Electro-switchable polydimethylsiloxane-based optofluidics

Abstract

We report on the fabrication and characterization of a new generation of electro-switchable optofluidic devices based on flexible substrates, combined with the extraordinary properties of reconfigurable soft-materials. A conductive polydimethylsiloxane microstructure has been first sputtered with an Indium Tin Oxide (ITO) layer and then functionalized with an amorphous film of SiO(x). Then, the "layer" by "layer" microstructure has been infiltrated with an anisotropic and reconfigurable fluid (Nematic Liquid Crystal, NLC). The sample has been characterized in terms of morphological, optical and electro-optical properties: the soft-conductive microstructure exhibits a uniform and regular morphology, even after testing with mechanical stretching and deformations. Combination of the conductive ITO with the functionalization film (which has been employed for inducing in-plane alignment of NLC molecules) enables us to carry out a series of optical and electro-optical experiments; these confirm excellent properties in terms of a reconfigurable device and a diffractive element as well.