A bipolar plate for an electrochemical fuel cell assembly, comprising: a first plurality of fluid flow channels (13, 73) extending across a first face of the bipolar plate between first inlet and outlet ports (18a, 18b) at opposing ends of the bipolar plate; a second plurality of fluid flow channels (22, 72) extending across a second opposing face of the bipolar plate between second inlet and outlet ports (19a, 19b) at opposing ends of the bipolar plate; and a third plurality of fluid flow channels (14, 74) extending between third inlet and outlet ports (17a, 17b) at opposing ends of the bipolar plate, the third plurality of fluid flow channels provided between first and second corrugated plates (11, 12, 51, 71) forming the first and second opposing faces of the bipolar plate, wherein the first, second and third channels (72, 73, 74) are coplanar, and characterised in that the bipolar plate further comprises: first inlet and outlet manifolds (15a, 15b) across the first face of the bipolar plate providing respective fluid connections between the first inlet and outlet ports (18a, 18b) and the first plurality of fluid flow channels; a first gasket forming a fluid seal around a periphery of the first face of the bipolar plate and the first inlet and outlet ports (18a, 18b) and forming the first inlet and outlet manifolds (15a, 15b), the first inlet and outlet manifolds each comprising an open array of raised features formed in the first gasket configured to provide a defined separation between the bipolar plate and an adjacent layer while allowing flow of fluid between the first inlet and outlet ports (18a, 18b) and the first plurality of fluid flow channels. a first plurality of fluid flow channels (13, 73) extending across a first face of the bipolar plate between first inlet and outlet ports (18a, 18b) at opposing ends of the bipolar plate; a second plurality of fluid flow channels (22, 72) extending across a second opposing face of the bipolar plate between second inlet and outlet ports (19a, 19b) at opposing ends of the bipolar plate; and a third plurality of fluid flow channels (14, 74) extending between third inlet and outlet ports (17a, 17b) at opposing ends of the bipolar plate, the third plurality of fluid flow channels provided between first and second corrugated plates (11, 12, 51, 71) forming the first and second opposing faces of the bipolar plate, wherein the first, second and third channels (72, 73, 74) are coplanar, and characterised in that the bipolar plate further comprises: first inlet and outlet manifolds (15a, 15b) across the first face of the bipolar plate providing respective fluid connections between the first inlet and outlet ports (18a, 18b) and the first plurality of fluid flow channels; a first gasket forming a fluid seal around a periphery of the first face of the bipolar plate and the first inlet and outlet ports (18a, 18b) and forming the first inlet and outlet manifolds (15a, 15b), the first inlet and outlet manifolds each comprising an open array of raised features formed in the first gasket configured to provide a defined separation between the bipolar plate and an adjacent layer while allowing flow of fluid between the first inlet and outlet ports (18a, 18b) and the first plurality of fluid flow channels. first inlet and outlet manifolds (15a, 15b) across the first face of the bipolar plate providing respective fluid connections between the first inlet and outlet ports (18a, 18b) and the first plurality of fluid flow channels; a first gasket forming a fluid seal around a periphery of the first face of the bipolar plate and the first inlet and outlet ports (18a, 18b) and forming the first inlet and outlet manifolds (15a, 15b), the first inlet and outlet manifolds each comprising an open array of raised features formed in the first gasket configured to provide a defined separation between the bipolar plate and an adjacent layer while allowing flow of fluid between the first inlet and outlet ports (18a, 18b) and the first plurality of fluid flow channels.