Despite their promise to enable high-throughput science and discovery, microfluidic devices have not yet been broadly adopted. An important missing element in current microfluidic technology is a simple way to interface a large number of fluidic and pneumatic lines to devices. We have developed both a reusable manifold strategy and a fluidic reservoir system that enable rapid world-to-chip connectivity. We demonstrated the wide applicability of these tools by interfacing with a 51-inlet microfluidic chip containing hundreds of embedded pneumatic valves. Due to the speed of connectivity, these advances are ideal for rapid prototyping and are well suited to serve as "universal" interfaces, which together facilitate the application of microfluidics to highly multiplexed experiments.
Microfluidic devices with many fluidic and pneumatic inlets are difficult to connect to benchtop reservoirs and controllers. Many hours can be spent sorting, untangling, and connecting tubing to a single device. If one then finds that the device is not fully functional, the process must begin again on a new device. Fluid flow into microfluidic devices is typically controlled by either syringe pumps (expensive and big) or pressurized vials (cheap but difficult to handle). The designed devices are intended to simplify and speed up the connection of complex microfluidic devices to benchtop fluid reservoirs and pneumatic valve controllers. Ideally, our technologies will make high-throughput microfluidic systems more accessible to laboratories interested in utilizing microfluidics for high-throughput chemical and biological studies.
Create an improved method to interface a large number of fluidic inlets and pneumatic control lines with microfluidic devices. Reduce the cost and difficulty of controlling many different fluids on a chip.
The concept driving our macro-to-micro interface scheme involves a network of vacuum channels that holds a microfluidic device against a rigid manifold such that fluid can be injected through the manifold and into the device without leakage (Fig 1). We fabricated a PMMA manifold with a vacuum annulus milled around each inlet port. Each port is permanently connected at the back of the manifold to fluid reservoirs and pneumatic controllers.
Fluidic reservoirs holding 5-mL volumes (much more than is used in a microfluidics experiment) are sealed inside a canister half filled with water, which allows the vials to float. Pressurizing the canister pushes fluid out through needles in the lid. Because the reservoirs float, constant flow rate is maintained even when fluid is drained from reservoirs at different rates.