Reconfigurable Photonic Capsules Containing Cholesteric Liquid Crystals with Planar Alignment

Abstract

Cholesteric liquid crystals (CLCs) reflect selected wavelengths of light owing to their periodic helical structures. The encapsulation of CLCs leads to photonic devices that can be easily processed and might be used as stand-alone microsensors. However, when CLCs are enclosed by polymeric membranes, they usually lose their planar alignment, leading to a deterioration of the optical performance. A microfluidics approach was employed to integrate an ultrathin alignment layer into microcapsules to separate the CLC core and the elastomeric solid membrane using triple-emulsion drops as the templates. The thinness of the alignment layer provides high lubrication resistance, preserving the layer integrity during elastic deformation of the membrane. The CLCs in the microcapsules can thus maintain their planar alignment, rendering the shape and optical properties highly reconfigurable.

Polymer and Mesoporous Silica Microspheres with Chiral Nematic Order from Cellulose Nanocrystals

“…[1] Furthermore,the structures and topologies of these colloidal particles are scientifically very interesting. [3] Aßhoff et al recently showed that superstructures of photoresponsive chiral nematic microspheres prepared in am icrofluidic device are promising for chiroptical switches and distributors. [3] Aßhoff et al recently showed that superstructures of photoresponsive chiral nematic microspheres prepared in am icrofluidic device are promising for chiroptical switches and distributors.…”

Formation of Photo-Responsive Liquid Crystalline Emulsion by Using Microfluidics Device

“…It would be possible to utilize the photo-control of the LC double emulsion for the purpose of active matter, in which it is expected that the force and the direction of the long-ranged molecular interaction should be controlled. To generate a larger force, a LC polymer would be a promising material, which can induce a macroscopic motion such as bending for a film [15]. Furthermore, this study would give more information on the dynamics of the defect behavior of LCs, which would be relevant to various biological phenomena on a cell membrane.…”

“…Moreover, the color control of a cholesteric liquid crystal droplet with photo-responsive chiral dopant was reported, and the color ranged from blue to red [12,13], and also it was demonstrated for the lasing application [14]. By encapsulating this LC droplet with a polymer core, the coloring particle was successfully developed [15].…”

Elucidating the fine details of cholesteric liquid crystal shell reflection patterns

“…The shell geometry also has the advantage that polymer stabilisation of the CLC works very well, making the spheres mechanically robust with minimum negative effect on the optical properties. Another possibility of ensuring robustness is to encapsulate a CLC droplet inside a transparent elastomer shell [29,30].…”