Development of a miniaturised electronic nose integrated into a smartwatch

A prototype of an electronic nose integrated into a smartwatch to monitor ambient air pollution is described in this work. The device contains four metal oxide semiconductor sensors, one temperature/humidity sensor, and an accelerometer. The device allows to send data wirelessly via Bluetooth to a SmartPhone and visualize it in a display. Measurements are done with different chemical compounds that are harmful to human health, including toluene, xylene, ethylbenzene, carbon dioxide, and methane. Principal component analysis is used to verify the discrimination capabilities of the device and temporary response is used to test the detection capabilities with different concentrations. The device designed can discriminate between different gas mixtures and also detect different concentrations of the chemical compounds. This wearable device could be used for different applications, since monitoring air quality, detection of Toxic Industrial Chemicals and helping people who has lost his sense of smell, among other aplications.