Flow field

Flow field designs are provided, as well as flow field devices employing the subject flow field designs. A fluid distribution assembly is provided comprising a flow field device and a fluid transport layer disposed between the flow field device and a target area, where, for at least one finite non-zero flow rate and at least one use rate of an active component of the fluid in the fluid transport layer, lateral flux of the active component varies by no more than 35% through at least 90% of all overland portions of said fluid transport layer. In one embodiment, the flow field device comprises a flow field comprising a serpentine channel, comprising non-parallel sequential major segments. In a further embodiment, the angles between successive major segments of the serpentine channel vary progressively.