(via Vapour-driven Marangoni propulsion: continuous, prolonged and tunable motion)
Who doesn't love learning physics? Here is a tweaked version of a grade school experiment.
In a project being conducted at Aalto University in Finland, Robin Ras, from the applied physics department, and his team are collaborating with a team in Israel to develop a super efficient boat that self-propels using the Marangoni propulsion.
The Marangoni effect happens when a surfactant, or a compound that lowers the surface tension of a liquid, creates a difference in surface tension and a resultant force that propels the boat.
The boat is made of lightweight nanocellulose aerogel that is gas permeable. The boat is successfully propelled by organic ethanol in water and by pentane in paraffin oil. The fuel is stored in a small compartment on the boat. The fuel vapor permeates through the aerogel membrane into the liquid it floats on and then spontaneously evaporates out of the fluid to maintain constant velocity. The researchers also found they can vary the velocity of the boat by using different fuels that produce different vapor pressures.
The boat is super fuel-efficient needing just drops of fuel. Using 25 micro liters, the boat cruised for over 54 minutes travelling at a speed of 2cm/s.
Currently, the boat is not maneuverable but its geometry steers it in a circular path. No applications have been proposed but the experimental results are a phenomenal step for soft matter research. The team stated that this method could be applied to even tinier vessels.
This boat may not have any immediate uses, but it sure makes for a good physics lesson.
Cabe
