To collect data, an electronic device transmits a signal on an output channel of the headset jack to provide an excitation signal to a sensor for measuring a physical quantity. The top and peripheral sidewall together form a cap-shaped member that is hollow with the peripheral sidewall having an inner surface and an outer surface. The cathode flow field plate further has a plurality of flow channels formed at the channel side for enabling fluid flowing along the flow channels to promote electrochemical reaction through the MEA so as to generate electrical energy.