Boat Moves Without an Engine Or Sails

coondoggie writes "Researchers say technology they have developed would let boats or small aquatic robots glide through the water without the need for an engine, sails or paddles. A University of Pittsburgh research team has designed a propulsion system that uses the natural surface tension that is present on the water's surface and an electric pulse to move the boat or robot, researchers said. The Pitt system has no moving parts and the low-energy electrode that emits the pulse could be powered by batteries, radio waves, or solar power, researchers said in a statement."

Comments

primary school chemistry, anyone?

[arth1]

We made boats that moved by weakening the surface tension back in primary school.
Stick a piece of soap on the stern of a paper "boat", and it is propelled forward.

However, I can't see how the surface tension would be strong enough to drive a full sized boat at any speed. At best you're talking about a few millimetres elevation difference between the bow and stern, if the water is very salty and there's absolutely no wind or currents causing waves.

little slow?

[Tree131]

So, at 14.4 meters/h, this is only useful for bodies of still water.
Looking forward to improvements in speed, 'cause I think ocean currents move faster than that.

Re:little slow?

[eggnoglatte]

Right. And speeding up horse carriages is just a matter of how many horses you use. Not.

The fundamental power source here is gravity, by using the difference in elevation of the water surface with low surface tension at the back of the boat and normal surface tension in front. That elevation difference is tiny, and the power it can provide is therefore fundamentally limited.

Re:Calm water

[TapeCutter]

Good question. Many moons ago I worked the fishing boats in Bass Straight. Can it drive a semi-submerged fishing trawler 30 feet up at about a 15-20deg incline, or would gravity drag it backwards?

Re:Is it the Red October?

[pato101]

If I recall correctly, surface tension forces only count to steady state (low velocity motions). Thus, this thing (the story one) only will work at moderate speeds (look at the video: there are no waves in the surface because of the low velocity motion, also means high efficiency). What you propose would generate strong motions, which would kill the tension surface forces.

Re:Calm water

[MightyYar]

No, no, feed them. It's fun to watch the racists all going ape-shit right now.