The short version
- Physicists built a honeycomb of 37 small robotic units whose vibrations merged on their own into one slow, shared rhythm.
- The trick was one-way coupling, where each unit pushes its neighbor differently from how the neighbor pushes back.
- The team sees uses in robotics and shape-changing materials, though practical applications are some way off.
Physicists from the Universities of Birmingham, Amsterdam, Lyon, Delft, Leiden and Cambridge report in Nature that a vibrating material can organize itself into a time crystal, a system that repeats in time the way a crystal repeats in space. They built a flat honeycomb of 37 active units, each with springy hexagons, sensors, motors and a small controller. The coupling between units was one-way: squeezing one unit squeezes its neighbor on one side and stretches the one on the other. Pushed past a threshold, each unit began buzzing at around 30 Hz. Then the short, fast vibrations merged into longer, slower and larger waves until the whole structure moved as one. The team calls this “wave coarsening.” A ring of 24 motorized units showed the same merging.
“Like musicians gradually finding the same beat,” says Jack Binysh of Birmingham. Simulations suggest the shared rhythm would hold even in a much larger material. Adding friction in the model instead left waves running one way around the edge. The journal page would not open here, and the work first appeared as a preprint in August 2025.
The authors point to robotics and shape-changing materials. ScienceAlert notes that practical applications are “some way off.”
