Electric field induced interfacial instability in a ferroelectric nematic liquid crystal

The investigation of the external magnetic or electric fields induced surface instabilities in fluids are not only interesting and spectacular but also a widely used part of physics, like the electric field induced Rayleigh instability which is the basic mechanism of electrospinning. After the recent discovery of polar nematic materials, which have a ferroelectric nematic phase, an obvious question arises: Can a new type of electric field driven surface instability be observed in these materials? We investigated the response of a ferroelectric nematic liquid crystal to electric fields in various geometries. In our experiments, we observed pattern formation as a consequence of an electric field induced surface instability. We characterize the effect and provide a model to explain the basic mechanism of the pattern formation observed in ferroelectric nematic droplets with free surface exposed to electric fields.