Pressed-onto 3Omega method for measuring the thermal properties of gas diffusion layers of fuel cells and the like

3Omega measurements of the thermal conductivity often require a high preparation effort due to processing in clean-room. In this work, first results are presented of a new method which simplified the use of the 3Omega technique. The method has been tested successfully on gas diffusion layers of Polymer Electrolyte Membrane Fuel Cells as well as materials with well-known properties such as Teflon, Lithosil, Macor, iron silicide or chromel. In the " pressed onto " 3Omega method, a micro-heater is fabricated on a flexible substrate foil. The micro-heater on its substrate is pressed on the surface of the sample for measurements. The micro-heater is integrated into the sample holder and belongs to the measurement systems; no costly sample preparation is needed. The measurement is non-destructive. A thin electrical insulation of the micro-heater enables the measurement of conductive samples. The method could be potentially integrated in a fuel cell thus being suitable for in-situ measurement and feedback control loops.