The ability to quickly and easily measure biomarker concentrations in a blood sample is an important element in bringing lab-on-a-chip devices to widespread point of care use. One challenge facing the development of these systems is sample preparation, specifically in the case of whole human blood. Because the red blood cells present in a whole blood sample can interfere with sensor operation, cell-free plasma is often desired as the analyte. However, at the point of care, the input into such a device is most often whole blood from a finger prick. Thus, a system is required which can easily extract the plasma from a whole blood sample and deliver it to the sensor. Because of the wide range of sensing mechanisms available, a versatile sample preparation and delivery system is desired. In this work, we introduce a PDMS microchannel system, produced partially through the use of 3D printing, which can be easily integrated with any flat form factor sensor platform, such as electrodes deposited on a silicon wafer. The system is passive, requiring no external actuation. The channel system is tested with both blood mimicking fluid (100% particle removal) and porcine whole blood (95% particle removal), and the ease of integration with a sensor platform is demonstrated. Such a device is a step toward the realization of widespread lab-on-a-chip deployment.