Here is a bunch of tiny 3D-printed robots that move by harnessing vibration from piezoelectric actuators. They are the size of the world’s smallest ant. Swarms of these robots can work together to sense environmental changes and move materials.
As the researchers explain, these micro-bristle-bots “consist of a piezoelectric actuator glued onto a polymer body that is 3D-printed using two-photon polymerization lithography (TPP). The actuator generates vibration and is powered externally because no batteries are small enough to fit onto the bot. The vibrations can also come from a piezoelectric shaker beneath the surface on which the robots move, from an ultrasound/sonar source, or even from a tiny acoustic speaker.”
Vibrations move the legs up & down to propel the robot forward. The micro-bristle-bots measure 2mm in length and 1.8mm wide.