Scientists have invented groups of tiny magnetic robots that function in unison similar to ants, enabling them to accomplish remarkable tasks, such as moving and lifting objects significantly larger than themselves. Research indicates that these microrobot swarms, which operate in a rotating magnetic field, may be capable of tackling challenging assignments in tough environments, where individual robots would face difficulties, including minimally invasive treatments for blocked arteries and accurately directing small organisms.
Researchers in South Korea have created swarms of minute magnetic robots that collaborate like ants to accomplish extraordinary feats, such as navigating and lifting objects much larger than they are.
These findings, released on Wednesday, December 18 in the cell Press journal Device, imply that these microrobot swarms—functioning under a rotating magnetic field—could be utilized for complex tasks in demanding settings that single robots would find hard to manage, like providing less invasive options for treating clogged arteries and guiding organisms with precision.
“The remarkable adaptability of microrobot swarms to their environment and their high level of autonomous control over the swarm were unexpected,” stated Jeong Jae Wie, one of the authors from the Department of Organic and Nano Engineering at Hanyang University in Seoul, South Korea.
Wie and their team examined the effectiveness of microrobot swarms with various assembly patterns across different tasks. They discovered that those with high aspect ratio arrangements could ascend obstacles five times the length of one microrobot and launch themselves, one at a time, over barriers.
A substantial group of 1,000 tightly packed microrobots formed a raft that floated on water and encased a pill weighing 2,000 times more than each individual robot, which allowed the swarm to move the medication through the liquid.
On solid ground, a robot swarm successfully carried cargo weighing 350 times more than each individual robot, while another swarm of microrobots was able to clear blocked tubes that resembled obstructed blood vessels. Finally, using spinning and orbital movements, Wie’s team established a mechanism that allowed robot swarms to steer the motions of small living organisms.
There is growing scientific interest in how robotic swarms can collaboratively meet objectives, inspired by the collective behavior of ants who unite to bridge gaps or form rafts to survive floods. Similarly, teamwork increases the robots’ resilience to failure; even if some in the group don’t achieve the objective, the others continue executing their programmed actions until enough achieve success.
“Past research in swarm robotics has mainly focused on spherical robots that connect via point-to-point contact,” according to Wie. In this study, the researchers designed a swarm using cube-shaped microrobots, whose larger surface area allows for stronger magnetic attractions as entire faces of each cube can connect.
Each microrobot measures 600 micrometers in height and consists of an epoxy body containing ferromagnetic neodymium-iron-boron (NdFeB) particles, allowing it to respond to magnetic fields and interact with other microrobots. By inducing a magnetic field through rotating two interconnected magnets, the swarm can assemble itself. The researchers programmed the robots to join in various configurations by altering the angle at which they were magnetized.
“We established an affordable mass production process using onsite replica molding and magnetization to ensure consistent size and magnetic properties for reliable performance,” says Wie.
“While the results of this study are encouraging, the swarms will require improvements in autonomy before they can be applied in real-world situations,” Wie explains.
“The magnetic microrobot swarms depend on external magnetic control and currently cannot navigate complex or confined areas like actual arteries independently,” he continues. “Future research will aim to enhance the autonomy of the microrobot swarms, through features like real-time feedback control of their movements and paths.”
