The resulting robotic prototype contained ten spines and five high aspect ratio tube feet organized in a symmetrical penta-radial geometry. The rigid spines were fabricated with an integrated ball joint structure that exhibited a range of motion comparable to that observed in living urchins. The high aspect ratio tube feet, on the other hand, were designed as an extensible asymmetric bellow cylinder with an embedded neodymium magnet in the tip to enable locomotion on ferrous surfaces using a reach, attach, retract, and release sequence.