Ancoragem e geometria de gotas sésseis de cristais líquidos: uma análise por simulação

Abstract

Sessile liquid crystal droplets (CLs) exhibit complex structures dictated by the interplay between elasticity, surface anchorage, and intrinsic chirality. However, understanding the combined influence of drop geometry (contact angle, 𝜃𝜃), interfacial anchorage conditions, and chirality of CLs remains a challenge. We investigated, via computer simulations based on the Landau-de Gennes theory (Marlics), the equilibrium structure and energy of nematic and cholesteric CL sessile droplets on substrates. We systematically varied both θ and six anchorage combinations (homeotropic/planar). The analysis reveals that anchoring compatibility dominates energy stability: symmetrical planar configurations exhibit low energy, contrasting with the high frustration and energy of symmetrical homeotropic anchoring. Mixed anchorages result in intermediate, often non-monotonic energies with θ. The results showed that the contact angle critically modulates the energy competition and induces significant structural transitions, mapping the energetic and structural behavior of confined LCs. These results establish a conceptual physical model of the system's energetic behavior, in which geometry and anchoring can be adjusted to generate specific topological structures, with applications in optical microdevices and sensors.