BACKGROUND:  Microfluidic devices can be used to control the movement of minute amounts of liquids. Printed circuit board (PCB) technology with modified fabrication processes has been used to allow electric connections to any points on the surface independently. Such a surface, with independently accessible, direct-referencing electrodes, would require costly integrated-circuit (IC) fabrication methods, which are not well-suited to the high surface area of microfluidic systems.

INNOVATION:  The improved microfluidic device is fabricated to have patterned electrodes on or near its surface, while the multi-layer electrical connections are underneath, allowing full independent access to each electrode. The electrodes can utilize the surface area fully, improving the efficiency of droplet manipulation mechanisms such as the electrowetting-on-dielectric (EWOD) used in digital microfluidic system. PCB technology allows the use of existing packaging options, enabling the microfluidic sections to be separately mounted and replaceable on a system board. Costs are low enough to produce disposable systems, while maintaining scalability.

POTENTIAL APPLICATIONS 

• Microfluidic devices involving droplets or bubbles, "digital microfluidics"
• Lab-on-a-chip
• Micro Total Analysis System (μTAS)

ADVANTAGES

• Enables the use of mature printed circuit board technology for microfluidics
• Simplifies system development, enables scalability, and allows separate mounting of microfluidic section, which may be disposable, on the system
• Provides unrestricted control via independent electrical access to two-dimensional surface electrode pad matrix

DEVELOPMENT-TO-DATE:  The device has been fabricated, tested, and verified.

Reference: UCLA Case No. 2006-010