Unique Noncontact Monitoring of Human Respiration and Sweat Evaporation Using a CsPb2Br5-Based Sensor

Respiration monitoring and human sweat sensing have promising application prospects in personal healthcare data collection, disease diagnostics, and the effective prevention of human-to-human transmission of fatal viruses. Here, we have introduced a unique respiration monitoring and touchless sensing system based on a CsPb2Br5/BaTiO3 humidity-sensing layer operated by water-induced interfacial polarization and prepared using a facile aerosol deposition process. Based on the relationship between sensing ability and layer thickness, the sensing device with a 1.0 mu m thick layer was found to exhibit optimal sensing performance, a result of its ideal microstructure. This sensor also exhibits the highest electrical signal variation at 0.5 kHz due to a substantial polarizability difference between high and low humidity. As a result, the CsPb2Br5/BaTiO3 sensing device shows the best signal variation of all types of breath-monitoring devices reported to date when used to monitor sudden changes in respiratory rates in diverse situations. Furthermore, the sensor can effectively detect sweat evaporation when placed 1 cm from the skin, including subtle changes in capacitance caused by finger area and motion, skin moisture, and contact time. This ultrasensitive sensor, with its fast response, provides a potential new sensing platform for the longterm daily monitoring of respiration and sweat evaporation.

Automated summary

Respiration monitoring and human sweat sensing have great potential for application in personal healthcare data collection, disease diagnostics, and preventing human-to-human transmission of deadly viruses. A unique sensing system based on a CsPb2Br5/BaTiO3 humidity-sensing layer was introduced, showing optimal performance with a 1.0 μm thick layer due to its ideal microstructure. The sensor offers high electrical signal variation at 0.5 kHz, making it the best device for monitoring sudden changes in respiratory rates and detecting sweat evaporation with ultrasensitive capabilities.