University of Houston engineers have discovered that they can create upward fountains in water by shining laser beams on the water’s surface. Scientists attribute the finding to a phenomenon called Marangoni effect. This causes convection and explains the behavior of water when differences in surface tension exist. The Marangoni effect was first described in the 1860’s, and is still having its way with science.
Sprinkle a bunch of pepper into a bowl of water. Then squeeze one drop of liquid detergent into the middle of the same bowl. Then watch as the pepper disburses and scattering quickly to the sides of the bowl. This experiment illustrates the Marangoni effect. It appears in many applications of fluid dynamics.
Marangoni effect’s laser-induced liquid fountains have potential to impact applications involving liquids or soft matters like lithography and 3-D printing. It also includes heat transfer and mass transport, dynamic grating and spatial light modulation and microfluidics and adaptive optics, crystal growth and alloy welding.
The successful simulation of inward surface depression in a shallow liquid inspired scientists to increase the depth of ferrofluid in the current simulation. Ferrofluid is known as “magic” liquid and is famous for its astonishing surface spikes generated by a magnet. Scientists used a low-power continuous-wave laser beam and created a non-uniform surface temperature field to induce the Marangoni effect.
Scientists tried to understand the distinct deformations between deep and shallow liquids and they varied the liquid layer thickness while keeping the laser beam the same. The laser fountains and the depth-dependent transition from surface indentation to laser fountain is not there in literature. As they are not expected by any existing theory.