SnO 2 Sensors For a Portable Transdermal Alcohol Detector Via Finger

In this work we report, for the first time, on the fabrication of portable transdermal alcohol detector device, based on lab made tin oxide (SnO 2 ) gas sensors. This method allowed us the continuous monitoring of alcohol in a non-invasive way with low cost and easy fabrication process. From the calibration results, the fabricated sensors exhibited high sensitivity, with fast detection and good stability, toward a wide range of ethanol concentrations. Additionally, they showed high immunity to elevate relative humidity percentages. Real time transdermal alcohol monitoring was performed on a volunteer. Twenty minutes after drinking 50 ml of tequila, the skin starts to emit alcohol and the sensor resistance begins to decrease. Alongside to this, breath alcohol measurements were simultaneously collected by using DRAGGER 6820 certified breathalyzer. The results revealed a consistent correspondence between the kinetics of blood, breath and perspiration, which validate the developed device reported in this work.