Matt Shipman
Researchers who created a soft robot that can navigate a simple maze without human or computer direction have now built on that work to create a “brainless” soft robot that can navigate more complex and dynamic environments.
“In our initial work, we demonstrated that soft robots can navigate very simple obstacle courses,” says Jie Yin, associate professor of mechanics and aerospace studies and co-corresponding author of a paper on the work. in Engineering from North Carolina State University. “But I couldn’t change direction unless I encountered an obstacle. In practice, this means that the robot can sometimes bounce back and forth between parallel obstacles and get stuck.
“We have developed a new soft robot that can rotate on its own, allowing it to navigate through twisty mazes and even navigate moving obstacles. And all of this is done using physical intelligence rather than being guided by a computer.”
Physical intelligence refers to dynamic objects, such as soft robots, whose behavior is determined by their structural design and materials of construction rather than being dictated by computer or human intervention.
Like its predecessor, the new soft robot is made of ribbon-shaped liquid crystal elastomer. When a robot is placed on a surface that is hotter than the surrounding air (over 55 degrees Celsius (131 degrees Fahrenheit)), the portion of the ribbon that touches the surface contracts, while the portion of the ribbon that is exposed to the air contracts. no. This induces a rolling motion. The warmer the surface, the faster the robot will roll.
But while previous versions of the soft robot had a symmetrical design, the new robot has two distinct halves. Half of the robot is shaped like a straight twisted ribbon, while the other half is shaped like a more tightly twisted ribbon that winds around itself like a spiral staircase.
This asymmetric design means that one end of the robot exerts more force on the ground than the other end. Think of a plastic cup with a mouth wider than the bottom. When you roll it across a table, it doesn't roll in a straight line, but rather makes an arc as it moves across the table. The reason is its asymmetrical shape.
“The concept behind our new robot is very simple: its asymmetric design allows it to rotate without making contact with an object,” said Yao Zhao, a postdoctoral researcher at NC State and first author on the paper. “So you can navigate the maze by changing direction when you come into contact with an object, but you can’t get caught between parallel objects. Instead, their ability to move in an arc allows them to move essentially freely.”
Researchers demonstrated the ability of an asymmetric soft robot design to navigate more complex mazes, including one with moving walls, and to move through spaces narrower than its body size. Researchers tested the new robot design on metal surfaces and sand.
“This research is another step to help develop innovative approaches to soft robot design, especially for applications where soft robots can harvest thermal energy from their surroundings,” says Yin.
The paper, “Physically Intelligent Autonomous Soft Robot Maze Escape,” was published in the journal scientific advancement. The paper's first author is Yao Zhao, a postdoctoral researcher at NC State. Hao Su, associate professor of mechanical and aerospace engineering at NC State, is co-corresponding author. Additional co-authors include Yaoye Hong, a recent Ph.D. Graduated from NC State University; Yanbin Li, a postdoctoral researcher at NC State; Fangjie Qi and Haitao Qing, both Ph.D. NC State University students.
This work was supported by the National Science Foundation under grants 2005374, 2126072, 1944655, and 2026622.
NC Saint University