A microfabricated cross flow filter may have multiple filtration stages. The filtration stages may include microfabricated filter barriers and gaps created in a substrate, thereby allowing very tight tolerances in the filter barrier and gap dimensions to be maintained. Using the microfabrication techniques, the filter barriers can be made having arbitrary shapes, and arranged at an angle or curved with respect to the flow direction, making the pressure drop across the filtration stage more uniform in the cross flow direction.