Fast Response Graphene Foam/MoS₂-Based Humidity Sensor Based on Data-Driven Dynamic Compensation

A novel humidity sensor based on graphene foam combined with MoS2 was prepared in this article. MoS2/graphene foam (MGF) composite materials were synthesized by the atmospheric pressure chemical vapor deposition (CVD) method, and then transferred onto a glass substrate, and had electrodes prepared to complete sensor fabrication. Due to the high surface-to-volume ratio and network structure of sensing materials, humidity sensors exhibit shorter response and recovery times by allowing water molecules to be absorbed and released more quickly. Besides, this type of sensor also shows relatively linear sensitivity (0.04%/%RH between 10% and 90% RH) and good repeatability (the maximum offset within 0.41% at 60% RH), so that it can be used for respiratory monitoring. This provides a unique method for respiratory monitoring that can be applied in medical monitoring, with great potential for use. Moreover, to further enhance the dynamic performance of humidity sensors, a dynamic compensation method combined with system identification and particle swarm optimization (PSO) is proposed. By employing this approach, the identified dynamic mathematical model agrees well with the actual measurement results (95.67% in absorption and 91.09% in desorption). In the process of moisture absorption, the sensor component’s operational bandwidth is enhanced from 0.06 to 1.91 Hz, and the response time is shortened from 2.06 to 0.29 s. During desorption, the sensor component’s operational bandwidth is enhanced from 0.02 to 1.75 Hz, and the recovery time is shortened from 3.74 to 0.48 s. This dynamic compensation method offers a practical approach to enhance these sensors’ performance.