Probing a Microviscosity Change at the Nematic-Isotropic Liquid Crystal Phase Transition by a Ratiometric Flapping Fluorophore

Understanding the microviscosity of soft condensed matter is important to clarify the mechanisms of chemical, physical or biological events occurring at the nanoscale. Here, we report that flapping fluorophores (FLAP)...

Probing a Local Viscosity Change at the Nematic-Isotropic Liquid Crystal Phase Transition by a Ratiometric Flapping Fluorophore

Local viscosity change in the thermal phase transition of a nematic liquid crystal, 5CB, has been analyzed by doping fluorescent viscosity probes, flapping fluorophores (FLAP) as well as a molecular rotor BODIPY-C12. As a result, only flapping anthraceneimide has successfully monitored a small viscosity change (corresponding to a few cP (centipoise) change in shear viscosity around 25 cP) in the nematic-to-isotropic phase transition by ratiometric spectroscopy. In addition, analysis of fluorescence anisotropy indicates that the emissive species (planarized flapping anthraceneimides) are aligned parallel to the director of 5CB in the nematic phase.

A multifunctional shape-morphing elastomer with liquid metal inclusions

Natural soft tissue achieves a rich variety of functionality through a hierarchy of molecular, microscale, and mesoscale structures and ordering. Inspired by such architectures, we introduce a soft, multifunctional composite capable of a unique combination of sensing, mechanically robust electronic connectivity, and active shape morphing. The material is composed of a compliant and deformable liquid crystal elastomer (LCE) matrix that can achieve macroscopic shape change through a liquid crystal phase transition. The matrix is dispersed with liquid metal (LM) microparticles that are used to tailor the thermal and electrical conductivity of the LCE without detrimentally altering its mechanical or shape-morphing properties. Demonstrations of this composite for sensing, actuation, circuitry, and soft robot locomotion suggest the potential for versatile, tissue-like multifunctionality.

Topological defects and geometric memory across the nematic–smectic A liquid crystal phase transition

We study transformations of self-organised defect arrays at the nematic–smectic A liquid crystal phase transition, and show that these defect configurations are correlated, or “remembered”, across the phase transition.

Ferroelectric metallomesogens composed of achiral spin crossover molecules

We report for the first time ferroelectricity induced by spin transition associated with a crystal – liquid crystal phase transition in achiral spin crossover molecules.