A fuel cell uses porous metal layers attached on a flex substrate for
delivery of liquid fuel to the active catalytic areas on the anodic side.
The flex substrate may form an enclosed package such that the liquid fuel
can be contained in the enclosed volume and the air can freely exchange
with the cathode side of the fuel cell without the need of microchannels
and plumbing for mass transporting both fuel and oxygen to the active
catalytic area. The porous metal provides a large surface are for the
catalytic reaction to occur.