Research team develops automated material that needs no clock or central control

Researchers have developed a mechanical material capable of synchronizing the motion of 37 connected units, transforming minute vibrations into a coordinated rhythm without external timing signals. The international team constructed a two-dimensional honeycomb structure containing 37 active units, as well as a separate elastic ring with 24 motor units. Both structures developed repeating motion patterns through interactions among their components. The researchers describe this behavior as a form of time crystal, in which a system develops repeating patterns in time. Unlike conventional crystals, whose atomic structures repeat in space, these experimental materials likewise exhibit organized motion over time.

This work involves researchers from Amsterdam, Leiden, Birmingham, and other European institutions, and could ultimately help engineers develop mechanical materials capable of changing shape and coordinating motion without relying on a central controller.

Self-organizing properties of the material

Vibrations merge into a rhythm; this experimental material combines elastic structures, sensors, electronic components, and actuators. Actuators convert electrical energy into physical motion, enabling individual components to move and influence their neighboring units. The interactions designed by the researchers are asymmetric, meaning that when one component affects another, the second does not necessarily produce an equal response. This difference proved important. In the honeycomb structure, individual units initially oscillated at a frequency of about 30 hertz, or 30 times per second. Over time, these vibrations merged into larger patterns with longer wavelengths and periods, until the entire structure moved in unison.

The researchers call this process 'wave coarsening.' The system develops an organized rhythm through interactions built into the material, without external signals to synchronize each component. The team also tested a ring structure containing 24 motor units. Higher-frequency deformation modes initially appeared around the ring, then gradually merged into larger movements. Eventually, the ring settled into a slower repeating cycle. Experiments showed that the collective pattern remained stable under random perturbations. The researchers also used mathematical modeling to examine how ordered motion behaves as the system scales up.

Potential for future applications

These findings suggest a possible way to build mechanical structures that coordinate motion through their physical design, rather than by issuing commands to each component.

'Our work provides a striking example of self-organization — minute vibrations self-organize until the entire material moves in a coordinated fashion,' said Jack Binysh, co-lead author from the University of Birmingham. The experimental structures contained more than 100 sensors and actuators, along with 3D-printed parts and custom-built Lorentz actuators that use electromagnetic force to generate mechanical motion.

The researchers envision future materials capable of switching between different stable motion patterns. Such structures could eventually change shape or move in different directions without needing separate mechanical systems for each function. However, the experiments demonstrate coordinated oscillations, not robots capable of performing multiple practical tasks. The researchers have not yet demonstrated control over switching between different motion patterns for useful robotic manipulation. The team plans to study three-dimensional structures that can support more complex motions, including bending, twisting, and shearing. The findings have been published in the journal Nature.

Potential of automated materials without central control

This research demonstrates the self-organizing capability of mechanical materials to coordinate motion without central control. This has significant implications for future engineering design, as it can reduce reliance on complex control systems, thereby simplifying the design and manufacturing of mechanical structures. Although current experiments focus primarily on coordinated oscillations, potential future multifunctional applications will open new directions for various industries and robotics technologies. Further exploration by researchers promises to realize more complex motion patterns, advancing the development of automated materials.