Hydration measurements of the stratum corneum: comparison between the capacitance method (digital version of the Corneometer CM 825^®) and the impedance method (Skicon‐200EX^®)

Abstract

Both instruments allow a certain calibration and both give good estimates of the SC hydration.

Multimodal epidermal devices for hydration monitoring

“…Computational studies of the thermal and electrical responses relied on commercial software from ABAQUS 9 and COMSOL 10 , respectively. For the former, the encapsulation layer (Ecoflex), skin, and heater used axisymmetric heat transfer elements (DCAX4).…”

“…Thermal measurements (1) are less susceptible to contact resistances due to the increased penetration depth of the thermal signal (as seen in the FEA shown in Figure 4; (2) do not require direct contact, allowing for a soft elastomeric layer to provide further insulation from leakage currents into the skin (in addition to the stiff, PI layer) 15 , in addition to imparting robustness to the device, unlike impedancebased sensors where the electrodes need be in direct contact with skin 19 ; and (3) offer advanced capabilities in temperature 16 and blood flow mapping 17 using similar resistive elements. Impedance-based measurements (1) build on an extensive library of knowledge on skin-based electrical measurements 25,44 ; (2) provide versatility in probing volumes derived from the ability to use a wide range of applied frequencies 45 ; (3) yield physical information about skin through both the capacitive reactance (permittivity) and the resistance (conductivity) 23 embedded in the measured impedance; and (4) enable comparisons with existing commercial measurements, almost all of which rely on electrical sensing 9 . Both measurements offer comparably short speeds, with a complete impedance spectral sweep requiring roughly the same amount of time as a time-multiplexed measurement of 16 individual ETPS elements (both~10 s).…”

“…Traditional sensors of skin hydration rely on capacitive or impedance-based methodologies in which mechanical force establishes contact to rigid measurement electrodes 9,10 . The most commonly used tool for making such measurements, the corneometer (Courage+Khazaka electronic GmbH), relies on capacitive sensing based on concentric ring electrodes (circular inner electrode~5 mm diameter, annular outer electrode~9 mm inner diameter,~22 mm outer diameter 10 ), with typical operating frequencies in the MHz range.…”

A new topical panthenol-containing emollient: skin-moisturizing effect following single and prolonged usage in healthy adults, and tolerability in healthy infants

“…Capacitance is considered a function of SC hydration (16). Measurements were performed on each of the two test areas at baseline as well as at 2, 4, 8, and 24 h after the first and single application of NTP-CE.…”

Moisturizing Effects of Diglycerol Combined with Glycerol on Human Stratum Corneum

“…, ranging from 0 to 120 a.u. A higher capacitance value indicates a higher moisturizing effect on the skin 19,20 .…”