材料期刊网

The moisture content measurement of human skin is a significant way to assess skin conditions and diagnose diseases that influence skin function. The necessity of evaluating the efficacy of a cosmetic product makes it important to improve the accuracy and reproducibility of the measurement. A pair of interdigitated gold electrodes was fabricated on the printed circuit board (PCB) substrate and utilized directly in contact with the measured skin. A square-wave voltage at a single frequency was applied to the electrodes and the corresponding response current was measured to get the equivalent impedance of human skin. Since it's easy to generate and control a square-wave signal by digital electric circuits, this method is suitable to be used in the portable application. The experimental results indicate that good repeatability and satisfied accuracy can be obtained by this method.