Ripple bugs’ frilly feet inspired a water-striding robot

2 weeks ago 16

The fanlike feet unfurl automatically, helping some bugs and bot dart crossed water

A closeup of a ripple bug connected apical of the h2o shows instrumentality structures connected its feet beneath the surface.

If you privation to locomotion connected water, it helps to person fancy feet.

A benignant of h2o strider known arsenic a ripple bug (Rhagovelia obesa) has frilly fans connected its feet. Those fans unfurl erstwhile they interaction h2o and adjacent erstwhile removed. These ripple bugs usage their feet similar oars to rapidly dart and crook atop choppy stream waters.

A caller survey shows that ripple bugs’ ft fans unfastened and adjacent automatically. No muscles are needed for that, researchers study successful the August 21 Science. Their find inspired the squad to physique a water-striding robot with frilly feet of its own.

Rice grain–sized ripple bugs boast immoderate superior agility. With assistance from their peculiar feet, they tin marque crisp turns successful conscionable 50 thousandths of a second. And they tin determination up to 120 assemblage lengths per second!

The bugs flit truthful accelerated that they look to alert alternatively than stride atop water. “If you are blinking, you miss the action,” says Víctor Ortega Jiménez. He studies carnal question astatine the University of California, Berkeley.

The fans connected ripple bugs’ feet are made of tiny, ribbon-shaped barbs. Each barbs is studded with adjacent tinier barbules.

A fan-shaped operation attached to a bug left. A closeup shows the structure, consisting of level ribbons with bladed barbules extending from each.

When dipped nether water, the stretchy barbs and barbules instrumentality out. But erstwhile pulled from the water, the attraction of h2o molecules to their fibers produces capillary forces. (Those forces effect from the h2o molecules sticking to the fibers and to 1 another.)

The unit besides pulls the barbs backmost together. It’s akin to however a paintbrush spreads erstwhile dipped into h2o and comes to a constituent erstwhile removed.

Ortega Jiménez discovered this done a elemental experiment. He attached a severed ripple bug ft to a strand of his wife’s hair. Then, helium mildly lowered the ft into a h2o droplet. In conscionable 10 thousandths of a second, it burst open.