Top view of a liquid crystal drop on the pyroelectric substrate, after heating.

Very interesting effects can be observed when maneuvering liquid crystal droplets onto functionalized polar dielectric crystal surfaces. It has been discovered that the pyroelectric effect is able to drive a reversible fragmentation process in liquid crystal drops, starting from nanoliter drops and obtaining pico/femtoliter droplets. These small droplets are patterned according to the geometry of the substrate and aligned along the electric field lines.

This novel approach for manipulating liquid crystals by a thermal stimulus could be suitable for applications such as spatial modulation of wettability (i.e. wettability patterning), or, in principle, a dynamical optical element able to switch from a diffuser (fragmentation state) to a microlens array (coalescence state). The coalescence effect could be helped by an appropriate micropatterning of the substrate allowing for microlenses in fixed locations.