Robotic Lightning Bugs Emit Light for Motion Tracking and Communication

Researchers from MIT have designed a robotic firefly capable of flight and emits a glow that can be used for motion tracking and communication applications. The work builds on previous developments of a fabrication technique to build soft actuators, or artificial muscles, that flap the wings of tiny robots, allowing them to take flight. The robots themselves are so lightweight that they can’t carry sensors or other payloads, so the engineers have to track them via light using a trio of smartphone cameras in an indoor setting.

“If you think of large-scale robots, they can communicate using a lot of different tools — Bluetooth, wireless, all those sorts of things. But for a tiny, power-constrained robot, we are forced to think about new modes of communication. This is a major step toward flying these robots in outdoor environments where we don’t have a well-tuned, state-of-the-art motion tracking system,” said Kevin Chen, Assistant Professor at MIT’s Department of Electrical Engineering and Computer Science (EECS).

As mentioned earlier, the actuators were built on previous advancements in artificial muscles and are made by alternating ultrathin layers of elastomer and carbon nanotube electrodes in a stack and then rolling it into a cylinder. When a voltage is applied to that cylinder, the electrodes squeeze the elastomer, and the mechanical strain flaps the wing.

To get the actuators to glow, the team incorporated electroluminescent zinc sulfate particles into the top layer of the elastomer, which illuminate when subjected to a high-frequency electric field. Adjusting the chemical combination of the zinc particles can also change the color of the glow, such as green, orange and blue. The engineers are currently looking at ways to improve the robot’s illuminated actuators and the motion-tracking system to utilize the robots in outdoor settings and other large areas.