive properties, such as color or strength," Patel says — an ability that could eventually allow researchers to turn the viruses into optical devices or biological scaffolds on which tissues or bones needed for transplant could be grown. The researchers say that viruses can be useful as building blocks as many different materials can be attached to their surfaces. "What's even more important about the new work," Patel adds, "is the precise control over viral self-assembly, resulting in large-scale structures with multiple levels of organization."