Modeling analysis and experimental verification of IDE humidity sensor integrated with PZT: Ultra-fast response and recovery times

Highly dynamic humidity monitoring is critically important across various fields. Rapid response and recovery times significantly enhance both the real-time performance and accuracy of sensors. This study introduces an innovative and efficient method for enhancing sensor dynamics by integrating piezoelectric ceramics (PZT) at the base of the sensor and utilizing its converse piezoelectric effect to significantly reduce response and recovery times. Several interdigital electrode (IDE) capacitive humidity sensors were developed using a WS₂ humidity-sensitive film, efficiently prepared via molten-salt-assisted chemical vapor deposition. Test results demonstrate that the introduction of PZT notably enhances the dynamic characteristics of the humidity sensor, reducing its response and recovery times to under 1 s. Additionally, the sensor exhibits high sensitivity, low hysteresis, excellent repeatability, and long-term stability. Due to these advantages, particularly its fast response, the sensor has been successfully applied in radiosonde systems and human respiratory monitoring, effectively capturing high-dynamic humidity changes in rapidly shifting high-altitude environments and in human breathing processes. The efficient preparation method, innovative structural design, and extremely fast response time make the WS₂ sensor with integrated PZT highly versatile for a wide range of applications.