Integrated opto-microfluidics platforms in lithium niobate crystals for sensing applications

In micro-analytical chemistry and biology applications, droplet microfluidic technology holds great promise for efficient lab-on-chip systems where higher levels of integration of different stages on the same platform are constantly realized. In this scenario, recent results on the full integration of opto-microfluidic functionalities in lithium niobate (LiNbO3) crystals will be presented. Droplets generated in T-junctions directly engraved in a LiNbO3 substrate, can be illuminated by optical waveguides realised in the material. By exploiting holographic gratings therein recorded, the optical properties of the droplets constituents can be monitored paving the way to new compact optical sensor prototypes. In this work we will describe the recent results on the realisation of each of the mentioned stages: Laser ablation will be exploited to realize highly performant T-junction droplet generators to be coupled with optical waveguides made by standard Ti – in diffusion on which a holographic stage is implemented thanks to Fe co-diffusion. Consequently, the challenges in understanding the physical phenomena and future perspectives for new application fields will be outlined.