Microrobot swarms, driven by a rotating magnetic field, have the potential to handle complex tasks in challenging environments. (Representational image)
South Korean researchers have created tiny magnetic robots that collaborate like ants, accomplishing impressive tasks such as moving and lifting objects far larger than themselves.
The team at Hanyang University in Seoul, South Korea, suggests their microrobot swarms, powered by a rotating magnetic field, could tackle challenging tasks in difficult environments.
These tasks include offering minimally invasive treatments for clogged arteries and precisely guiding organisms.
“The high adaptability of microrobot swarms to their surroundings and high autonomy level in swarm control were surprising,” said Jeong Jae Wie, part of the Department of Organic and Nano Engineering at Hanyang University, in a statement.
Magnetic swarms assemble
Scientists are increasingly studying how robot swarms can collectively achieve goals, drawing inspiration from ants that work together to bridge gaps or form rafts to survive floods. The cooperative approach makes robots more resilient to failure, as even if some fall short, the others continue their programmed actions until enough succeed.
Previous research in swarm robotics focused on spherical robots that connect via point-to-point contact. In this study, the researchers designed a swarm of cube-shaped microrobots, which have stronger magnetic attraction due to the larger surface areas of their faces coming into contact.
Above-water drug transportation using robotic swarms.
Each of the team’s microrobots is 600 micrometers tall, made of epoxy embedded with ferromagnetic neodymium-iron-boron (NdFeB) particles, allowing it to respond to magnetic fields and interact with others. Powered by a rotating magnetic field from two connected magnets, the swarm can self-assemble.
The researchers programmed the robots to form different configurations by adjusting the magnetization angle, enabling them to come together in various patterns. The design allows for precise control over the swarm’s behavior, enhancing its ability to perform complex tasks collectively.
“We developed a cost-effective mass production method using onsite replica molding and magnetization, ensuring uniform geometry and magnetization profiles for consistent performance,” added Wie.
Microrobots show versatility
Researchers tested microrobot swarms with different assembly configurations to evaluate their performance in various tasks. They discovered that swarms with a high aspect ratio could climb obstacles five times taller than the height of a single microrobot and throw themselves over obstacles, one at a time.
In a demonstration involving 1,000 microrobots with a high packing density, the swarm formed a raft that floated on water and wrapped around a pill weighing 2,000 times more than each robot, allowing it to transport the drug across the liquid. On land, the swarm successfully transported cargo 350 times heavier than the individual robots.
Another experiment showed how the robots could clear blocked tubes, simulating clogged blood vessels. Additionally, by using spinning and orbital dragging motions, the researchers developed a system where the robot swarm could control the movements of small organisms.
According to researchers, these experiments highlight the versatility of microrobot swarms, showcasing their potential for applications in drug delivery, cargo transport, and medical treatments.
“While the study’s results are promising, the swarms will need higher levels of autonomy before they will be ready for real-world applications,” concluded Wie.
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Currently, the magnetic microrobot swarms require external magnetic control and do not possess the ability to autonomously navigate complex or confined spaces, such as real arteries.
The team highlights that future research will focus on improving the autonomy of these microrobot swarms, including the development of real-time feedback control for their movements and trajectories.
The details of the team’s research were published in the Cell Press journal Device.
