LiNbO3 integrated system for opto-microfluidic sensing

•Realization of a fully integrated opto-microfluidics platform entirely made on lithium niobate (LiNbO3) crystals for real-time data analysis.•Detection of single droplet passage and estimation of its size without the need of any imaging processing.•High quality performances in term of optical triggering, reproducibility and stability in time.•Portable device with increased affordability better than 50% respect standard techniques. In this work, we realized and tested an integrated opto-microfluidics platform entirely made on lithium niobate (LiNbO3) crystals, able to detect the single droplet passage and estimate its size without the need of any imaging processing. It is based on the coupling of a self-aligned integrated optical stage, made of an array of optical waveguides, to a microfluidic circuit such as a T-junction or Cross-junction engraved in the same substrate. The platform presented high quality performances in terms of optical triggering, reproducibility and stability in time, allowing in real-time data analysis. The comparison with standard approaches using microscopes and fast camera imagining acquisition and relative post-processing, showed an increased capability better than 50%. The demonstrated feasibility of integration of these two stages will allow the realization of a Lab-On-a-Chip on a monolithic substrate of lithium niobate, exploiting its multiple applications for manipulation of droplets.