Packaging and Assembling Microfluidic Devices via Plastic Injection Molding

A silicon based microfluidic device has been assembled, encapsulated, and packaged with fluidic and electrical interconnects via plastic injection molding. A microbubble generator was chosen as the test piece for this packaging scheme. It consists of a straight channel etched in silicon and a Pyrex® cover. Gold traces on the Pyrex® allowed for bubbles to be generated by either electrolysis or boiling. The device was subsequently loose assembled in an injection mold with fluidic headers and electrical leadframes. Plastic (Topas® COC) was injected into the mold to assemble, encapsulate, and package the device. With proper design the device routinely survived the injection molding event. The final package demonstrated electrical continuity and shows promise for fluidic integrity. This packaging technique could easily be extended to a wide variety of devices (valves, pumps, mixers, etc) allowing for a system to be developed at the board level from discrete devices.