There is no reason for soft robots to entirely replace traditional robots, but there are many situations in which they’d be preferable. Just one example is within environments where robots need to work alongside humans, because soft robots are much less likely to cause injury. The major downside of most soft robots is how the flexible bladders are inflated or deflated in order to facilitate locomotion. That’s usually done with pneumatic or hydraulic pumps, which tend to be slow and noisy. In contrast, this soft robot developed at Stanford University is able to transform itself using simple rollers.
This robot certainly looks unique, as it’s made up of many bright red segments and a mechanical contraption at each vertex connecting those segments. Those red segments are actually airtight, flexible fabric tubes that have been filled with enough air to give them structure — similar to the tube man that sits in front of that car dealership you pass on the way to work. The tubes are sealed so that air doesn’t leak, and the internal pressure is high enough to keep them rigid while still allowing for some give. The mechanical contraptions at each vertex are what bring the robot to life.
Those contraptions are motorized rollers, which the red tubes feed through. By spinning the motors on the rollers, the length of each red segment can be changed. Imagine a triangle with each corner being a roller and the segments between being the inflated tubes. Spinning the rollers can cause the triangle to change from isosceles, to a right triangle, to an equilateral triangle. Put a few of those triangles together and you’ve got a three dimensional shape that can be modified on the fly, giving the robot the ability to roll along or adjust itself to suit specific jobs. Because no air pumps are required, this robot’s morphing ability can happen far more quickly than with most other soft robots that we see. So far, the team has just been working on proving the concept, and they plan to continue experimenting to find out what useful geometry they can come up with.