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Liquids attain their equilibrium shape due to the surface tension. In recent years, the minimized spherical surface dictated by the interfacial tension of simple oils suspended in surfactants has successfully transformed into vivid structures of non-spherical geometries. Especially, partially ordered liquids--liquid crystals (LCs)--carry bulk elasticity show shape transformation of LC droplets into fibers using binary mixtures started two decades ago. The effort to control the LC droplet shape effectively continues using specially synthesized surfactants, fluorinated LCs, and polydispersed oligomers to date. However, each reported system stands out uniquely for the successful shape transformation of LC droplets. So far, no reliable method works for arbitrary LC compounds and phases. In this talk, I present our recent work tackling the shape transformation of LC droplets into spectacular curved fibers of uniform diameter by balancing the LC bulk elasticity and the interfacial energy. Our approach to this problem is universal and applicable to any LC material and phase. In detail, we have used a combination of surfactant, co-surfactant dispersed in the aqueous medium, and LC material, respectively, to achieve the sign reversal of the interfacial tension, which triggers the self-shaping possibility with the external thermal stimuli. Further, the tuning of the LC elastic constants with the temperature drives the LC droplet into controllable fiber diameters with branches and back reversibly (Fig.1). In addition, the nematic to SmA LC phase transition drives the fiber structures into monodispersed micro-droplets with a tunable diameter dictated by the cooling rate. The extension of the self-shaping phenomenon in the SmC phase opens the route to generate helical fibers with an equal probability of right and left-handed helices. Moreover, the SmC* phase shows life-like self-shaping LC shell structures analogous to the bio-membranes in living systems. All these fibers carry topological defects and the highest possible surface quality. Therefore, all these curved structures guide light efficiently and potential for topological photonics. [ABSTRACT FROM AUTHOR]

Using atomically-resolved scanning tunneling microscopy and spectroscopy, we probe the structure and the electronic properties of sub-nanometer MoS[SUB2] single wall nanotubes (SWNT) at room temperature. We find that, the nanotubes condense uniformly in ropes with achiral atomic structure and conical ends. Scanning tunneling spectroscopy measurements indicate a semiconducting behavior that is slightly dependent on their structural parameters. The contrast of atomic scale topographic and current STM images reveal the details of the lattice structure which allow us to identify clearly the locations of both atoms on the tube surface. By using AFM as a manipulating tool, we are able to transport or distort single MoS[SUB2] nanotubes. We will show how to artificially produce kinks, draw a circle, and write letters or numbers from MoS[SUB2] SWNT using AFM techniques. [ABSTRACT FROM AUTHOR]