Fig. 5From: Epidermal Differential Impedance Sensor for Conformal Skin Hydration MonitoringData that establish the relationships between hydration levels measured by a CMM and the differences in impedance amplitude and phase values measured by channels 4 (i.e. measuring) and 5 (i.e. reference) by an epidermal hydration sensor. The left frames a, c show the directly measured data; the right frames b, d show results after calibrationBack to article page