NER: Flow Control Networks for Nanoscale Biofluidics

0103076李本提案是对NSE，NSF-0019的回应。 随着微加工生化仪器领域的不断发展，越来越复杂的设备是必要的。 当前绝大多数微流体装置中的流体流动是电驱动的，特别是对于那些涉及生物分子如DNA、RNA和蛋白质的基于电荷的分离的微流体装置。 与微机械压力驱动泵相比，这种电驱动流提供了许多优点，包括易于制造和操作、与其他功能元件集成的简单性以及不存在移动部件。 然而，这种电泵送装置的缺点是缺乏对多个互连通道中的流体流动的同时控制，并且不能对流速和方向进行空间或时间控制的修改。真正的芯片实验室技术的实现，其中桌面生物分析工具的能力在信用卡大小的包装中被复制，将需要在混合器、反应器、储存器、分离器、传感器和相关部件之间的互连微流体通道的复杂网络中进行精确的流量控制和计量。 为此，我们建议以这种小型化的形式创建用于流体控制的集成系统。 一种新颖的微流体元件，微流体多路复用器，可以克服上述普通电驱动流体流动的限制。 这是通过施加径向外部电场直接控制微流体通道内表面的电特性来实现的。 微流体多路复用器允许在复杂的微流体网络中进行设备上的流量控制，将作为一系列微制造设备的关键组件，用于执行独特的生物分离和生物分析。

0103076LeeThis proposal was received in response to NSE, NSF-0019. As the area of microfabricated biochemical instrumentation continues to grow, increasingly sophisticated devices are necessary. Fluid flows in the great majority of current microfluidic devices are electrically driven, especially for those involved in charge-based separations of biological molecules such as DNA, RNA, and proteins. This electrically driven flow offers numerous advantages over micromachined pressure-driven pumps, including ease of fabrication and operation, simplicity of integration with other functional elements, and the absence of moving parts. However, this electrical means of pumping suffers from the lack of simultaneous control over fluid flow in multiple interconnected channels, and the inability to perform spatial- or time-controlled modification of flow rate and direction.The realization of true lab-on-a-chip technology, in which the capability of desktop bioanalytical tools is replicated in a credit card sized package, will require precise flow control and metering in complex networks of interconnected microfluidic channels between mixers, reactors, reservoirs, separators, sensors, and related components. To this end, we propose to create an integrated system for fluid control in this miniaturized format. A novel microfluidic element, a microfluidic multiplexer, can overcome the limitations mentioned above for ordinary electrically driven fluid flow. This is accomplished by directly controlling the electrical properties at the inner surface of the microfluidic channels through the application of a radial, external electric field. The microfluidic multiplexer, which allows on-device flow control in complex microfluidic networks, will serve as the key component in a range of microfabricated devices for performing unique bioseparations and bioanalyses.