Say hello to the world’s smallest remote-controlled robot—just half a millimeter wide. Shaped like a tiny crab and smaller than a flea, this miniature marvel can bend, twist, crawl, walk, turn, and even leap into the air. It’s a stunning display of advanced micro-robotics! The research is published in the journal Science Robotics.

Pushing the Limits of Microscale Robotics

“Robotics is an exciting field of research, and the development of microscale robots is a fun topic for academic exploration,” said John A. Rogers, who led the experimental work. “You might imagine microrobots as agents to repair or assemble small structures or machines in industry or as surgical assistants to clear clogged arteries, to stop internal bleeding or to eliminate cancerous tumours – all in minimally invasive procedures.”

“Our technology enables a variety of controlled motion modalities and can walk with an average speed of half its body length per second,” added Yonggang Huang, who led the theoretical work.  “This is very challenging to achieve at such small scales for terrestrial robots.”

From Concept to Motion

The robots, which are made of a malleable shape-memory alloy, start as flat objects, similar to a piece of paper. The legs and arms are bent so the robot can stand, he said. The crab stays standing on its legs until heat is used to get the crab to move. 

Rogers explained that a metallic object made from shape-memory alloy can be bent or twisted, but when heat is applied, it returns to its original shape, almost like magic. The "crab" stays standing on its legs until the heat from the lasers is used to get the crab to move. “A laser is a convenient way to do it because we can focus the light to a very tiny spot, and we can scan that spot around to illuminate different parts of the robot’s body in a time sequence,” he said.

Small Robots, Big Potential

Rogers mentioned that the robots are currently in the development stage and primarily intended for educational purposes. However, the technology behind these miniature, crab-like robots holds significant promise. In the future, they could assist with minimally invasive surgical procedures or aid in the assembly and maintenance of small-scale machinery.

“As an aspirational goal, I asked the students to see if they could come up with a way to make these robots take flight – maybe impossible, but fun to think about,” he said.