• 3D printing
• additive manufacturing
• bendable
• dcm
• direct ink writing
• DIW.
• dyes
• e7
• flexible
• liquid crystals
• optics
• pdms
• photoluminescence
• photonics
• polarization
• polymers
• pva
• stretchable

The aim of this Thesis is the realization and the characterization of light-emitting systems with optical properties tunable by mechanical stretching. Direct ink writing was used as printing technology and a printing methodology for stretchable elastomers (more specifically, polydimethylsiloxane) has been developed. These elastomers were used as sheath for the core-shell filaments. The core were composed of poly(vinyl alcohol) containing an emulsion of droplets of LCs (E7) doped with a light-emitting chromophore. Core-sheath structures were prepared using a core-shell printing nozzle fed by two reservoirs containing the core and the shell inks. The resulting multiphase filamentary structures were characterized by optical microscopies and by polarized photoluminescence spectroscopy. To this aim, a dedicated set-up was built for characterizing the polarization of the emission from LC/dye droplets upon stretching the printed filaments along a direction parallel to their length. An effective tuning of the polarization properties of the emitting dyes incorporated in the LC droplets and in the elastomer matrix is demonstrated. This property is relevant for the development of strain sensors and of novel optical architectures whose shape and emission properties can be tailored by external mechanical deformations.