NER: Flow Control Networks for Nanoscale Biofluidics

0103076 lee该提案是在NSE， NSF-0019的响应中收到的。随着微型生化仪器领域的不断发展，越来越复杂的设备是必要的。目前绝大多数微流控装置的流体流动都是电驱动的，特别是那些涉及生物分子（如DNA、RNA和蛋白质）的电荷分离的装置。与微机械压力驱动泵相比，这种电驱动流具有许多优点，包括易于制造和操作，与其他功能元件集成简单，并且没有运动部件。然而，这种电动泵送方式的缺点是无法同时控制多个相互连接的通道中的流体流动，并且无法对流量和方向进行空间或时间控制。要实现真正的芯片实验室技术，将台式生物分析工具的功能复制到信用卡大小的封装中，将需要在混合器、反应器、储存器、分离器、传感器和相关组件之间相互连接的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，我们建议在这种小型化的格式中创建一个集成的流体控制系统。一种新型微流控元件，微流控多路复用器，可以克服上述普通电驱动流体流动的限制。这是通过应用径向外电场直接控制微流体通道内表面的电学特性来实现的。微流控多路复用器允许在复杂的微流控网络中进行设备流量控制，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.