The invention provides an improved electrotransport drug delivery system for analgesic drugs, namely fentanyl and sufentanil. In the spin valve sensor, the trilayer seed layer structure is located between a first read gap layer and a ferromagnetic free layer. The module data may reference a second module, the second module being associated with the first source to enable communication between the first and second sources. Accordingly, the number of electrons which can be supplied onto the surface of a chemical conversion film can be increased during a voltage application in an electrodeposition coating process, and reducing reaction at a cathode can be promoted.