Concentration Measurements of Ethanol in Water Based on RFID-UHF Flexible Sensor for Sterilization Against SARS-CoV

In this work, we present a UHF-RFID-based noninvasive sensor to measure the concentration of ethanol in water using the volume fraction of liquids in mixture solutions. The sensing system operates at the UHF band (860–928 MHz). The concentration of ethanol in water affects the dielectric properties of the solution and therefore the antenna sensitivity of the RFID tag. This sensor operates by measuring the change in permittivity of a solution because of the change in concentration of ethanol in water. We propose a flexible RFID-Tag sensor a low-cost alternative to identify the possible sensitivity of tag changes and is able to detect a variation of 25% in ethanol in 9 ml of deionized water (DI-Water). The solution is useful in avoiding counterfeit ethanol solutions that may be toxic. The experimental setup is inexpensive, portable, quick, and contactless. We present results for ethanol solutions ranging from 25% to 100% in a small tube container.