The new work builds on the team’s previous development of ultralight flying robots that are reasonably durable for their size. The key ingredient in the earlier work was a soft actuator, which consisted of a thin cylinder composed of alternating layers of elastomer and carbon nanotubes. When a voltage is applied, the carbon electrodes squeeze the elastomer, creating mechanical strain that causes the wing to flap.
In the new study, the researchers modified these actuators so that they also emit light when they work. This is achieved by incorporating zinc sulfate particles into the outermost elastomeric layer. The particles are electroluminescent, which means they emit light in the presence of an electric field — in this case, an electric field that passes through the carbon nanotube layer.
Changing the chemical composition of the zinc particles made them glow different colors, and the team used it to create green, orange and blue variations. They also made multiple masking layers to create patterns of light that flicker in the shape of the letters M, I and T.
Adding the light-emitting capability is inexpensive for the robot, the team said, requiring only a 3 percent increase in energy and an overall 2.5 percent increase in weight. Making these robots shine isn’t just about making them prettier. The researchers say these flashing lights could be used to track robots in outdoor environments, or to allow swarms of robots to “communicate” with each other, since they can’t carry much electromechanics.
In tests, the team showed that simple intelligence can be usedcell phoneCameras and custom software to track these shiny flying vehicles detect different light colors and pinpoint the robot’s position to within 2mm.
In future work, the researchers plan to analyze how to get robots to turn their lights on and off, allowing for more detailed communication.
The study was published inIEEE Robotics and Automation Communications” magazine. The team showcases the Firefly robot in the video below.