Imagine tiny robots, smaller than a grain of salt, working together like a perfectly synchronized stadium wave.
Cornell University researchers have created microscopic machines that can coordinate their movements using electronic signals.
This breakthrough could revolutionize fields like drug delivery, chemical mixing, and cleaning up pollution.
These micromachines, developed by a team led by professors Alyssa Apsel and Itai Cohen, are unique because they can synchronize themselves without any central control.
The research, published in Science Robotics, is the first to show this kind of synchronization in machines powered by special circuits called complementary metal-oxide-semiconductor oscillators.
Each tiny machine has a "bending paddle" actuator only 7 nanometers thick. When activated, it moves up and down, similar to how people stand and sit to create a wave at a sports event.
The machines communicate with each other by sending electronic pulses.
These signals help them match their timing with the fastest machine in the group, creating a perfectly synchronized movement.
"The oscillators are very low power, using less than a nanowatt of energy, and they're simple to operate," Apsel explained. "We're designing timing systems that talk to each other to create global coordination. This is ideal for tiny machines that can't be wired or powered like larger devices."
The synchronization method is inspired by natural systems, such as fireflies blinking together or heart cells beating in unison. Using a technique called pulsed coupling, the machines send signals to adjust their timing with their neighbors. This decentralized approach allows them to self-correct if conditions change, or if the group splits into smaller clusters. When reconnected, the machines can seamlessly resynchronize.
The team successfully tested arrays of up to 16 machines in both straight lines and two-dimensional patterns. They believe this system can easily be scaled up to manage even larger swarms of microrobots. This scalability could enable these tiny robots to perform complex tasks, like delivering medicine inside the human body, mixing chemicals more efficiently, or even cleaning up environmental waste.
Looking ahead, the researchers plan to create more advanced microrobots, such as ones that move like inchworms or can split into smaller groups to work independently.
"This research shows how we can take ideas from biology and use them to solve engineering challenges," Apsel said. "We've made incredible progress in building tiny machines that can move and sense their surroundings. Now, we've found a simple but powerful way to make them work together."
This innovation could open the door to entirely new types of materials and machines, transforming industries and improving lives.