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."

Can't MHD already do this?

[bistromath007]

Sure, MHD drives that I know of are slow and run on superconductors, but that was back in the early 90's, they should be able to gin up something better by now.

Calm water

[Joebert]

Can this really work outside of a lab, where the water surface isn't like glass ?

Never very practical

[Anonymous Coward]

I few years back a Japanese boat was tested using a magnetic drive. It used the fact water moves in one direction in a magnetic field, air does the same thing and you can even make a fan with no moving parts that way. The problem was it only was able to hit a couple of miles an hours inspite of the massive magnetic field. There was even talk before that of high speed boats using the technique. It's more of a science curiosity than a practical means of propulsion.

Re:Is it the Red October?

[Arker]

Err scratch that. Teach me to post in this heat.

Apparently it relies on surface tension and would not, therefore, be very useful on a submersible vehicle. :((

Might be nice for whale-watching and the like, at least. Engine noise scares off a lot of creatures that would otherwise be observable. But sailing ships are already quiet enough for that, so I'm not sure I see a real viable purpose for it at the moment.

Still, just as pure research, it's pretty cool.

Re:Is it the Red October?

[w0mprat]

It would not be difficult to generate a surface tension when deep under water, you just need bubbles, thus it could possibly be applied to a submersible. The mechanics of how that might work I'm not to sure about, perhaps moving bubbles along a surface by changing electrical potential, thus moving some water with them for thrust.

Re:Calm water

[pato101]

AFAIK, no: the tension surface forces are only strong when the surface is in almost steady state.
I've forgotten most of these issues, but I recall solving tension surface problems, and there was a condition which meant almost steady state. The idea is that when the surface is in motion, convection and pressure terms become dominant over surface tension (the pressure gradients generated by convection are much larger than the pressure gradient due to surface tension).

Re:Calm water

[WindBourne]

I grew up on a lake as a kid. I used to watches similar bugs (and others). The answer is that they CAN go on waves as long as they are not breaking up. Once turbulent (white caps), then I never saw them. Though to be honest, it is possible that the wind simple blew them into shore and I did not notice. Typically, at high winds, I was more interested in sailing rather than swimming or water skiing.

Incongruities

[acidreverb]

Did anyone else find the copper sheet at the bottom of the water odd? Is that necessary to the device's operation? Would you always have to have a static component for something like this to work?

Also, the "boat" didn't seem to have a power source, the electrodes appeared to be attached only to each other.

The article seems rather bereft of information other than comparing the electrodes to a beetle larva. Does anyone understand how this device works? Outside of vague notions of something to do with surface tension that is.

Re:Is it the Red October?

[pixelpusher220]

Actually it would be useful on a submersible vehicle.

Much like a paddle doesn't work well underwater, since you can't pull it out of the water to move it forward, this would have the same problems. But what if you have enclosed spaces of air under water like under a dome shaped object. Now you have surface water....under water. The weight of the craft keeps it underwater, and yet you have an air space by which to use your paddle, or in this case the electric charges to affect surface tension.

It seems like this would be a real bonus to release a bunch of autonomous drones to go out and study something in deep water, let them travel around slowly doing their observations, no human intervention needed.