"These soft robots demonstrate a concept called 'physical intelligence', which means that structural design and intelligent materials are the reason why soft robots can navigate in various situations, not computational intelligence," said Yin Jie, corresponding author of the paper on this work and associate professor of mechanical and aerospace engineering at North Carolina State University.
This kind of robot is made of semi transparent and elastic liquid crystal. When the ribbon soft robot is placed on a surface with a temperature of at least 55 ℃, the surface is hotter than the surrounding air. The part of the ribbon soft robot contacting the surface will shrink, while the part exposed to the air will not. This will cause rolling motion in the ribbon soft robot. The higher the surface temperature, the faster it rolls.
"Someone has made it with a smooth rod before, but this shape has a disadvantage - when it meets an object, it just rotates in place," Yin Jie said. "Our soft robots made of twisted ribbon shapes can negotiate these obstacles without any human or computer intervention."
Ribbon robots do this in two ways. First, if one end of the ribbon meets an object, the ribbon will rotate slightly to bypass the obstacle. Second, if the central part of the robot encounters an object, it will "snap". The snap is the rapid release of stored deformation energy, which makes the belt jump slightly and reposition before landing. The ribbon robot may need to buckle more than once before it can find a direction that allows it to cross obstacles, but in the end it can always find a clear way forward.
"In this sense, it is much like the robot vacuum cleaner used by many people at home," Yin Jie said. "It's just that the software robot we created draws energy from its environment and operates without any computer programming."
The first author of the paper Zhao Yao, a postdoctoral researcher at North Carolina State University, said: "The two actions that enable the robot to negotiate with obstacles, namely rotation and buckle, operate on a gradient. If an object touches the center of the belt, the most powerful buckle will occur. However, if an object touches the belt far from the center, the belt will still buckle, but the force is small. And the farther you are from the center, the less obvious the bounce will be until you reach the last five minutes of the ribbon length One, there is no bounce at all. "
The researchers conducted a number of experiments to prove that the ribbon like soft robot can navigate in various maze like environments. The researchers also proved that soft robots can work well in desert environment, indicating that they can climb and descend slopes of loose sand.
"It's interesting and looks fun, but more importantly, it provides new insights into how we can design software robots that can collect heat from the natural environment and negotiate complex unstructured environments (such as roads and harsh deserts) autonomously," Yin Jie said