Abstract
The outside of the skin of the forearm is typically 15 mV more negative than the inside. Stretching the skin causes a reduction in the magnitude of this skin potential V, which we observe as a motion artifact 
. We seek to determine the origin of this motion artifact by successively stripping 12 layers of the skin using Scotch Tape. Between each stripping we measure artifact , 13 Hz impedance Z, and change in impedance 
. On the interior surface of the forearm, Z decreases with number of strippings. can be first either positive or negative, then is always negative and decreases linearly with Z. first remains constant and then decreases with Z and . and increase with stretch force following a logarithmic relationship. has a rectangular shape waveform, whereas the rising edge of shows a fast followed by a slow component and its falling edge decays exponentially with a large time constant. We have expanded the model of Thakor and Webster to best fit the waveform of and caused by stretch.
Keywords: skin, electrode, motion artifact, skin potential, skin impedance, skin model