Scientists have taken inspiration from nature’s master communicators—like bats, whales, and insects—to design a new kind of microrobot that “talks” using sound.
These robots, though incredibly simple, can work together in large swarms to move, adapt, and even “heal” themselves after being damaged.
The research, led by Igor Aronson from Penn State University, was recently published in Physical Review X.
Imagine a swarm of bees or a school of fish, each member moving in harmony with the others. In the same way, these microrobots create and respond to sound waves, staying together and coordinating as if they share one mind.
Each robot is tiny—equipped with a motor, a small microphone, a speaker, and an oscillator that helps it stay in sync with the group’s collective “acoustic field.”
When the swarm moves, the robots follow the strongest sound signals, keeping them organized and responsive.
Although the current work was based on computer simulations rather than physical prototypes, the results were striking. Even with very basic designs, the robots showed a surprising level of group intelligence. The simulations suggest that, in real-world experiments, the same behavior would likely appear.
These sound-driven swarms could have many future uses. In environmental cleanup, they might navigate through polluted waterways to collect harmful materials.
In disaster zones, they could slip into tight spaces too dangerous for humans.
Inside the human body, swarms could deliver medicine directly to specific tissues, detect changes in their surroundings, or monitor for threats.
One of the biggest advantages of using sound, Aronson explained, is its efficiency. Previous “active matter” research—studying the collective behavior of microscopic agents—relied mostly on chemical signals to control movement.
But chemical signals spread slowly and lose strength over distance. Sound, by contrast, travels quickly and maintains energy over long ranges, making it ideal for communication.
The simplicity of each robot is key. None of them is “smart” on its own, but together, they act with remarkable coordination. They can reorganize if split apart, adapt to new environments, and carry out tasks without central control.
Aronson believes this minimalist approach could lead to highly effective tools for tackling complex problems in challenging settings.
The team’s findings mark the first time sound waves have been shown—at least in theory—to control microrobots in this way. Co-authors Alexander Ziepke, Ivan Maryshev, and Erwin Frey from Ludwig Maximilian University of Munich joined Aronson in the work.
“This is a big step toward creating smarter, more resilient microrobots,” Aronson said. “With just a few basic parts and acoustic communication, they can achieve a surprising level of collective intelligence.”
