Soft Robot Grows, Shrinks, Walks on Water

A squishy robot that can change its body like a shape-shifter sounds like science fiction, but researchers just made it real.

Scientists at the Southern University of Science and Technology in Shenzhen, China, have created GrowHR, a soft humanoid robot that can grow and shrink on command. Unlike traditional robots that are rigid and dangerous when they fall, this one is lightweight, flexible, and safe enough to bump into people without causing injury.

The secret lies in how the team borrowed from nature. Human bones grow strong and light by using nutrients from the body, so the researchers built robot "bones" from soft, airtight chambers wrapped in tough fabric.

When they pump air into these chambers, the robot's limbs stretch to over three times their original length. Release the air, and it shrinks to just 36% of its height and 61% of its width, allowing it to slip under furniture or through narrow gaps.

The robot weighs only 4.5 kilograms, making it light enough to float and walk across water using special fins. Add small fans, and it can fly too. In one test, a drone carried the robot 5.5 kilometers through the air before landing successfully.

The design solves one of robotics' biggest problems: safety. Traditional humanoid robots are heavy and stiff, posing risks if they topple or collide with people. GrowHR's soft, elastic body absorbs impacts like a cushion, making it safe for homes, hospitals, and crowded spaces.

To keep the growable limbs stable while walking and carrying loads, the team connected them with tension cables, small motors, and carbon-fiber guides. This lets the robot switch seamlessly between walking upright and crawling low to the ground.

Why This Inspires

This breakthrough opens doors for robots that can truly work alongside humans. Imagine rescue robots that squeeze through earthquake rubble, home assistants that shrink to clean under beds, or water-rescue bots that walk across lakes to reach people in trouble.

The research, published in Science Advances, shows how looking to nature can solve modern engineering challenges. By studying something as familiar as bone growth, scientists created technology that seemed impossible just years ago.

GrowHR is still a lab prototype with some kinks to work out. The waterproof skin slightly limits its swimming ability, and the team continues refining the design for real-world use.

But the researchers see enormous potential for robots that adapt to dynamic, unpredictable environments. As technology gets softer and smarter, the line between rigid machines and flexible helpers continues to blur in the most hopeful ways.