Monitoring of Soil Moisture and Human Breath Using Colorimetric Humidity Sensors

Abstract

The monitoring of soil moisture is essential to optimize plant growth, harvest, and water use, and respiration monitoring is one of the major vital signs of human health. Current soil moisture sensors are either costly or ineffective, and current breath sensors which also detect humidity levels are electronic-based with narrow humidity ranges. The following study targets these two needs by developing a cost-effective, high-sensitivity soil moisture sensor and breath monitor. Responsive interference coloration humidity sensors which utilize thin-film interference are applied to track soil moisture content over time, and to monitor breath humidity levels and respiratory rate in various scenarios. The ease of use and cost-effectiveness associated with the sensor and its analysis makes it suitable even for at-home use.