Study of the microstructure and stimuli-responsive behavior of liquid crystal elastomers

Liquid crystal elastomers (LCEs) are stimuli-responsive materials capable of undergoing large deformations due to their anisotropic molecular organization. Their mechanical behavior is influenced by mesogen alignment, crosslinking density, and mesophase type. Recent advancements in 3D printing, particularly extrusion-based deposition, have enabled precise control over LCE microstructure by leveraging shear- and elongation-induced mesogen alignment. At INMA – Universidad de Zaragoza, we have developed novel liquid crystal (LC) inks incorporating two distinct photosensitive moieties, facilitating multi-wavelength photocrosslinking. This approach enhances microstructural control and enables the fabrication of complex, stimuli-responsive architectures for soft robotics and adaptive actuators. Our study aims to characterize the mesomorphic behavior of these reactive inks and assess the impact of processing conditions on their final microstructure. Using synchrotron-based WAXS and SAXS, we will investigate: (1) the temperature-dependent phase behavior of the parent LC oligomer and its reactive inks, (2) the degree of mesogen alignment after 3D printing and photopolymerization, and (3) the stimuli-responsive actuation of LCE thin films and fibers, particularly under thermal exposure. These insights will provide a fundamental understanding of the structure–property relationships in LCEs and advance their application in, for example, soft robotics, biomedicine, and smart actuators.