This MIT Hydrogel Is 90 Percent Water and Puts Super Glue to Shame

Researchers at MIT have developed a hydrogel that's 90 percent water, as strong as industrial glue, and might mean big things for the future of robotics. 

by Sam Blum

Researchers at the Massachusetts Institute of Technology took inspiration from tiny sea-dwelling barnacles to develop a glue-like substance that might have a profound effect on the field of robotics in coming years.

Just as barnacles glue themselves to the hulls of ships with suction that’s seemingly immovable, researchers at MIT say they have developed a hydrogel that contains a similar degree of durability and stickiness. What’s more, the gel is 90 percent water, and might catalyze some strong advancements in the field of robotics in the coming years.

The hydrogel, which has a gooey consistency and a mostly clear, transparent color, can adhere to a myriad of surfaces such as glass, silicon, and titanium. According to researches, it mirrors the strength that tendon and cartilage has on bone.

Detailed in a paper published today in the journal Nature Materials, are the methods researchers used to develop the ultra-evasive substance. In a video published today by MIT, a series of tests show that the hydrogel’s strength is on par with heavy-duty industrial glue.

Throughout the above video, uploaded to YouTube today, researchers conduct some tests, including smashing a silicon wafer which is coated in the hydrogel.

Due to the chemical bonds of polymer networks, which are similar to those found in glue, the wafer doesn’t break:

The hydrogel is also conductive. Researches hooked the gel up to two different electrodes and found it could provide the conduit necessary to power an LED light bulb, even when stretched up to 4.5 times its original size.

Different hydrogels are already used in a variety of fields, and are often used to repair damaged tissue in surgical procedures, but Xuanhe Zhao, lead researcher on the paper and a professor in MIT’s Department of Mechanical Engineering, is excited about his particular group’s hydrogel, and says it may find itself primed for different uses in robotics.

“Hydrogels can act as actuators,” Zhao says. “Instead of using conventional hinges, you can use this soft material with strong bonding to rigid materials, and it can give a robot many more degrees of freedom.”

In that sense, Zhao likens different mechanical robot hinges to human joints which swivel, bend, and move. Not unlike the cartilage that affords human beings momentum, MIT’s hydrogel will buffet the movements of our robot counterparts.

Zhao’s study should allay any thought of the gel being warn down by the friction of machine movements. It’s incredibly strong, and “is on the same level of toughness for tendon-bone and cartilage-bone interfaces,” according to Zhao.

Under a more traditional framework however, the hydrogel would provide “soft, wet, yet robust coatings and matrices for biomedical devices in close contact with human body,” such as catheters and biomedical devices implanted in the human body.