Abstract: A reference electrode of an electrochemical sensor includes a substrate having a well, a channel, and a conductive element. The well extends from a first surface of a substrate towards a second surface of the substrate. The channel is within the substrate. A longitudinal axis of the channel may be substantially perpendicular to a longitudinal axis of the well. The channel has a first end connected to the well and a second end that is in contact with the conductive element. The channel and the wells form a flow path of a conductive medium. The flow path may be coupled to a manipulating element such as an agitating element or heating element that promotes flow of the membrane.