Researchers at Penn State University have developed microscopic robots capable of communicating and coordinating their movements using sound waves. Published on August 12, 2025, in Physical Review X, this innovation allows these tiny machines to autonomously form intelligent swarms, inspired by the acoustic communication observed in nature, such as in bats and whales.
Each microrobot is equipped with a motor, microphone, speaker, and oscillator, enabling them to synchronize with the collective "acoustic field" of the swarm. This facilitates coordinated movements and behaviors without the need for complex central programming. Simulations have demonstrated a high level of collective intelligence, mirroring the sophisticated coordination seen in natural phenomena like flocks of birds or schools of fish. Professor Igor Aronson of Penn State likens their operation to these natural swarms, where individual movements create a soundscape that maintains group cohesion. The simplicity of each robot's design enhances their resilience and adaptability, allowing swarms to reorganize if separated, adapt to new environmental conditions, and perform tasks collectively without a single point of control. This robustness is crucial for operations in challenging or hazardous environments. Sound communication offers advantages over other methods, as sound waves can maintain energy over longer distances compared to slower chemical signals, facilitating efficient coordination of large groups for applications requiring synchronized action across a broad area. Potential applications include environmental cleanup, navigating disaster zones for information gathering or rescue operations, and highly targeted medicine delivery within the human body. The ability to adapt their shape and behavior, forming structures like snakelike entities or clusters, further enhances their utility in complex scenarios. This pioneering research, with co-authors including Alexander Ziepke, Ivan Maryshev, and Erwin Frey from Ludwig Maximilian University of Munich, represents a substantial leap forward in creating smarter, more resilient microrobots capable of complex tasks and responsive behavior in dynamic environments.