Engineers at MIT have fabricated transparent, hydrogel robots which can catch and release live goldfish without harming them.

The latest and greatest innovation from the boffins at MIT are tiny hydrogel robots with a “claw” that can grab and release objects. The principle is the same as those arcade grabber machines where you try (and fail) to win a stuffed toy.

Each robot derives power by pumping water in and out of it. They can perform impressive tasks like catching and releasing a live fish, or even kicking a ball underwater.

Hydrogel, meanwhile, is a tough and rubbery material whose composition is mostly water. That means the robots have a similar acoustic and visual property to water, which has the added benefit of making them virtually invisible when submerged.

These hydrogel robots are made with 3D printing and laser cutting. Once built, researchers bond the robots to small, rubbery tubes which connect them to external pumps.

Hydrogel Robots Could be Used in Surgery

The group was led by associate professor of mechanical engineering and civil and environmental engineering at MIT, Xuanhe Zhao. He explains:

“Hydrogels are soft, wet, biocompatible, and can form more friendly interfaces with human organs. We are actively collaborating with medical groups to translate this system into soft manipulators such as hydrogel ‘hands,’ which could potentially apply more gentle manipulations to tissues and organs in surgical operations.”

Zhao’s group has been working on developing the perfect recipe for hydrogels for five years. They’ve mixed solutions of polymers with water and invented techniques to develop tough, stretchy materials.

Impressively, the team found that the hydrogel robot designs could withstand repeated use of up to 1,000 cycles without tearing or rupturing.

As you can see in the video above, they created a hand-like robotic gripper and submerged it in a water tank with a goldfish. Amazingly, they were able to catch the fish without harming it.

“(The robot) is almost transparent, very hard to see,” Zhao says. “When you release the fish, it’s quite happy because (the robot]) is soft and doesn’t damage the fish. Imagine a hard robotic hand would probably squash the fish.”

As well as catching fish, the researchers believe the hydrogels could be useful when creating soft robotics. Zhao points out that in a biomedical setting, hydrogel is naturally safer than other materials.

Interested in learning more? The full research paper is available in the journal Nature Communications.

Source: MIT News