The goal of this project is to develop a passive flow control paradigm for microfluidic devices, which will reduce the need for external (off-chip) hardware and facilitate the development of widely distributable hand-held bioanalytical devices. The proposed approach for flow control is compatible with existing microfluidic analytical systems (in particular, microfluidic integrated genomic analysis chips), and represents a significant step towards miniaturization of instrumentation for point-of-care testing. The proposed study will quantify the mechanical performance requirements that ensure bioanalytical functionality of a proven genomic analysis microchip, while simultaneously developing passive deformable features that can be used in lieu of active valves at channel intersections. The central hypothesis is that flow can be directed into different branches of a microfluidic network by changing the time-dependent excitation of a single actuator, by embedding deformable passive features modulate the dynamic responses of the different branches. These features (which act as fluidic inductors, capacitors and diodes) significantly reduce actuation requirements - thus enabling new actuation strategies that avoid off-chip pressure sources and switching solenoids. The proposed approach is particularly well suited to genomic analysis microchips, which require only several fluidic domains with very few valves. On-chip flow control would dramatically decrease their cost and increase their portability, ultimately placing genomic analysis directly in the hands of physicians who monitor epidemic outbreaks or surgeons conducting lumpectomies. We propose an integrated study that explicitly determines flow conditions that maintain analytical functionality, while simultaneously developing passive features and fluidic networks to achieve these conditions.
Microfluidic devices offer a promising pathway to create new types of inexpensive, highly portable tools for rapid point-of-care diagnostics. Such devices could place rapid genomic analysis directly in the hands of physicians who monitor epidemic outbreaks in remote locations, or surgeons needing rapid biopsies. We propose to develop a new approach to control fluid flow in microfluidic devices that reduces or eliminates the need for off-chip hardware, facilitating the development of hand-held diagnostic tools. A microfluidic integrated genomic analysis microchip will be used to quantify the required flow characteristics that maintain analytic functionality, while simultaneously optimizing passive deformable features that lead to acceptable flow conditions. While demonstrated here for pathogen detection, simple but effective flow control in integrated microfluidic devices has widespread application to diagnostics in general.
