A flexible skin piloerection monitoring sensor

We present a capacitive-type flexible micro sensor for measurement of the human skin piloerection arisen from sudden emotional and environmental change. The present skin piloerction monitoring methods are limited in objective and quantitative measurement by physical disturbance stimulation to the skin due to its bulky size and heavy weight. The proposed flexible skin piloerection monitoring sensor is composed of 3×3 spiral coplanar capacitor array using conductive polymer for having high capacitive density and thin enough thickness to be attached to human skin. The performance of the skin piloerection monitoring sensor is characterized using the artificial bump, representing human skin goosebump; thus, resulting in the sensitivity of -0.00252%/μm and the nonlinearity of 25.9% for the artificial goosebump deformation in the range of 0~326μm. We also verified two successive human skin piloerection having 3.5s duration on the subject´s dorsal forearms, thus resulting in the capacitance change of -6.2fF and -9.2fF for the piloerection intensity of 145μm and 194μm, respectively.