Experimental investigation of the stability of the floating water bridge

Abstract

When a high voltage is applied between two beakers filled with deionized water, a floating bridge of water is formed in between exceeding the length of 2 cm when the beakers are pulled apart. Currently two theories regarding the stability of the floating water bridge exist, one suggesting that the tension caused by electric field in the dielectric medium is holding the bridge and the other suggesting surface tension to be responsible for the vertical equilibrium. We construct experiments in which the electric field and the geometry of the bridge are measured and compared with predictions of theories of the floating water bridge stability. We use a numerical simulation for estimation of the electric field. Our results indicate that the two forces of dielectric and surface tensions hold the bridge against gravity simultaneously and, having the same order of magnitude, neither of the two forces are negligible. In bridges with larger diameters, the effect of dielectric tension is slightly more in the vertical equilibrium than surface tension. Results show that the stability can be explained by macroscopic forces, regardless of the microscopic changes in the water structure.

Is electrospray emission really due to columbic forces?

“…This phenomenon, first ascribed to some unknown properties of water, finally revealed to be originated just by dielectric forces. 20,21 In particular, the phenomenon is observed also in pure dielectric liquids where the deformation of the free liquid surface under an intense electric field is originated by the interaction of the electric field with the existing (both permanent and induced) dipoles while no free charge carriers can be hypothesized.…”

Light and Capillary Waves Propagation in Water Fibers

“…We fabricate optofluidic 7 – 9 fibers 10 – 13 and use them to co-host light and capillary oscillations. Our water fibers are made by water bridging 14 – 21 an optical tapered-coupler 22 to a µlensed coupler 23 . Our water-fiber diameter is at the tens-of-micron scale.…”

“…Two mechanisms participate in carrying the weight of the water fiber. The first is surface tension and the second is the electric field, also referred to as dielectric force 19 – 21 . Such water bridges were demonstrated at lengths longer than 3 centimeter 32 or with a diameter thinner than 20 nano-meters 16 .…”

“…In greater detail, similar to a vibrating guitar string, the water thread vibrates at frequencies where ρ ′ is the string mass density per unit length, L ; T is the water bridge tension and i = 1, 2, 3… is the index describing the order of the mode. The water fiber tension is affected by dielectric- 19 and surface-tensions 20 ; considering both terms, we get an equation for the tension according to reference 21 where ɛ 0 is the vacuum permittivity; D is the bridge diameter; E is the electric field along the bridge ɛ is the relative permittivity of the liquid and ɣ the surface tension. a and b here describe the ratio between electrostrictive-forces 19 , 21 and interfacial-tension 20 , 21 that are co-carrying the water bridge weight and will be fitted experimentally.…”

Reversed Currents in Charged Liquid Bridges

“…The total mass flow(20) vs. the dimensionless radius of the bridge. The parameter 8ζ/ζ 0 = 1, 5, 10, 12 from left to right.…”