Stretchy yet Shape-Shifting: Tsinghua University’s Hydrogel Revolutionizes Soft Robotics

In Beijing, Lili Chen and her team at Tsinghua University have made a groundbreaking discovery in the field of hydrogels. They have developed a new type of hydrogel that is both stretchy and maintains its original shape. This was achieved by inserting pearl-necklace chains into the hydrogel structure, made of coiled polymer beads connected by a chain of carbon atoms.

These chains can unfurl under strain and rewind when the strain is released. The researchers found that their hydrogel could stretch to nearly 5 meters before quickly returning to its original length. A 2-centimeter-wide disc of the hydrogel could increase 100 times in area before returning to its original size.

This new hydrogel has many potential applications, including use in robotic grippers or tendons. Hydrogels are known for their stretchiness, but they often do not return to their original shape when overstretched. This new hydrogel is able to maintain its shape due to the pearl-necklace chains that allow it to rewind under strain and return to its original form when released.

The researchers also created inflatable robotic grippers from the hydrogel, designed to handle delicate objects like strawberries. These grippers were extremely damage resistant, able to withstand being stood on or pierced with a needle. Zehuan Huang at Peking University praised the work, stating that this hydrogel represents a major breakthrough in high-performance polymeric materials and will inspire interest in using hyper-elastic gels in soft robotics.