Latest on twitter:
Scientists at UC San Diego have made a bioluminescent bacterial billboard. They call it a “living neon sign composed of millions of bacterial cells that periodically fluoresce in unison like blinking light bulbs.” Making it all work “involved attaching a fluorescent protein to the biological clocks of the bacteria, synchronizing the clocks of the thousands of bacteria within a colony, then synchronizing thousands of the blinking bacterial colonies to glow on and off in unison.”
These are referred to as biopixels.