Photo‐Induced Electric Field Effects on Water Droplets Generated in a LiNbO<sub>3</sub> Opto‐Microfluidic Platform
Giovanni Bragato, Annamaria Zaltron, Michele Zanardi, Riccardo Zamboni, Maddalena De Ros, C. Sada
Abstract
Abstract In this work, droplets elongation as a result of the photo‐induced photovoltaic electric field is presented and modeled. Moving water droplets are generated in microfluidics channels by means of a droplet‐based opto‐microfluidic platform integrated in lithium niobate (LN). A cross‐junction is engraved on the substrate as droplets generator, on top of which a z‐cut iron‐doped lithium niobate (Fe:LN) crystal is placed in order to build up photo‐induced electric field as a result of photovoltaic effect promoted upon suitable illumination. Droplets detection is realized by optical waveguides, designed in a Mach‐Zehnder Interferometer (MZI) configuration on the same substrate. The dynamics of droplet elongation is investigated, highlighting the impact of the photovoltaic electric field on the droplet dimension and surface tension.