We report the results of an investigation carried on Methyl Red-doped nematic liquid crystals with the aim of studying the basic mechanism of the extraordinarily large nonlinear response recently reported. We show that the experimental data can be explained as due to light-induced modifications of the anchoring conditions leading to director reorientation on the irradiated surface, which in turn gives rise to a bulk reorientation through the cell. We have called this phenomenon SINE (Surface Induced Nonlinear Effect) to remind that it occurs "without" (= sine in latin language) a direct optical or electric torque on the director in the bulk.

We report the preparation methods and electro-optical characterization of polymer-dispersed liquid crystals with nanosized liquid crystal domains obtained by using a multifunctional monomer in a prepolymer mixture that is suitable for a fast photopolymerization process. The electric-field-induced optical phase shift has been measured using a Mach–Zender interferometer, getting values up to π/2 with an applied voltage of about 20 V/μm with no dependence on the light polarization. The high transmittance of the samples make them suitable for photonic devices and telecom applications.

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Photomobile polymer (Pmp) films are fabricated by using a cheap and fast process. The working mechanism of the Pmp-film motion under illumination is explained. Details concerning the film structure and formation are given. Two related applications regarding light-induced caterpillar-miming motion and photocontrolled electrical switches are proposed.