A microfabricated fluidic unidirectional valve includes a microfabricated elastomer material having a flow through channel. The microfabricated fluidic unidirectional valve also includes an elastomer flap attached to the elastomer material in the flow through channel. The elastomer flap forms a seal in the flow through channel to prevent fluid from flowing in a first direction through the flow through channel and to allow fluid flow in a second direction through the flow through channel.