Mapping Unknown Environments With Twisted Ringbots

Researchers at North Carolina State University (NCSU) have developed new soft, autonomous robots –  called twisted ringbots – that could be used to efficiently navigate and map unknown environments.

The twisted ringbots are capable of three simultaneous behaviors: rolling forward; spinning like a record; and following a path that orbits around a central point. They are made of ribbon-like liquid crystal elastomers that are twisted and then joined together to form a loop. When the robots are placed on a surface that is at least 55° C (131°F), the portion of the ribbon touching the surface contracts, while the portion of the ribbon exposed to the air remains unchanged. This induces a rolling motion, with the robot rolling faster with increased warming of the surface. Its movement is governed by physical intelligence, in that its actions are determined by its structural design and the materials it’s made of rather than being directed by a computer or human intervention.

The twisted ringbot travels in a large circular manner by rolling on its horizontal axis for forward momentum, spinning along its central axis, and moving in an orbital path around a central point. When it encounters a boundary, such as a wall, it will travel along the boundary. 

“Regardless of where the twisted ringbot is introduced to these spaces, it is able to make its way to a boundary and follow the boundary lines to map the space’s contours – whether it’s a square, a triangle, and so on,” said Fangjie Qi, a Ph.D. student at NC State. “It also identifies gaps or damage in the boundary.

Proof-of-concept testing demonstrated that the twisted ringbot could navigate through confined spaces by following its contours. The researchers were also able to map the boundaries of more complex spaces by introducing two twisted ringbots into the space, with each robot rotating in a different direction. 

“In principle, no matter how complex a space is, you would be able to map it if you introduced enough of the twisted ringbots to map the whole picture, each one giving part of it,” said Jie Yin, corresponding author of the paper. “And, given that these are relatively inexpensive to produce, that’s viable.”

A video of the twisted ringbot can be found here: