Evaluation of a novel transepidermal water loss sensor

Recently we have developed a novel microsensor to measure the transepidermal water loss (TEWL) of human skin. The sensor is based on an interdigital electrode system covered with a highly hygroscopic salt film. In this paper we present a new method to evaluate and calibrate the sensor device. Different TEWL values are imitated by a variable humidity source. We demonstrate the very high sensitivity of our TEWL sensor. The output signal represented by the conductance of the sensor varies over six orders of magnitude in the relevant TEWL range between 2 and 60 g/(m/sup 2/h). Our precise calibration method is very important for the reliable medical diagnosis of skin diseases.