NOVELTY - Creation of an indicator fixed ion-exchange membrane comprises dissolving an indicator into a solvent to create an indicator solution. An ion-exchange membrane is contacted with the indicator solution. The indicator of the indicator solution is fixed throughout the membrane to create an indicator fixed ion-exchange membrane.    USE - The method is used for creating indicator fixed ion-exchange membrane useful in fuel cell testing device (claimed). It is used for evaluating individual components of a fuel cell and assemblies of greater than or equal to2 components of the fuel cell.    ADVANTAGE - The fuel cell testing device using the membrane is both a cost efficient and effective device for determining fuel cell component characteristic(s). The membrane is capable of assisting in the evaluation of component performance functions under conditions that simulate real fuel cell operation. It assists testing without requiring an exchange or addition of components to the fuel cell. It provides for a quick cost-effective testing paradigm for components. It has the ability to visualize the gas diffusion activity in ion-exchange half-cell reactions due to the integration of an indicator, e.g. fluorescent pH detection or a calorimetric dye with the ion-exchange membrane. No additional physical elements beyond the standard components of a fuel cell are required to investigate a characteristic of a fuel cell component. The membrane provides a luminescent or colorimetric signal as to the characteristic of fuel cell component(s). It focuses on parameters related to spatial visualization of gas diffusion, catalyst uniformity verification, and fuel delivery through gas diffusion layer(s) to the catalyst based on the visual concentration gradient of the membrane.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) indicator fixed ion-exchange membrane; and    (2) fuel cell testing device (10) comprising a housing with a fluid entrance port (12) and a visible membrane containment area, a catalyst received at the visible membrane containment area, a source of an ionizable fluid connected to the fluid entrance port so that an ionizable fluid can flow from the source into the housing through the fluid entrance port and react with the catalyst to produce ions, the indicator fixed ion-exchange membrane for responding to an ionic concentration gradient and received at the membrane containment area and in ionic connection with the catalyst, and a fuel cell component received in the housing.    The indicator fixed ion-exchange membrane experiences an ionic concentration gradient and alters its response to light, indicating fuel cell component characteristic(s).    DESCRIPTION OF DRAWING(S) - The figure is a side schematic representation of a fluid diffusion testing apparatus.    Fuel cell testing device (10)    Fluid entrance port (12)    Flange (14)    Half-cell electrode assembly (16)