Currently, manufactures are focusing on developing sensor products featured with increased miniaturization and lower cost. Several current technology trends are driving the need for miniaturization, compactness and low power consumption sensor solutions. On the other hand, benefitted from the significant progress in the development of advanced silicon photonics and MEMS technologies, silicon nanophotonic sensing devices become candidates to meet the high sensitivity sensor requirement, and to be used across a broad range of applications, including environmental monitoring, safety hazard detection, health monitoring and industry applications.

The particular truth, making silicon nanophotonic sensors to be attractive, is that environmental changes could be represented as a change in frequency of the light detected, as well as the change of the signal strength. It much benefits the detection system with high sensitivity and resolution. For instance, working as multifunction and smart gas sensors, the detection of concentration becomes possible by measuring the influence on the optical properties of silicon nanophotonic sensors such as micro-ring resonator and optomechanical resonator, etc., is an excellent transducer for environmental sensing (including temperature, humidity, chemical, carbon dioxide gases, etc.) due to their intrinsic advantages of high Q-factor, large extinction ratio, and high compactness. Meanwhile, their transmission spectra heavily depend on the resonator’s surrounding environment. In this paper, different types of silicon nanophotonic sensors will be highlighted and their potential applications in environmental protection, safety hazard detection, health monitoring, etc., will be discussed. Silicon nanophotonic sensors offer advantages over conventional sensors for low cost, low power consumption, small size and high sensitivity etc.