An untethered isoperimetric soft robot
The simplest version of this squishy robot 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; 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.