Abstract: A bipolar plate assembly for a fuel cell includes a first bipolar sheet having elongated lands formed thereon each defining secondary channels therein. The first bipolar sheet further includes primary channels formed between adjacent elongated lands. The first bipolar sheet includes an active area at which fluids flowing through the primary and secondary channels electrochemically react with an adjacent gas diffusion layer of the fuel cell. Top surfaces of the elongated lands include injectors formed as a hole in the top surfaces and located in the active area of the first bipolar sheet. Fluid flowing through the secondary channels is forced through the injectors, subsequently into the adjacent gas diffusion layer, and subsequently into and adjacent primary channel.

Abstract: The present disclosure generally relates to systems and methods for assessing the health of a fuel cell stack including collecting fuel cell stack operating data by a controller including stack voltage data and cell voltage monitoring data and determining the trust in the collected data, processing stack voltage data and cell voltage monitoring data by the controller to identify bad channels and weak cells amongst fuel cells included in the fuel cell stack, tracking the state of health of the fuel cell stack by the controller, and assessing the health of the fuel cell stack by the controller.

Abstract: A humidification device includes a tubular mass exchanger fluidically coupled to receive intake air stream and transfer intake air stream to an intake air inlet of a fuel cell stack. The humidification device includes a housing configured to house the tubular mass exchanger to define a void therebetween. The housing defines at least one housing inlet opening fluidically coupled to direct an exhaust air stream output by the fuel cells tack into the void. The housing defines at least one housing outlet opening fluidically coupled to direct the exhaust air stream away from within the housing. The tubular mass exchanger is configured to extract water vapor from the exhaust air stream and transfer the extracted water vapor to the intake air stream flowing within the tubular mass exchanger to humidify the intake air stream to generate a humidified intake air stream.

Abstract: The present disclosure generally relates to systems and methods for using a relative humidity sensor in a cathode exhaust stream of a fuel cell stack to optimize the performance and efficiency of the fuel cell stack.

Abstract: Various embodiments are described herein for methods and devices that relate to a drive mechanism that can be used in an external heat engine to control the motion of the pistons and obtain increased engine power and/or efficiency. Through control of the piston motion a non-sinusoidal piston motion can be generated which can improve engine performance by enabling an engine to more closely follow an ideal thermodynamic cycle.