The concept of lab-on-chip is created with an objective to integrate and perform multiple analytical processes (e.g. sample pretreatment, solution distribution/mixing, separation, detection, etc.) on a microchip platform. So far, most of lab-on-chip research is focused on electrophoretic separations, and relatively much less work is carried out on multi-process integration. One of the main reasons for limited process integration is the lack of a robust and miniaturized pump that is readily integrated with lab-on-chip devices. Microchip HPLC is envisioned to play an important role in point-of-care (POC) measurements and Chemical and Biological Warfare Agent (CBWA) detections. It can be highly parallelized to increase sample throughput (e.g. for drug compound screening), which will have great impact on drug screening and biomarker discovery. Microchip HPLC combined with mass spectrometer could accelerate the proteomic research and reduce its cost considerably. A major challenge toward microchip HPLC is the lack of a robust and miniaturized high-pressure pump that is integrateable with lab-on-chip devices. In availability of reliable on-chip sample injection valves is another obstacle toward these applications. We propose to develop a cascade open-channel EO pump and an on-chip sample injection valve to address these issues. The cascade pump will consist of alternately-arranged """"""""+"""""""" and """"""""-"""""""" pumps. This pump will be able to generate flow rates of up to 5L/min and pressures of up to 1000 psi for microchip HPLC applications. We will develop a bubbleless electrode to solve the electric connection problems. The electrode will be capable of applying high voltages onto EO pumps while preventing pump solutions from leaking out. In addition, it will minimize the pump solution composition change and eliminate bubble formation due to electrolysis. We will also develop an on-chip sample injection valve for microchip HPLC separations. The valve will have an injection volume ranging from sub-nL to 5L, and the injected volume will be reproducible. All these function-different components will be integrateable with lab-on-chip devices.
We will develop a microchip platform that integrates a cascade open-channel EO pump, an on-chip sample injection valve, a monolith separation column and an on-chip detection scheme to perform HPLC. The cascade pump will consist of alternately-arranged """"""""+"""""""" and """"""""-"""""""" pumps to generate flow rates of up to 1 5L/min and pressures of up to 1000 psi for microchip HPLC applications. We will develop a bubbleless electrode capable of applying high voltages onto EO pumps while preventing pump solutions from leaking out, and eliminating bubble formation due to electrolysis.
