Microfluidic Interfaces

Overview

The chip-to-world interface is a classic problem in microfluidics that is largely related to the disparity in volumes that can be conveniently handled in chips versus that in the fluidic system interfaced with the chip. We take the broader view that this interface also includes issues such as reagent loading or packaging, chip installation and setup, as well as controller and user interface. It is our belief that a simple, standardized, and robust interface will greatly increase the accessibility and usefulness of microfluidics to non-experts.

Results

Standardized connectors for PDMS chips

We have developed a standardized connector for PDMS chips with a number of advantages:

• Connection of 16 tubes to the chip simultaneously
• Stablized connection by mechanical linkage of multiple tubes. This has been especially useful in low-friction and/or brittle polymer chips including PFPE.
• Increased design efficiency with standardized footprint of ports
• Rapid, simultaneously loading of reagents into 16 tubes prior to connection to the chip. Reagents or valve-control fluid can be aspirated from a standard 1536 well plate.

Reliable delivery of small volumes from reservoirs to chips via tubing

In numerous applications, it is necessary to deliver a sample or reagents at the last minute to a chip. Examples include assays or reactions involving volatile or unstable precursors and reagents. We have developed a semi-automated system for transferring samples into PDMS chip, emphasizing low loss of sample/reagent and the ability to handle very small volumes of reagents (i.e., 100s of nL). The rapid phase of loading takes place off-chip while a slower, but more accurate phase (to avoid loss) takes place on-chip using valves or specialized channel geometries.

Team Members

Former:

• Dirk Williams (staff machinist)
• Hui-jiang Ding (research staff)
• Kan Liu (collaborator from Clifton Shen lab)
• Chiyun Xia (postdoctoral scholar)
• Yuliang Deng (graduate exchange student