Integration of micro flow sensor and flexible substrate as GDL in micro fuel cell

The production of useable energy is today a global issue and the search for alternative energy sources is very challenging. Therefore, scientists have´ tried hard to identify new alternative energy sources. Fuel cells have potential as an indispensable source of electrical power. However, the mass production of fuel cells encounters various problems, which are yet to be solved, such as determining the fuel flow rate inside fuel cells. The product of the chemical reaction that proceeds in a fuel cell is water, which lowers the working efficiency of the cell and affects the fuel flow rate. No study of the fuel flow rate within a micro fuel cell has yet been published. Hence, in this work, micro flow sensors are fabricated on a flexible substrate as the gas diffusion layer (GDL) using micro-electro-mechanical systems (MEMS) within the micro fuel cell. The fundamental concept of the micro flow sensor is the use of two sets of micro temperature sensors plus and a set of heaters. The temperature difference between the two sensors is measured. The heater is also used to increase the working temperature of the fuel cell when the actual temperature is not favorable. The experimental results show an accuracy and sensitivity of the micro temperature sensor of 0.5 degC and 1.31 Omega/degC, respectively.