By combining the exquisite control of microfluidic double emulsion production with the self-assembly of liquid crystals, spherical shells with peculiar optical properties can be produced at high throughput and excellent reproducibility. In this webinar by the Experimental Soft Matter Physics (ESMP) group at the University of Luxembourg in collaboration with Fluigent, we will demonstrate, first, that the liquid crystal shells form a rich and intriguing platform for innovative photonics research. Second, we show that polymerization of the shells into solid spheres turns them into retroreflectors that give omnidirectional selective reflection of circularly polarized light in a wavelength window that can be tuned from the near infrared (near-IR), throughout the visible spectrum, to the near ultraviolet (near-UV). These selective retroreflectors are incredibly useful, opening a plethora of application opportunities over a vast range of societally and commercially relevant fields, from anti-counterfeiting to robot guidance and Augmented Reality support to improved supply chain transparency and traceability.
• Introduction to cholesteric liquid crystal shells and why they are so interesting, from a fundamental science point of view and from an applied point of view (10 minutes; ESMP).
• Description of how cholesteric spherical retroreflectors are made, from microfluidic shell production to polymerization and washing (15 minutes; ESMP).
• Introduction to the Raydrop platform for making multiple emulsions with high degree of control and excellent reproducibility at high throughput.
• Assessment of the potential of the Raydrop platform and its advantages compared to other solutions for multiple emulsion production, from the point of view of making cholesteric liquid crystal shells.
Special host: Jan lagerwall Professor in Experimental polymer physics at the Experimental Soft Matter Physics (ESMP) group at the University of Luxembourg.