37-unit robotic material synchronizes movement without a clock or central control

An international team built a robotic material in which a 2D honeycomb of 37 active units and a ring of 24 motorized units develop coordinated motion on their own. Units initially oscillated at about 30 Hz before vibrations merged into collective waves, a behavior the researchers call time crystallization. The work was published in Nature.

• 37-unit honeycomb and 24-unit ring synchronize without an external timing signal
• Initial 30 Hz oscillations merge into collective waves via "wave coarsening"
• Structures use over 100 sensors and actuators plus 3D-printed parts
• Next step: 3D structures supporting bending, twisting and shearing