Continuous passive separation based on laminar flow and creative geometries has advantages over traditional separation methods such as dielectrophoresis, hydrodynamic chromatography, and acoustic separations to name a few. One advantage in particular is the lack of constant energy supply needed and another advantage is the ability to continuously operate the device for larger sample volumes without much interruption. Adding external forces to a device also can increase its complexity and may limit an ability to function on biological samples. In this paper we demonstrate a passive separation device.