A Novel Method for Measuring the Temperature Distribution Within the Fuel Cell Using Array Micro Sensors

The fuel cell has the potential to become an important source of electric power. However, measuring the temperature inside the fuel cell is difficult. Hence, in this investigation, array of micro sensors are set up inside a fuel cell to measure the temperature distribution. The substrate of the bipolar plate in a fuel cell is made of stainless steel (SS-316) and the electroforming technique is implemented to fabricate channels in the stainless steel substrate. Then NEMS (Micro-Electro-Mechanical Systems) technologies are employed to fabricate the platinum temperature sensor on the rib of a channel of stainless steel. The major advantages of array micro platinum temperature sensors are their small volume, high accuracy, short response time, simplicity in their fabrication, their mass production and ability to measure the temperature precisely and more effectively than a traditional thermocouple. The stainless steel bipolar plate is a good conductor of electric and heat. It has high mechanical strength and is non-porous. The graphite bipolar plate does not have such extensive advantages. This work electroforms a channel on stainless steel and then fabricates an array of micro temperature sensors on the rib of the channel. It is used to measure the temperature distribution at all locations in a fuel cell with a metallic bipolar plate. In the experiment, the temperature- is measured from 31 to 80 degrees Celsius and its resistance range from 0.593 to 0.649 ohm. The experimental results demonstrate that the temperature was almost linearly related to the resistance and the accuracy and sensitivity are under 1 degrees Celsius and 1.85×10⁻³ over degrees Celsius, respectively.