Figure 1.

The Epsilon is a novel instrument for measuring near‐surface dielectric permittivity (ε) and contact imaging of the skin. Its proprietary electronics and signal processing algorithms map the sensor's nonlinear signals onto a calibrated scale for measuring properties such as stratum corneum hydration. A, The Epsilon instrument on the parking stand. B, A measurement performed on the inner arm. C, Close‐up of the Epsilon measurement head with the metal bezel. D, The sensor surface embedded in an epoxy frame. E, Typical contact image of the inner forearm skin. F, A contact image of the skin in the face with visible sweat gland activity