They will perform a useful function
Engineers at the Massachusetts Institute of Technology have developed insect-sized robots equipped with tiny artificial muscles. They allow them to flap their wings.
Researchers have also found a way to embed tiny electroluminescent particles into these artificial muscles so they can emit light as they fly. Thus, robots can use this light to communicate with each other and even signal for help in emergencies.
For example, if a robot goes on a search and rescue mission to a collapsed building and finds survivors there, it can use light to signal others about it.
Previously, researchers have demonstrated the work of artificial muscles for insect robots. They stacked alternating layers of elastomer and carbon nanotubes and then rolled the stack into a soft cylinder. When voltage is applied to the cylinder, the electrodes compress the elastomer and the mechanical stress causes the robot to flap its wings.