HIGH PRESSURE MONOLITH ELECTROOSMOTIC PUMP

The objective of lab-on-chip (LOC) is to integrate and perform multiple analytical processes on a microchip platform. So far, most LOC research has been focused on electrophoretic separations. Limited progress has been made on multi-process integration, due mainly to the lack of a robust and miniaturized pump that can deliver constant flow and be integrated with LOC devices. Microchip HPLC can and will play an important role in point-of- care measurements, remote sensing and chemical and biological warfare agent detections. Highly parallel configurtaions can enhance the sample throughput considerably with commensurate impact on drug screening and biomarker discovery. A major challenge toward microchip HPLC is the lack of a robust and miniature high-pressure pump that can be integrated with LOC devices. The goal of this project is to address this issue. Under the support of the DOE STTR Phase I and initial Phase II (SC0006351), we have demonstrated the feasibility of an innovative open-channel electroosmotic pump (EOP). The pump worked like a voltage power supply, and therefore we termed it a Pressure Power Supply (PPS). A single PPS may produce only a moderate pressure, but, when a number of PPS were connected in series, a very high pressure could be produced. In the STTR Phase I project, we demonstrated that the pressure output was directly proportional to the number of PPS serially- stacked. Theoretically, we could produce any (high) pressure as long as we connected adequate number of PPS in series. In practice, the upper pressure was limited by the accessories such as tubing connectors, unions, etc. In the initial Phase II project, we developed a prototype open- channel EOP and utilized it for HPLC separations of various biomolecules. During this work, we encountered a challenge in derivatizing the interior surfaces of narrow capillaries/channels. In this sequential Phase II project, we will develop a new chemical approach to address this issue. We will develop two prototype (miniaturized HPLC or mHPLC) instruments that will integrate the new EOP, on-chip smaple injection scheme, and a capillary seperation column. We will then couple the mHPLC with a mass spectrometer for proteomic analysis. Commercial Applications and Other Benefits: The mHPLC will have many other applications. Because of its compact size and light weight, it can be used in future Spacelab in the search for extraterrestrial life. It can be used for remote and battlefield Chemical and Biological Warfare Agent detection, since it can easily be carried by a person in a backpack. It can be highly parallelized to increase the throughput for drug compound screening. It can be used for bed-side clinical analysis.