Zinc oxide andor zinc carbonate coated particles, methods of coating particles with zinc oxide andor zinc carbonate, and various applications of such coated particles, including applications in cosmetics, rubber, and other polymer materials, are disclosed. The rotation sensor has slip rings covered with conductive synthetic resin having small coefficient of friction, allowing the contact pressure of brushes disposed in sliding contact with the slip rings to be kept low and the life duration of the slip rings to be prolonged. Gel flow barriers protect electronics board features from unwanted non-conductive gel. 1 mgmL; and at least one antioxidant in a concentration of at least 0.