3D self-connected microwire
We show that nematic liquid crystals may be used to self-assemble microwires that moreover, automatically connect to designated electrodes. The process works in three dimensions and apparently, is without any rival for the moment . Three steps are necessary.
First, the space between the substrates to be connected is filled with a nematic liquid crystal, their surfaces being treated in order to force planar anchoring conditions with conflicting orientations on the electrodes to be connected. In this manner, a disclination line (i.e. a defect line or a topological singularity) is created at the place where to produce the microwire.
Then, we use another interesting property of nematic liquid crystals that colloidal particles initially dispersed in them, are dragged toward the disclination lines and eventually become trapped onto them [see : Colloidal interaction in the nematic phase]. In this manner, we get a micronecklace in the place of the disclination (Fig.1).
Finally, we thoroughly join the particles together on applying a voltage difference between the particles in order to polymerize monomers solved in the liquid crystal. After a few hours, polymerization sticks the particles to one another and the micronecklace turns into a cohesive microwire (Fig.2). Clearly, the wire’s quality is not satisfactory yet, but it can be improved. In particular, its size can be reduced, for example, by decreasing the particles’ size and concentration.
 Jean-Baptiste Fleury, David Pires, Yves Galerne ; Phys. Rev. Lett. 103, 267801 (2009) ; Self-connected 3D architecture of microwires