New super-bouyant material: Life preserver might float a horse

Here's a story that might float your boat: Researchers in China are reporting the development of miniature super-bouyant boats that float so well that an ordinary life preserver made from the same material might support a horse without sinking.

The advance, they say, might be difficult to apply to full-size craft. However, it could lead to a new generation of aquatic robots for spy missions and other futuristic devices, the scientists add. Their study is reported in ACS Applied & Interfaces, a monthly journal.

In the new study, Qinmin Pan and Min Wang note that researchers have studied the chemistry of surfaces for years in an effort to design novel drag-reducing and fast-moving aquatic and air devices, such as boats and planes. Scientists have often turned to nature for inspiration. One source: The strider, whose highly water-repellant (superhydrophobic) legs allow this insect to literally scoot across water surfaces at high speeds. But researchers still have not found a practical way to apply this phenomenon to technology.

Pan and Wang made several miniature boats about the size of a postage stamp. They used copper mesh treated with silver nitrate and other substances to make the boats’ surfaces superhydrophobic. When compared to similar copper boats made without the novel surfaces, the water repellant boats floated more smoothly and also showed a surprisingly large loading capacity. The best performing mini-boat floated with up to two times its maximum projected loading-capacity, the scientists say. “Interestingly, the is able to keep floating even if its upper edges are below the water ,” the scientists note.

More information: "Miniature Boats with Striking Loading Capacity Fabricated from Superhydrophobic Copper Meshes" Applied Materials & Interfaces

Provided by ACS


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Citation: New super-bouyant material: Life preserver might float a horse (2009, March 11) retrieved 27 June 2019 from https://phys.org/news/2009-03-super-bouyant-material-life-horse.html
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Mar 12, 2009
It sounds to me like they are claiming that they can float something weighing more than the weight of the water displaced by the object. This might be true considering that they are relying on surface tension to do it, but this is not going to scale up to a larger size. Since horses can already float (and swim), the claim that a life preserver could float one is meaningless. An ordinary styrofoam packing peanut could float a horse.

Mar 16, 2009
It sounds to me like they are claiming that they can float something weighing more than the weight of the water displaced by the object. This might be true considering that they are relying on surface tension to do it, but this is not going to scale up to a larger size
I can't see any reason why this effect should not be scaled up, though that's a bit academic since this thing is unlikely to be robust enough for any practical use.

Firstly, any motion through the water might unbalance the effect in one direction causing instability.

Secondly, if the vessel (or life jacket) ever tips over, the hygrophopic surfaces would act the other way and sink it.



Intriguing though. If the stability problems could be overcome then there should be no practical limit to the amount of weight the platform could support, providing there was sufficient depth of water.

Mar 31, 2009
@ smiffy

Secondly, if the vessel (or life jacket) ever tips over, the hygrophopic surfaces would act the other way and sink it.


If what you're saying was true we'd have hydrophobic propulsion. You'd just get a pretty air pocket stuck to the surface and sinking would proceed as normal.

Intriguing though. If the stability problems could be overcome then there should be no practical limit to the amount of weight the platform could support, providing there was sufficient depth of water.


Based on what? If I put a coffee cup on a water strider, both would sink. The additional weight bearing capacity is due to surface tension. The ultimate load would likely be dependant on the area and radius of contact.

Apr 01, 2009
You're right. I hadn't thought the post through. I believed that the effect was something different from ordinary surface tension; due I think to the article claiming that the effect persisted with the upper edges of the boat below the surface of the water, which I took to mean that it was submerged. It's clear from the picture in their original paper that all that's taking place is buoyancy due to surface tension and a cushion of trapped air. As such, as soon as the surface skin of the water is broken the boat is bound to sink.

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