Polymer-on-glass is a suitable platform to develop biochemical photonic sensors. Indeed, low absorption of visible wavelength and low cost production of integrated photonic interconnects on polymer are important assets regarding biosensor industry. In parallel, integration trends also focus on the hybridization of digital microfluidic channels with optical microring resonators (MRR) forming complete sets of lab-on chip systems which would enable for example, reliable in-situ sensing of pollutants in water (e.g hexavalent chromium).
We describe efforts on design and fabrication of optical sensor operating at ?=505nm. The final device is constituted by grating couplers on tapers to perform efficient out-of plane lightcoupling, waveguides for light confinement and MRR for sensing. These planar structures with critical sub-micron features are realised on transparent glass substrates where the selected materials are SU-8 2000.5 (Curable UV polymer, n=1.57) for the guiding layer and water and/or Cytop (Amorphous Fluoropolymer, n=1.335) for the cladding layers. Finite difference time domain simulations (2D-FDTD) support the design of different elements and the large scale and multilevel integrated photonic structures are efficiently achieved by UV-NanoImprint Lithography (NIL).