Embodiments described herein may include devices and methods of manufacturing sensors for monitoring physiological parameters of a patient. Specifically, embodiments disclose the use of conductive and nonconductive coating materials to increase comfort of sensor and increase accuracy of the parameters measured. The sensor may include a flexible circuit and an optical device with an active face. A generally opaque, nonconductive coating may be disposed over the optical device, except for the active face, which allows for passage of light to the active face. The nonconductive coating may comprise a medical grade silicone of a specified thickness. A second conductive layer may be disposed on a portion of the conductive layer, to provide a Faraday shield for the optical device.