Thirty-seven small robots linked together eventually move at the same pace, without any leader setting the rhythm.
At first, their movements are disordered. Some vibrate in one direction, others in another, and small waves travel through the whole structure. Then the waves grow, the movements slow down, and the entire structure eventually deforms according to the same regular rhythm.
Experimental setup of the mechatronic metamaterial made up of 37 elements and evolution of its vibrations.
Source: Nature (2026), figure 1, DOI 10.1038/s41586-026-11163-6.
This remarkable experiment was carried out by a team of researchers from several European universities, including in Amsterdam. The 37 elements form something like a flexible surface. Each one has sensors and a motor, and is connected to its neighbors by elastic components. So these are not 37 autonomous robots moving around a room, but small modules forming a single material.
When one module pushes its neighbor, the latter does not necessarily respond with the same force in the opposite direction. The researchers deliberately created this imbalance, which allows small vibrations to develop instead of disappearing.
Once the device is powered, no central program sets the rhythm for the whole system. Each module reacts mainly to what is happening around it. Over time, the small waves give way to increasingly broad movements, until the entire surface takes part in the same oscillation.
In physics, this is called a “time crystal.” In an ordinary crystal, such as salt, atoms form a pattern that repeats in space. Here, it is the movement that repeats regularly over time. This repetition remains stable even when the system is slightly disturbed.
The researchers also observed this phenomenon in another structure, this time made up of a chain closed in on itself.
Why seek to achieve this behavior? Today, many robots need a system that controls each of their movements. A system whose elements organize themselves could simplify certain soft machines capable of changing shape or moving.
For now, this is a laboratory demonstration. The researchers want to understand how to obtain several stable movements and move to three-dimensional structures. This could be a step toward robots whose bodies themselves contribute to organizing their movements.