Each rib is gold plated for low contact resistance and electrically isolated from the rest of the backing plate, allowing a real-time current density distribution with use of a multi-channel potentiostat.
Potentiostat can also make distributed high frequency resistance measurements to determine local electrolyte health and state of contact resistance.
X.-G. Yang, N. Burke, C.Y. Wang, K. Tajiri, and K. Shinohara, "Simultaneous Measurements of Species and Current Distributions in a Polymer Electrolyte Fuel Cell under Low-Humidity Operation," Journal of Electrochemical Society, Vol. 152, pp. A759-A766, 2005.
C.Y. Wang, "Fundamental models for fuel cell engineering," an invited review article for Chemical Reviews, Vol. 104, pp. 4727-4766, 2004.
M. M. Mench, C. Y. Wang, and M. Ishikawa, "In Situ Current Distribution Measurements in Polymer Electrolyte Fuel Cells," Journal of Electrochemical Society, Vol. 150, pp. A1052-A1059, 2003.