Pulse coupled oscillators for micromachines*

Microrobots are becoming increasingly functional and are poised to significantly impact various technical domains, including targeted drug delivery, precise surgical interventions, and environmental remediation. However, unlocking even greater potential lies in the ability of these microscopic robots to coordinate their actions and cooperate effectively. Achieving this coordination, however, presents a formidable challenge, primarily centered around the need for a scalable synchronization strategy—a crucial hurdle to overcome for enabling collective behaviors in multiple autonomous microscopic robots.

In this context, we introduce pulse-coupled CMOS oscillators as a practical solution for achieving scalable synchronization. Our approach involves low-power oscillating modules equipped with mechanical elements that exchange electronic pulses, thereby advancing their neighboring modules' phases until the entire system achieves synchronization with the fastest oscillator. Importantly, this synchronization strategy is adaptable to different oscillator connection topologies, exhibits robustness against disturbances, and, intriguingly, allows subgroups to self-synchronize when connections between oscillators are severed.

This breakthrough opens up exciting possibilities for microscopic robot swarms, ranging from autonomously inducing fluidic transport to driving chemical reactions to the collaborative construction of physical structures at the microscale.