Researchers at Cornell University and the Max Planck Institute for Intelligent Systems have made an exciting breakthrough in the field of microrobotics.
By mixing different sizes of micron-scale robots, they have discovered a way to enable these tiny machines to self-organize into diverse patterns.
Moreover, the researchers found that applying a magnetic field allows the swarm to manipulate objects, even trapping and expelling them. These findings could have profound implications for future applications, such as targeted drug delivery in the human body.
The study, titled “Programmable Self-Organization of Heterogeneous Microrobot Collectives,” was published in the Proceedings of the National Academy of Sciences.
The lead author, Steven Ceron, Ph.D., worked under the guidance of Kirstin Petersen, an assistant professor at Cornell Engineering.
Petersen’s Collective Embodied Intelligence Lab has been exploring various methods to enable large groups of robots to behave intelligently. However, extending these approaches to microscale technologies has been challenging due to the limited computational capacity of such small robots.
To overcome this obstacle, Ceron and Petersen collaborated with Gaurav Gardi and Metin Sitti from the Max Planck Institute for Intelligent Systems. Gardi and Sitti specialize in developing microscale systems driven by magnetic fields.
The researchers used 3D-printed polymer discs as their microrobots. These tiny discs, roughly the width of a human hair, were coated with a thin layer of ferromagnetic material and placed in a pool of water.
By applying two orthogonal external oscillating magnetic fields and adjusting their parameters, the researchers were able to induce spinning motion in each microrobot, generating magnetic, hydrodynamic, and capillary forces.
By employing microrobots of different sizes, the team successfully controlled the swarm’s self-organization and behavior.
They achieved various outcomes, such as changing the shape of the swarm from circular to elliptical, clustering similarly sized microrobots into subgroups, and adjusting the spacing between individual microrobots to capture and expel external objects as a collective.
One exciting application of this research is the potential for targeted drug release. By employing microrobots that can carry pharmaceutical products within the human body, specific locations can be targeted for drug delivery.
The microrobots could transport medicine to the intended site and release it in a controlled manner.
Petersen explained, “In the behaviors of these microscale systems, we’re starting to see a lot of parallels to more sophisticated robots despite their lack of computation, which is pretty exciting.”
To understand and characterize the asymmetric interactions between different-sized microrobots, Ceron and Petersen developed a model called the “swarmalator.” This model helps explain the self-organization of the microrobots and holds the potential to predict new swarming behaviors.
Ceron, now a postdoctoral fellow at the Massachusetts Institute of Technology, said, “With the swarmalator model, we can summarize the physical interactions between microrobots and apply it to different microrobot swarms.
This opens up possibilities for developing and studying collective behaviors in magnetic microrobots and predicting behaviors in future microrobot designs.”
This study represents a significant step toward harnessing the potential of microrobots and exploiting their heterogeneity to achieve complex collective behaviors.
The researchers hope to continue exploring and refining these fascinating microscale systems, paving the way for even more groundbreaking advancements in the future.
