Discovery of ocean insect's secret could lead to slipperier ships
The "sea skater" is one of the few insects that lives full-time in a marine environment. Scientists are now taking a closer look at how the animal repels water, with an eye towards the development of more hydrodynamic ship hulls.
In a fashion similar to that of the freshwater water strider, the sea strider is able to skitter around on thin legs that rest on the water's surface. It's also remarkably good at staying dry even when pelted by rain and waves, and at surfacing quickly after being submerged.
Working with an American colleague, researchers at Saudi Arabia's King Abdullah University of Science and Technology (KAUST) set out to get a better understanding of how the insect excels at shrugging off liquid. In order to do so, they captured two sea skater species – the open ocean-dwelling Halobates germanus and the coastal H. hayanus – which they kept in aquariums.
Utilizing techniques such as electron microscopy, the scientists discovered that the skaters' bodies were covered with hairs of different shapes and sizes. The smallest of these were shaped like golf clubs, with the heads of the clubs tightly packed together on top, and the shafts a little more widely spaced underneath.
This design keeps water from getting past the club heads, resulting in a layer of air being trapped around the insect's body. Even when the sea skaters were pushed underwater, the buoyancy of that layer caused them to pop right back to the surface. Additionally, it was observed that when grooming themselves, the insects secrete and cover their bodies with a highly water-repellant wax.
Inspired by both the hairs and the wax, the scientists are now working on a hull coating that would allow ships to more easily slide through the water, while also preventing the colonization of drag-producing organisms such as barnacles.
The research is described in a paper that was recently published in the journal Scientific Reports.