Why use water surface tension for propulsion when the wind is more efficient?
Here’s a great scoop by Ben Meakin of Practical Boat Owner, who reports research into propulsion by water surface tension by the Mechanical Engineering and Materials Science department of the University of Pittsburgh.
As Ben reveals, they have managed to make a tiny 2cm model that was propelled by creating ‘asymmetric force configurations’ on the surface of the water. By mimicking the bending movements some insects use to change their relationship to the meniscus, the direction of the surface tension is changed to propel water-borne insects forward.
This, says Assistant Professor Sung Kwon Cho, demonstrates the capability of water tension to steer and manoeuvre floating objects, which PBO helpfully illustrates with what looks like a photo of a pair of copulating Mayfly. What interests me is whether water tension could be of any use, as is suggested by the academics, to ‘traverse the world’s oceans’.
1. Don’t you need calm water for this?
2. Wouldn’t a more logical way of using water alone for propulsion offshore be a wave-driven vessel such as the one navigated across the Pacific last year by Japanese solo sailor Kenichi Horie ?
3. How could either of these be more efficient or greener than using the wind – 50 days around the world?
I’m struggling to think of any purpose afloat that would be better served by surface tension propulsion than the wind. Anyone got any suggestions?