Professor Feng Wei's team at Tianjin University has developed a single-material soft robot with untethered motion ability using 4D printing without any other processing procedures.

The robot is able to roll stably and powerfully, and its speed and direction can be adjusted by changing its shape and size. Moreover, the intelligent responsive behavior of the robot constitutes machine perception based on artificial intelligence. The research results were published in the top Cell Press journal Matter.

3D printing can transform design ideas into complex parts automatically and accurately based on digital models, while 4D printed structures are analog autonomous objects created by combining 3D printing with new engineered smart materials that evolve over time without the need for computerized power at the device, according to a review by ABB.

Prof. Feng's team accurately processed liquid crystal elastomers through 4D printing and built an intelligent soft robot with perception and adaptability. "A soft robot can adapt to different unstructured environments and interact with humans more safely," Prof. Feng said.

Through perception of heat, the autonomous robot can independently change its shape and adjust its speed and direction when moving. Its ability to autonomously control its direction is possible through tactile perception similar to an insect with a pair of antennae, which helps it detect obstacles ahead and make corresponding responses, like climbing over obstacles or turning back, in reference to the height of the obstacles.

Demonstration of intelligent tactile perception process

"When the robot is placed on an inclined heating plate at a certain angle, it can roll up autonomously," Prof. Feng noted, "The whole driving process of this soft robot is automatic without changing environmental factors. The robot can complete tasks without human control."

The robot can carry a load that is 40 times its own weight and has broad application prospects in cargo transportation and intelligent exploration under extreme high temperature conditions.