You searched for:
“menisci in nature”
For a tiny insect, a pond's still surface can present a challenging waterscape.
- To move from water to land, a water-walking creature may have to scale a steep, slippery slope—the curved edge where water meets leaf, rock, or floating object.
- The curvature of a liquid's surface at a boundary is a consequence of the liquid's surface tension.
- The sloped surface marking the border between wet and dry is called the meniscus.
- Very small insects typically can't climb these frictionless mountains using their normal rowing motions or running gaits.
- If they try to walk up, they slide back down.
- Instead, these insects have to rely on a novel form of propulsion that doesn't require moving their legs back and forth.
- As this water treader approaches a meniscus, its front and rear legs deform the water's surface to help it move up the slope.
- Two species of water strider, for example, have retractable claws on their front and hind legs that allow them to pull up on the water to create tiny peaks.
- At the same time, the central pair of legs presses down on the water to form dimples in the surface.
- Because the insects are small, these peaks and dimples create sufficient force to pull the insects up the slope.
- In effect, the insect creates tiny menisci with its front and rear legs.
- Because menisci are attracted to other menisci, the net effect is to pull the insect up the slope at the water's edge.
- These creatures can reach speeds as high as thirty body lengths per second.
- In technical terms, the insects take advantage of lateral capillary forces that exist between small floating objects.
- The force of attraction between body and meniscus "wall" depends on the body's buoyancy and on its distance from the wall.
- Because the insect's front legs are closer to the wall than its rear legs are, the net effect is to propel the insect forward and upward.
- The larva of the waterlily leaf beetle uses an alternative strategy to scale a slippery meniscus.
- A poor swimmer, this creature simply arches its back, creating a meniscus at each end. The insect then gets pulled up the slope to a leaf.
- In meniscus climbing, the researchers note, instead of moving its legs back and forth, an insect deforms the liquid's surface, converting muscular strain to the surface energy that powers its ascent.
- In the realm of fluid dynamics, few researchers have previously tackled situations that involve surface tension as an important component.
- The new results and related research may have important applications not only for understanding biolocomotion but also potentially in nanotechnology.
This entry is located in the following unit:
menisc-, menisco-
(page 1)