Preparation of nest-like CeO2 humidity sensing material and its application in eye strain monitoring

With the continuous development of science and technology, the application field of humidity sensors has gradually expanded from industrial and agricultural detection to intelligent fields. Recently, wearable humidity sensors have demonstrated great promise in monitoring human behaviors, which in turn has attracted much attention from researchers. To enhance the humidity sensing performance of materials and enable their application in intelligent sensing, nest-like CeO2 nanomaterials were synthesized by adjusting reaction conditions to control the assembly of nanosheets. The nest-like CeO2 was investigated using techniques such as X-ray photoelectron spectroscopy, infrared, and scanning electron microscopy. The test results indicate that the nest-like morphology and the presence of unsaturated bonds caused by Ce3+ enhance the sensing performance of the CeO2 humidity sensor. In the air environment, the sensitivity was up to four orders of magnitude (6565) when the humidity was varied in the range of 11–97 % relative humidity (RH). Additionally, it exhibited short response/recovery time of 0.5 s/4.3 s, minimal humidity hysteresis (1.0 %), and excellent long-term stability. Moreover, the exceptional humidity sensing performance of the nest-like CeO2 enables its innovative applications in monitoring blink frequency and eye strain reminders, providing valuable research insights for convenient medical detection.