Desktop micromilled microfluidics
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Micromilling is a proven method for prototyping microfluidic devices; however, high overhead costs, large machine footprints, an esoteric software stack, and nonstandard device bonding protocols may be hampering the widespread adoption of micromilling in the greater microfluidics community. This research exploits a free design-to-device software chain and uses it to explore the applicability of a new class of inexpensive, desktop micromills for fabricating microfluidic devices out of polycarbonate. We present an analysis framework for stratifying micromill’s spatial accuracy and surface quality. Utilizing this we concluded milling geometries directly on the substrate is advantageous to making molds out of the substrate, in terms of accuracy and minimum feature size. Moreover, we proposed a general procedure to calculate feedrate and spindle-speed for any sub-millimeter endmill based on a recommended load percentage. We also established stepover is the major parameter in determining the surface quality rather than spindle-speed and feedrate, showing low-cost mills are able to deliver high-quality surface finishes. Ultimately, we clarified the suitability of low-cost micromills and a cost-efficient assembly method in the field of microfluidics by demonstrating rate- and size-controlled microfluidic droplet generation.
KeywordsMicrofluidics Micromilling Low cost Microfabrication Droplet microfluidics
We like to thank Mohammadreza Rasouli from Biomat’X research laboratories at McGill University who provided a detailed pricing information on photolithography. We also like to thank Christopher Rodriguez and Sarah Nemsick for the image processing of the microfluidic droplet generation and graphic design, respectively. This work was supported by the NSF Living Computing Project Award \(\#1522074\) and NSF CAREER Award \(\#1253856\).
Supplementary material 2 (mp4 3623 KB)
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