 we have developed several novel photonic materials and devices for on-chip mid-IR sensing applications. These include pedestal waveguides, directional couplers, photonic crystal cavities, and microdisk resonators, all fabricated on silicon. Additionally, we have developed polymer-based functionalization layers to enhance the sensitivity and selectivity of these sensors. Furthermore, we have successfully integrated these components into a single monolithic silicon platform, enabling efficient evanescent coupling between the waveguides and the detectors. This article was authored by Vivexing Kan et al.