Engineering news
The researchers at Stanford University in California borrowed features from traditional robotics to create the soft robot, which they say is safe to interact with yet able to move around and change shape.
“A significant limitation of most soft robots is that they have to be attached to a bulky air compressor or plugged into a wall, which prevents them from moving,” said mechanical engineer Nathan Usevitch, a graduate student at Stanford. “So, we wondered: What if we kept the same amount of air within the robot all the time?”
From that starting point, the team ended with a human-scale soft robot that can change its shape, allowing it to grab and handle objects, and roll in controllable directions.
The simplest version is an inflated tube that runs through three small machines that pinch it into a triangle shape. One machine holds the two ends of the tube together while the other two drive along the tube, changing the overall shape of the robot by moving its corners. The researchers call it an “isoperimetric robot” because although the shape changes dramatically, the total length of the edges – and the amount of air inside – remains the same.
To make a more complex version of the robot, the researchers attach several of the triangles together. By co-ordinating the movements of the different motors, they can control the robot for different tasks. The technique makes it an “adaptable and robust system”, said Mac Schwager, assistant professor of aeronautics and astronautics and co-author of the paper.
A video posted by Stanford shows the robot rolling, grasping objects and moving around people. Its shape-changing and moving ability is currently fairly slow, with the video frequently sped up to reveal complete actions.
The researchers said the ‘safe-but-sturdy’ softness of the device could make it useful in homes or workplaces, where traditional robots might cause injury. Malleable robots are also tools for disaster response.
There could also be exciting applications for an isoperimetric robot in space. “This robot could be really useful for space exploration – especially because it can be transported in a small package and then operates untethered after it inflates,” said mechanical engineer Zachary Hammond, co-lead author of the paper with Usevitch. “On another planet, it could use its shape-changing ability to traverse complicated environments, squeezing through tight spaces and spreading over obstacles.”
The team is experimenting with different shapes and are considering putting the device in water to see if it can swim.
The research was published in Science Robotics.
Want the best engineering stories delivered straight to your inbox? The Professional Engineering newsletter gives you vital updates on the most cutting-edge engineering and exciting new job opportunities. To sign up, click here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.