This paper presents a feasibility study for a non-wearable, conformal, low cost, and\ndisposable antenna-based sensor for non-invasive hydration monitoring using sweat. It is composed\nof a patch antenna implemented on a cellulose filter paper substrate and operating in the range\n2â??4 GHz. The paper substrate can absorb liquids, such as sweat on the skin, through two slots\nincorporated within the antenna structure. Thus, the substrate dielectric properties are altered\naccording to the properties of the absorbed liquid. Changes in reflection-based measurements are\nused to analyze salt solutions and artificial sweat, specifically the amount of sampled solution and\nthe sodium chloride (NaCl) concentration. Using the shift in resonant frequency and magnitude of\nthe reflection coefficient, NaCl concentrations in the range of 8.5â??200 mmol/L, representing different\nhydration states, are detected. The measurements demonstrate the feasibility of using microwave\nbased measurements for hydration monitoring using sweat.
Loading....