Nanoparticles that self-assemble into complex optical structures sounds like an early ingredient in a future Robot Uprising recipe, but the science team at University of California, Berkeley thinks they’ll be useful for nicely tame things. The self-assembly of the nanoparticle silver crystals can be controlled to produce different nano “devices” and it’s a a neat way of putting together nanotech that is more typically produced top-down by lithography. The devices can be as diverse as colour-changing paint, optical computer elements, and ultrasensitive chemical sensors.