This story appears in the May 2017 issue of National Geographic magazine.

Banish your preconceptions of robots as stiff, herky-jerky metal machines. An “octobot” less than three inches wide is changing the robotics landscape.

The octobot is the world’s first completely soft, autonomous, and untethered robot. It is free of wires, batteries, and any hard material—like its namesake, the octopus, which has no internal skeleton.

A Harvard University research team led by engineering professors Robert Wood and Jennifer Lewis tried more than 300 designs before they came up with one that worked. And now the octobot could revolutionize the use of robots. Traditional robots are “fantastic for what they do in terms of automation, but they’re not geared toward human interaction,” Wood says. Soft robots provide a safer solution: “If they run into something, it’d be like bumping into a basketball. It won’t hurt you.”

Before the octobot, soft robots were either hybrids—pliable exteriors with hard guts of batteries or wires—or soft models tethered to an external cord. The octobot eliminates these restrictions. It moves by pneumatic power: An internal circuit triggers chemical reactions, turning its liquid hydrogen peroxide fuel into a gas, which inflates the robot’s limbs and allows them to move. The whole assembly is created from silicone using a 3-D printer.

The octobot is currently a prototype, but its writhing arms prove that the technology works. The goal, says Wood, is to find viable applications, such as in health care. Soft robots could be made from biocompatible and biodegradable materials—and, he says, might even be formed into capsules to be swallowed for more effective and less invasive endoscopies.