On the Behavior of Ferroelectric Liquid Droplets in the Vicinity of a Ferroelectric Solid

We analyzed the behavior of sessile ferroelectric liquid droplets in the vicinity of a pyroelectrically charged ferroelectric crystal, an experimental configuration that allows testing the recently observed coupling between the polarizations of the fluid and solid materials, in conditions of no direct contact. Results demonstrate that polarizations' coupling also exists in this configuration and has two distinct effects. Specifically, it gives rise both to an electromechanical instability of the liquid droplets consisting in the sudden ejection of interfacial fluid jets, and to a slow droplet motion toward the ferroelectric solid driven by a dielectrophoretic force. The two effects can possibly be separated, depending on the droplet size.