Despite being smaller than a flea, he has multiple abilities. Because size is not everything. The mini robot crab, just 0.55 mm wide and developed by researchers at Northwestern University, is capable of bending, turning, crawling and even jumping.
What could this little walking robot be used for?
“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 can imagine microrobots as agents to repair or assemble small structures or machines in industry or as surgical assistants to clear clogged arteries, stop internal bleeding, or remove cancerous tumors, all in minimally invasive procedures.”
“Our technology enables a variety of controlled movement 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 difficult for ground-based robots to achieve at such small scales .”
As the researchers explain, the robotic crab does not work with complex hydraulic or electrical hardware, but rather relies on the elastic resistance of its body.
Designing a little robot
To develop the robot, the team used a memory alloy material so that it transforms into its ‘remembered’ shape when heated. This is coated with a thin layer of glass, which returns the robot to its deformed shape when it cools down.
“Because these structures are so small, the rate of cooling is very fast ,” Rogers explained. “In fact, reducing the size of these robots allows them to run faster.”
The technology behind the robot was originally developed eight years ago: the robot’s parts are attached to a stretched rubber substrate, and when the material relaxes, the device takes its shape. Thus, when the stretched substrate relaxes, a controlled buckling process occurs that causes the crab to “jump” into precisely defined three-dimensional shapes.
“With these assembly techniques and material concepts, we can build walking robots with almost any size or 3D shape,” continues the expert. “But the students were inspired and amused by the lateral movements of the little crabs. It was a creative whim.”
Referencia: Mengdi Han, Xiaogang Guo, Xuexian Chen, Cunman Liang, Hangbo Zhao, Qihui Zhang, Wubin Bai, Fan Zhang, Heming Wei, Changsheng Wu, Qinghong Cui, Shenglian Yao, Bohan Sun, Yiyuan Yang, Quansan Yang, Yuhang Ma, Zhaoguo Xue, Jean Won Kwak, Tianqi Jin, Qing Tu, Enming Song, Ziao Tian, Yongfeng Mei, Daining Fang, Haixia Zhang, Yonggang Huang, Yihui Zhang, John A. Rogers. Submillimeter-scale multimaterial terrestrial robots. Science Robotics, 2022 ; 7 (66) DOI: 10.1126/scirobotics.abn0602