Tsinghua Researchers Develop Stretchy Hydrogel with Unfurlable Chains for Inflatable Robotics

Researchers at Tsinghua University in Beijing have created a new type of hydrogel that is both stretchy and maintains its original shape. This hydrogel, which is made of coiled polymer beads connected by a chain of carbon atoms, was developed by Lili Chen and her team. The researchers achieved this by inserting pearl-necklace chains into the hydrogel structure.

These chains can unfurl under strain and rewind when the strain is released. To create these chains, the researchers dried out the hydrogel so that the polymer chains were attracted to themselves rather than to water molecules. They 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.

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.