This 'Brainless' Soft Robot Can Navigate Mazes Without Human Direction—How?

Researchers have achieved a notable advancement in the field of soft robotics by creating a "brainless" robot capable of autonomously navigating complex environments, including dynamic obstacles and intricate mazes.

This breakthrough, developed by scientists at North Carolina State University, builds upon their prior work in which they demonstrated a soft robot's ability to maneuver through simple obstacles without human or computer guidance.

Robot 'Physical Intelligence'

The latest iteration utilizes the concept of "physical intelligence," a term denoting dynamic objects, like soft robots, whose behavior is determined by their structural composition and the materials they are constructed from, rather than being reliant on computer or human instructions.

"We've developed a new soft robot that is capable of turning on its own, allowing it to make its way through twisty mazes, even negotiating its way around moving obstacles. And it's all done using physical intelligence, rather than being guided by a computer," said Jie Yin, co-corresponding author of a paper on the work and an associate professor of mechanical and aerospace engineering at North Carolina State University.

These soft robots are constructed from ribbon-like liquid crystal elastomers. When placed on a surface exceeding 55°C (131°F), the section in contact with the surface contracts while the exposed part does not, resulting in a rolling motion. The hotter the surface, the faster the robot rolls.

In contrast to its predecessor, the new robot boasts an asymmetrical design with two distinct halves. One half takes the form of a twisted ribbon extending in a linear fashion, while the other resembles a tightly twisted ribbon, coiling around itself like a spiral staircase.

This asymmetry leads to one end of the robot exerting greater force on the ground than the other, akin to a plastic cup with a wider mouth than the base, causing it to travel in an arc rather than a straight line.

Robot Asymmetry

Yao Zhao, the paper's first author, explained that the robot can turn without direct contact with an object due to its asymmetry. While it does change direction upon encountering an obstacle, preventing it from becoming trapped between parallel objects, its capacity to move in arcs allows it to navigate through intricate spaces.

"So, while it still changes directions when it 'does' come into contact with an object-allowing it to navigate mazes-it cannot get stuck between parallel objects. Instead, its ability to move in arcs allows it to essentially wiggle its way free," Zhao said in a statement.

The team carried out experiments to showcase the robot's proficiency in maneuvering through intricate mazes, some of which featured dynamic walls and traversing spaces narrower than its own dimensions. These trials took place on various surfaces, including metal and sand.

According to Yin, this achievement represents a significant step in the evolution of soft robot design, particularly for applications where these robots could harness heat energy from their environment. The findings of the study were recently published in the journal Science Advances.