Research Papers

Warpage Characterization of Microchannels Fabricated by Injection Molding

[+] Author and Article Information
Barbaros Çetin

Assistant Professor
Microfluidics & Lab-on-a-Chip Research Group,
Mechanical Engineering Department,
İhsan Doğramacı Bilkent University,
Ankara 06800, Turkey
e-mail: barbaros.cetin@bilkent.edu.tr

A. Koray Koska

Microfluidics & Lab-on-a-Chip Research Group,
Mechanical Engineering Department,
İhsan Doğramacı Bilkent University,
Ankara 06800, Turkey

Merve Erdal

Assistant Professor
Department of Mechanical Engineering,
Middle East Technical University,
Ankara 06800, Turkey
e-mail: merdal@metu.edu.tr

1Corresponding author.

Contributed by the Manufacturing Engineering Division of ASME for publication in the JOURNAL OF MICRO- AND NANO-MANUFACTURING. Manuscript received October 20, 2014; final manuscript received February 16, 2015; published online March 16, 2015. Assoc. Editor: John P. Coulter.

J. Micro Nano-Manuf 3(2), 021005 (Jun 01, 2015) (7 pages) Paper No: JMNM-14-1071; doi: 10.1115/1.4029841 History: Received October 20, 2014; Revised February 16, 2015; Online March 16, 2015

Mass-production of microfluidic devices is important for biomedical applications in which disposable devices are widely used. Injection molding is a well-known process for the production of devices on a mass scale at low-cost. In this study, the injection molding process is adapted for the fabrication of a microfluidic device with a single microchannel. To increase the product quality, high-precision mechanical machining is utilized for the manufacturing of the mold of the microfluidic device. A conventional injection molding machine is implemented in the process. Injection molding was performed at different mold temperatures. The warpage of the injected pieces was characterized by measuring the part deformation. The effect of the mold temperature on the quality of the final device was assessed in terms of the part deformation and bonding quality. From the experimental results, one-to-one correspondence between the warpage and the bonding quality of the molded pieces was observed. It was found that as the warpage of the pieces decreases, the bonding quality increases. A maximum point for the breaking pressure of the bonding and the minimum point for the warpage were found at the same mold temperature. This mold temperature was named as the optimum temperature for the designed microfluidic device. It was observed that the produced microfluidic devices at the mold temperature of 45 °C were able to withstand pressures up to 74 bar.

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Grahic Jump Location
Fig. 9

Breaking pressure of the bonding for different mold temperatures

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Fig. 8

Experimental setup

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Fig. 7

Overall part deformation

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Fig. 4

VK-X100 3D laser microscope

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Fig. 3

Photograph of the experiment

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Fig. 2

Photograph of the mold after machining

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Fig. 1

Rendered image of the CAD drawing of the mold



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