Tiny 3D Printed Robots Are Nearly Invisible

Scientists are working hard to perfect tiny robots that can work with more of their kind to perform tasks on a larger scale. The tiny robot seen below was created by Georgia Tech and is called micro-bristle-bot. The scientists say that these tiny robots might one day work in groups to sense environmental changes, move materials, and possibly one day repair injuries inside the human body.

The prototype robots are designed to respond to different vibration frequencies depending on their configurations. The different vibrations they respond to allow researchers to control individual bots by adjusting the vibration frequencies. The minuscule little robots are only about two millimeters long, which is about the size of the world's smallest ant.

Despite their small size, the micro-bristle-bots can cover four times their own length in a second. The bots have a piezoelectric actuator glued onto a polymer body that is 3D printed using two-photon polymerization lithography. The small actuator generates vibration and is powered externally because there are no batteries small enough to fit onto the robot.

Vibrations can come from a piezoelectric shaker under the surface the robots are moving on. The vibrations move the springy legs of the bot's legs up and down to push the robot forward. The amplitude of the vibration controls the speed that the robots move.

The tiny robots are made in a 3D printer using the TPP process that polymerizes a monomer resin material. Once the portion of the resin block hit by the UV light has been chemically developed, the remainder can be washed away leaving the robotic structure behind. Scientists say that it's writing rather than traditional lithography as you are left with the structure you write with the laser on the resin material. The piezoelectric actuators can also generate a voltage when vibrated to run sensors on the device.