Each cell uses a conductive, porous separator. And each cell usually requires four gas seals. The typical proton exchange membrane, or PEM, fuel cell consists of a series of stacked individual cells, with each cell composed of a flow field plate and a membrane electrode assembly. The protons flow through the membrane, while the electrons run through an electrical circuit. Voltage varies according to the number of individual cells making up a stack.
More cells mean higher voltage.
According to Hockaday, the Manhattan Scientifics design dispenses with bipolar stacking, minimizing an expensive, painstaking assembly. Its fuel cells are manufactured in much the same manner as a circuit board. A thin plastic film is first tracked with nuclear particles. It is then etched to produce a uniformly distributed array of cone-shaped pores, each approximately 20 microns in diameter. Metals are sputtered over the substrate using thin-film vacuum deposition, forming a selectively permeable film over the pores.