Development of an injection molding tool for complex microfluidic geometries

• Published in: Microsystem technologies : sensors, actuators, systems integration Vol. 17; no. 9; pp. 1537 - 1540
• Main Authors: Geiger, Emil J., Mair, Dieudonne A., Svec, Frank, Pisano, Albert P.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-09-2011; Springer
• Subjects: Applied fluid mechanics; Applied sciences; Electronics and Microelectronics; Engineering; Exact sciences and technology; Fluid dynamics; Fluidics; Fundamental areas of phenomenology (including applications); Instrumentation; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Machinery and processing; Mechanical Engineering; Mechanical instruments, equipment and techniques; Micromechanical devices and systems; Moulding; Nanotechnology; Physics; Plastics; Polymer industry, paints, wood; Technical Paper; Technology of polymers; Mold Design; Injection Molding Process; Mold Insert; Mold; Injection Molding; Thickness; Design process; Injection molding; Filling; Shrinkage; Capillary tube; Microfluidics; Fluidics
• ISSN: 0946-7076; 1432-1858
• DOI: 10.1007/s00542-011-1323-x

This paper will track the design and results of an injection molding tool developed to manufacture microfluidic chips. The mold design and injection molding process was complicated by the presence of integrated capillary fluidic interconnects. We determined that design of the runner and gate system responsible for delivering molten plastic to the cavity had a significant impact on the quality of parts produced by the mold and the size of the process window. Numerical results confirm our findings that reducing gate lengths and increasing part thickness dramatically improved the filling profile and lowered injection pressures by 37%. Finally, the influence of gate location on part shrinkage is analyzed and discussed.