The dynamic effect of an electric
field on dielectric liquids is
called liquid dielectrophoresis. It is widely used in several industrial
and scientific applications, including inkjet printing, microfabrication,
and optical devices. Numerical simulations of liquid-dielectrophoresis
are necessary to understand the fundamental physics of the phenomenon,
but also to explore situations that might be difficult or expensive
to implement experimentally. However, such modeling is challenging,
as one needs to solve the electrostatic and fluid dynamics equations
simultaneously. Here, we formulate a new lattice–Boltzmann
method capable of modeling the dynamics of immiscible dielectric fluids
coupled with electric fields within a single framework, thus eliminating
the need of using separate algorithms to solve the electrostatic and
fluid dynamics equations. We validate the numerical method by comparing
it with analytical solutions and previously reported experimental
results. Beyond the benchmarking of the method, we study the spreading
of a droplet using a dielectrowetting setup and quantify the mechanism
driving the variation of the apparent contact angle of the droplet
with the applied voltage. Our method provides a useful tool to study
liquid-dielectrophoresis and can be used to model dielectric fluids
in general, such as liquid–liquid and liquid–gas systems.