Yuan and Dai padded the soles of their robots’ feet with a water-loving hydrogel.
The researchers’ added a catechol-based substance to their hydrogel so that it can glom onto surfaces as a mussel does.
One can think of the hydrogel pads on the robot’s feet as shoes.
There’s a big advantage to using electricity as the way to alter the hydrogel’s pH, says Dai.
They first engineered a “nanoinitiator,” a fancy name for a chemical that shines patterned light onto a supporting material—often a hydrogel—to cross-link into solid structures.