Tham khảo tài liệu 'bio-mems technologies and applications - wang and soper (eds) part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 270 BioMEMS Technologies and Applications electrochemical detection and the high-voltage power supply for controlling electrophoresis. A battery-powered potentiostat was used to isolate the interfering separation current allowing the ECD of cotechol and dopomine. The combined system was an amazing 4 in. X 6 in. X 1 in. and weighed only 350 g. A third example of miniaturizing the instrumentation for microchip CE-ECD was published by Garcia and In this work a simple 3-channel power supply with integrated analog controls was constructed. The power supply could be operated in any of the three standard injection modes gated pinched or hydrodynamic. The system could operate from either battery or AC power sources and had a battery lifetime of two hours for continuous operation. The final example of a miniaturized integrated microchip CE-ECD system was published by Jiang and In their example a miniaturized potentiostat was produced that fit in a card that was X cm. A high-voltage power supply was also generated that could produce up to 4000 V and perform either gated or pinched injection. Electrode Configurations The second key element in developing an effective electrochemical detector is the interface between the microchip and the electrode. To date there have been two popular methods for coupling which we will refer to here as off-chip detection and microfabricated electrodes. In the off-chip electrode configuration the electrodes are separate from but aligned to the microchip. With microfabricated electrodes the electrodes are produced using micromachining techniques and are contained on the same microchip as the electrophoresis system. Finally there has been recent interest in the development of other electrode configurations that integrate electrodes as part of the microchip but do not use micromachining methods for construction. This section will present the major types of electrode configurations and their advantages and .
