Microstructure design and optimization of high-sensitivity interdigital capacitive humidity sensor based on uncertainty analysis

The microstructure of the interdigital capacitive humidity sensor plays a critical role in achieving high sensitivity in measurements. Performing a quantitative evaluation to assess the influence of structural parameters on sensor sensitivity is vital for improving the overall performance of the sensor. In this paper, a theoretical mathematical model and a structural uncertainty propagation model are developed for the interdigitated capacitive humidity sensor, considering the uncertain errors that occur during the processing and measurement processes. A quantitative analysis is conducted to investigate the impact of each structural component and its corresponding uncertainty on the output sensitivity. Moreover, by integrating the two constructed models, the paper formulates an optimal equation for sensor performance that mitigates the impact of structural errors on the system while improving sensor sensitivity. Researchers have the flexibility to adjust sensor material, environmental conditions, structural components, and other parameter variables within the model, according to specific application requirements, to achieve the optimal design scheme for a sensor with specific materials and structure. The proposed method and model presented in this article have undergone verification using finite element physical simulation. The sensitivity model achieves an accuracy rate of 94.45%, whereas the uncertainty model achieves an accuracy rate of 81.96%. Additionally, the model reduces the calculation time to 1/550th and the required computational resources to 1/5th of the simulation, thereby greatly improving the efficiency of sensor optimization design.