Scientists Create World’s Tiniest Remote-Controlled Walking Robot | Sci-News.com

2022-05-28 11:49:08 By : Ms. Lan Xu

Just 0.5 mm wide, the tiny walking robot developed by Northwestern University’s Professor John Rogers and his colleagues can bend, twist, crawl, walk, turn and even jump.

Han et al. developed the smallest-ever remote-controlled walking robot. Image credit: Han et al., doi: 10.1126/scirobotics.abn0602.

“Robotics is an exciting field of research, and the development of microscale robots is a fun topic for academic exploration,” Professor Rogers said.

“You might imagine micro-robots 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 tumors — 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. This is very challenging to achieve at such small scales for terrestrial robots,” added Northwestern University’s Professor Yonggang Huang.

The team’s tiny robot is not powered by complex hardware, hydraulics or electricity. Instead, its power lies within the elastic resilience of its body.

To construct the robot, the researchers used a shape-memory alloy material that transforms to its ‘remembered’ shape when heated.

In this case, they used a scanned laser beam to rapidly heat the robot at different targeted locations across its body. A thin coating of glass elastically returns that corresponding part of structure to its deformed shape upon cooling.

As the robot changes from one phase to another — deformed to remembered shape and back again — it creates locomotion.

Not only does the laser remotely control the robot to activate it, the laser scanning direction also determines the robot’s walking direction.

Scanning from left to right, for example, causes the robot to move from right to left.

“Because these structures are so tiny, the rate of cooling is very fast. In fact, reducing the sizes of these robots allows them to run faster,” Professor Rogers said.

To manufacture such a tiny robot, the scientists turned to a technique they introduced eight years ago — a pop-up assembly method inspired by a child’s pop-up book.

First, they fabricated precursors to the walking crab structures in flat, planar geometries.

Then, they bonded these precursors onto a slightly stretched rubber substrate.

When the stretched substrate is relaxed, a controlled buckling process occurs that causes the crab to ‘pop up’ into precisely defined 3D forms.

With this manufacturing method, the authors could develop robots of various shapes and sizes.

“With these assembly techniques and materials concepts, we can build walking robots with almost any sizes or 3D shapes,” Professor Rogers said.

“But the students felt inspired and amused by the sideways crawling motions of tiny crabs. It was a creative whim.”

The team’s paper was published in the journal Science Robotics.

Mengdi Han et al. 2022. Submillimeter-scale multimaterial terrestrial robots. Science Robotics 7 (66); doi: 10.1126/scirobotics.abn0602