MIRIS aims to develop a new technology for next-generation monolithic image sensors sensitive in the near-infrared (NIR) wavelength range. Implementation of novel, thin-film photoactive materials and the integration of this organic photodiode layer on top of a CMOS read-out chip, will enable order-of-magnitude cost-saving together with resolution improvement beyond the level achievable by the currently widespread hybrid imager technology. The image sensor envisioned in MIRIS comprises advancements in photoactive materials, a photodetector concept, readout circuit design and thin-film monolithic integration. As the main benchmark is the radiation spectrum, the first figure-of-merit is the sensitivity in the wavelength range above 0.7 micrometre and up to 2 µm. On one hand, this ensure extension of silicon-based imager spectrum above visible and on the other hand, this enables near-infrared sensitivity in a monolithic imager. For the latter, this means a cost-saving of approximately factor 10 versus the typical near-infrared imagers using InGaAs detector chip hybridized to a silicon readout chip by micro bumps. Additionally, the monolithic approach enables high resolution not achievable in hybrid technology (below 5 micrometer pixel pitch).