Transepidermal Potential of the Stretched Skin

The electrical response of the skin to mechanical stretches is reported here. The electrical potential difference across the epidermis, i.e., transepidermal potential (TEP) of porcine skin samples subjected to cyclic stretching, was measured in real time to observe electrochemical change in epidermal tissue. In addition to a conventional method of TEP measurement for the whole of skin sample, a probe-Type system with a fine-needle salt bridge was used for direct measurement of TEP at a targeted local point of the skin. TEP decreased with the increased mechanical stretches, and the change of TEP was found to be mostly occurred in the epidermis but not dermis nor hypodermis by comparing the results of conventional and the probe-Type methods. The observed change of TEP value was quick, reversible, and strain-dependent. Considering from such characteristic behaviors, one of the possible mechanisms of the modulation of TEP would be influence of the streaming potential caused by the fluid flow during the physical deformation of the epidermis.