Robotic fireflies light up with every flap of their wings
Engineers at MIT have added a new ability to existing flying robots – they can now glow when they flap their wings. Inspired by fireflies, this fluorescence could help with communication or tracking of the tiny, lightweight robots.
The new work builds on the team’s previous developments with ultra-light flying robots that are fairly durable for their scale. The key ingredient of earlier work was a soft actuator, which consists of a thin cylinder made of alternating layers of elastomer and carbon nanotubes. When a voltage is applied, the carbon electrodes squeeze the elastomer, which produces a mechanical strain that flaps the wing.
For the new study, the researchers modified these actuators so that they also light up when they’re working. This is done by incorporating zinc sulphate particles into the outermost elastomer layer. These particles are electroluminescent, meaning they light up in the presence of an electric field – in this case, the one coursing through the carbon nanotube layers.
Changing the chemistry of the zinc particles causes them to glow in different colors, which the team used to make green, orange and blue variations. They also made multiple masking layers to create light patterns that flashed in the shape of the letters M, I and T.
The glow was added at little cost to the robot, requiring just three percent more energy and adding 2.5 percent more weight overall, the team says.
Making these robots glow isn’t just about making them prettier. The researchers say that these flashing lights could be used to track the robots in outdoor environments, or to allow a swarm of them to communicate with each other, since they won’t be able to carry much electronic machinery.
In tests, the team showed that the flashy fliers could be tracked using simple smartphone cameras and custom software, which detected the different light colors and pinpointed the positions of the robots to within 2 mm.
In future work, the researchers plan to investigate ways to allow the robots to turn their lights on and off, allowing more detailed communication.
The research was published in the journal IEEE Robotics and Automation Letters. The team demonstrates the firefly robots in the video below.