For the first time we were able to implant a laser into a single human cell. Furthermore, we have demonstrated that the fat cells in our body already contain lasers, which need only to be activated. In both cases the lasers are in the form of small solid spheres or lipid droplets. Deformation of the droplets enables accurate measurements of the forces inside the cells. The emission of each laser within a cell can also be used as a barcode with enough unique combinations to tag all the cells in the human body.
COBISS.SI-ID: 28881191
We demonstrate full control over the creation, manipulation and analysis of topological charges that are pinned to a microfibre in a nematic liquid crystal. Oppositely charged pairs are created through the Kibble–Zurek mechanism by applying a laser-induced local temperature quench in the presence of symmetry-breaking boundaries. The pairs are long-lived, oppositely charged rings or points that either attract and annihilate, or form a long-lived, charge-neutral loop made of two segments with a fractional topological charge. Experimental results were described using numerical modelling in the frame of Landau-de Gennes theory.
COBISS.SI-ID: 2786916
With the use of two-photon laser lithography we create hollow Koch fractal shaped polymer prisms which we disperse in nematic liquid crystal. The formation of geometry-induced fractal defects states is shown, exhibiting self-similarity better than 90% over three orders of magnitude in typical length scales. With use of polarization optical microscopy and numerical modelling we characterize the coupling of the fractal geometry to the nematic director field. Explicit generation of topological defects following an exponential-law dependency is shown reaching few 100 already at fractal iteration four. This work represents a route for generation of fractal topological defect states in responsive soft matter.
COBISS.SI-ID: 30202663
We used an advanced method of 3D fluorescent confocal microscopy to reconstruct the order of molecules in thermally quenched micrometre-sized droplets of chiral nematic liquid crystals and discover various topological states which include strings of topological defects and point defects with multiples of unit topological charge. The ordering of molecules around these topological defects is similar to polyvalent atoms and enables the formation of complex topological structures, reminiscent of molecules.
COBISS.SI-ID: 30270503
In this article, we show how several abstract concepts manifest elegantly as observable and measurable features in nematic colloids with knotted disclination lines. Construction of medial graphs, surfaces, and Jones polynomials is showcased directly on experimental images, and adapted for the specific system of colloidal crystals in a twisted nematic cell. We discuss the correspondence between topological concepts and experimental observation, which is essential for building the bridge between mathematical and physical communities.
COBISS.SI-ID: 2787940