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Stanford develops a soft, expanding robot

What's New? | September 11, 2017 | By:

The vinebot robot is a tube of soft material that grows in one direction. Photo: L.A. Cicero.

Mechanical engineers at Stanford University have created a robot inspired by organisms that cover distance by growing, such as vines, fungi and nerve cells.

According to Stanford sources, the researchers’ aim is to establish a new approach to getting mobility from a mechanism. “It’s very, very different from the way that animals or people get around the world,” explained Allison Okamura, professor of mechanical engineering and senior author of their paper, published recently in Science Robotics.

The design is basically a tube of soft material folded into itself that grows in one direction when pumped with air or fluid. The design results in movement of the tip without movement of the body. Essentially a tendril that extends from an airtight cylinder, the robot could carry a camera to investigate a collapsed building, for example, instead of sending people or dogs to do reconnaissance.

“The body can be stuck to the environment or jammed between rocks, but that doesn’t stop the robot because the tip can continue to progress as new material is added to the end,” explained Elliot Hawkes, a visiting assistant professor from the University of California, Santa Barbara and lead author of the paper.

When the group put the robot through its paces, it grew through an obstacle course, traveling over flypaper and nails and up a wall of ice to deliver a sensor, enacting the delivery of a device to detect carbon dioxide exhaled by trapped survivors. The robot made the journey despite the fact that its housing had been punctured by a nail on the course. The tube was able to self-seal by remaining stationary on top of the nail.

An article from Stanford describes that in other demonstrations, the robot lifted a 100-kilogram crate, grew under a door gap that was 10 percent of its diameter and spiraled on itself to form a freestanding structure that then sent out a radio signal. The robot also maneuvered through the space above a dropped ceiling, showing its ability to navigate unknown obstacles in walls, under roads or inside pipes. Further, it pulled a cable through its body while growing above the dropped ceiling, offering a new method for routing wires in tight spaces.

A primary advantage of soft robots is that they can be safer than hard, rigid robots not only because they are soft but also because they are often lightweight—useful qualities especially when working in close contact with a person.

Future versions may also grow using liquid, which could help deliver water to people trapped in tight spaces or to put out fires in inaccessible areas. The scientists are also exploring materials like ripstop nylon and Kevlar. The team has created a 1.8 mm version and believe that small, growing robots could advance medical procedures, as well.

The research was funded by the National Science Foundation.

Video: Stanford University.

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