Researchers Build Robot from Multiple 3D-Printed Smaller Ones

Researchers from Georgia Institute of Technology have built a robot that consists entirely of smaller ones known as “smarticles.” This new locomotion technique challenges the conventional way of creating robots from motors, batteries, actuators, body segments, legs, and wheels. 

The new research was supported by the Army Research Office, the National Science Foundation, and researchers from Northwestern University. It was published in the journal Science Robotics. 

These 3D-printed smart active particles can only perform the function of flapping their two arms. The potential of these smarticles changes whenever there are five of them confined in a circle. When together, they form a robophysical system called a “supersmarticle” by nudging one another.  This supersdmarticle is then able to move independently. If a sound or light sensor is added, it is then able to be controlled through stimulus. 

This new system is still in its infancy, but the idea of creating robots from grouping together smaller ones has huge potential. It provides group capabilities, and it could lead to mechanically based control over small robots. The grouping of smaller robots could also lead to a new locomotion.

Dan Goldman is a Dunn Family Professor in the School of Physics at the Georgia Institute of Technology. 

“These are very rudimentary robots whose behavior is dominated by mechanics and the laws of physics,” he said. “We are not looking to put sophisticated control, sensing and computation on them all. As robots become smaller and smaller, we'll have to use mechanics and physics principles to control them because they won't have the level of computation and sensing we would need for conventional control.”

The research was built upon the study of construction staples that were poured into a container with removable sides. A former PhD student and now a faculty member at the University of California San Diego, Nick Gravish, then removed the container’s walls to create structures that could stand alone. He realized that mechanical objects could be put together in order to create structures that could do a lot more than their individual components. 

“A robot made of other rudimentary robots became the vision,” Goldman said. “You could imagine making a robot in which you would tweak its geometric parameters a bit and what emerges is qualitatively new behaviors.”

Will Savoie, a graduate research assistant, created battery-powered smarticles from a 3D printer. They had motors, simple sensors, and some computing power. Individually, the smarticles can’t do much, but they are able to change location and interact with one another when put in a ring. 

“Even though no individual robot could move on its own, the cloud composed of multiple robots could move as it pushed itself apart and shrink as it pulled itself together,” according to Goldman. “If you put a ring around the cloud of little robots, they start kicking each other around and the larger ring — what we call a supersmarticle — moves around randomly.”

The researchers also learned that they could control the movement of the robots by using photo sensors. They were able to stop the arms from flapping with a beam of light. 

“If you angle the flashlight just right, you can highlight the robot you want to be inactive, and that causes the ring to lurch toward or away from it, even though no robots are programmed to move toward the light,” Goldman explained. “That allowed steering of the ensemble in a very rudimentary, stochastic way.”

These new developments will help in the creation of swarm robots that are made up of multiple smaller devices. They could be altered so that they are useful in a variety of different situations and applications. The U.S. Army has also taken an interest in the new project since it could help create shape-changing robots which can alter their modalities and functions.