Light-activated Janus microswimmers in a thermotropic liquid crystal

• DOI: 10.48550/arxiv.2312.12866
• Publication Date: 2023-01-01
• Authors: Antonio Tavera-Vá...; Andrés Córdoba; Sam Rubin; Juan Pablo
• Keywords: Thermotropic crystal

The development of synthetic microswimmers has advanced our understanding the fundamental self-propelled mechanisms living systems. However, there are scarce studies at microscale within highly structured anisotropic media, such as bacteria or cellular receptors that swim in concentrated solutions filamentous proteins lipids with viscoelastic properties. Synthetic liquid crystals (LCs) have potential to serve biomimetic surrogates study structure and dynamics Nevertheless, on thermotropic LCs mainly focused electro magneto-phoretic effects, a few others diffusiophoresis light-driven distortions LC nematic director. To best knowledge, here we report self-thermophoretic experiments for first time. Our system consists 2D confined Janus particles 5CB homeotropic anchoring particle cell surfaces. include conductive titanium coating that, upon exposure an LED source, is heated induces local steady nematic-isotropic phase transition, leading self-propulsion orthogonally trajectories were tracked different intensities applied light. A model developed describe mean-squared displacement suspended LC. assumes feels continuum viscosity bulk phase. Moreover, viscoelasticity also considered. describes experimental data well, fitting parameter related magnitude swimming force increases intensity approach suggests possibility utilizing microrheological measurements LCs.