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This paper describes the implementation of a low-cost technology platform for fluorescence-based optochemical sensors made up of arrays of multimode waveguides and coupling structures integrated onto a flexible substrate. Such a configuration is ideal for multi-analyte detection owing to a possibility of future integration of different dyes in each waveguides. The presence of light sources, fluorescent sensing elements and photodetectors in a foil platform makes it a compact optochemical sensor, which has wide-range of applications in medical, biochemical, and environmental diagnostics. Flexible lightguides fabricated using soft-lithography based replication techniques, are used in combination with 45° micromirror coupling structures, having a loss of 0.5dB. Fluorescent dyes are incorporated with the lightguides enabling a detection of shift in fluorescence-peaks in contact with gases, which are read-out at the detection. Initial measurements yielded promising results of the waveguides mixed with fluorescent dyes showing response to toluene.

This paper describes the development of a low-cost technology platform for fluorescence-based optochemical sensors. These sensors were constructed by incorporating fluorescent sensing elements in the core of multimode waveguides or lightguides, and have applications in medical, biochemical and environmental diagnostics. Flexible lightguides were fabricated either with silsesquioxane-based or PDMS-type optical polymers using photolithography or soft-lithography based replication techniques respectively. Spectral transmission characteristics were measured along with loss values obtained by cut-back measurements for several wavelengths from visible to mid-IR. Propagation losses as low as 0.14dB/cm were measured for 50 x 50 m2waveguides. For coupling light in and out of the waveguides, different types of coupling structures, e.g. 45� micromirror plugs were investigated.

This paper presents a study of selective ablation of thin organic films (LEP- Light Emitting Polymer, PEDOT:PSS- Poly 3,4-ethylenedioxythiophene: polystyrene sulfonate) by using 248 nm Excimer laser, on various kinds of multilayered SiN barrier foils for the development of Organic Light Emitting Diodes (OLED). Different Silicon Nitride (SiN) barrier foils with dedicated absorption spectra are taken into account for this purpose. The drive for looking into different types of SiN originates from the fact that the laser selective removal of a polymer without damage to the barrier layer underneath is challenging in the dynamic laser processing of thin films. The barrier is solely responsible for the proper encapsulation of the OLED stack. The main limitation of current OLED design is its shorter life span, which is directly related to the moisture or water permeation into the stack, leading to black spots. An optimization of laser parameters like fluence and number of shots has been carried out for the various types of SiN barrier foils. We are able to obtain a wider working process window for the selective removal of LEP and PEDOT:PSS from SiN barrier, by variation of the different types of SiN.