Capillarity and dielectrophoresis of liquid deuterium

The ponderomotive force, exerted upon all dielectric liquids by a non-uniform electric field, can be used for the remote, voltage-controlled manipulation of 10 to 100μL volumes of cryogenic liquids. This liquid dielectrophoretic (DEP) effect, imposed by specially designed electrodes, combines with capillarity to influence the hydrostatic equilibria of liquid deuterium. A simple, one-dimensional model accurately predicts the measured meniscus rise of D2 against gravity for sufficiently wide, parallel electrodes. For narrow electrodes, where the sidewalls influence the equilibrium, a finite element solution using the Surface Evolver software correctly describes the shape of the meniscus. A bifurcation phenomenon previously observed for room temperature dielectrics is also observed in liquid deuterium. Cryo-DEP actuation has potential applications ranging from metering precise volumes of liquid deuterium for laser target fuelling to manipulation of liquid nitrogen for cryo-preservation of biological samples. (Some figures in this article are in colour only in the electronic version)