Project Summary
Microfluidics (lab-on-a-chip) is a promising technology for an extremely broad range of biomedical
applications including drug discovery; tissue engineering; point-of-care diagnostics; and cancer
screening based on rare cell detection, protein, DNA, or micro-RNA biomarkers, and circulating
exosomes. This proposal aims to revolutionize the biomedical microfluidic ecosystem by developing 3D
printing to routinely create very small, densely integrated microfluidic devices for the biomedical
sciences. Such devices are not possible with conventional microfluidic fabrication techniques, which
typically rely on careful alignment and bonding of a handful of individually fabricated layers, each of
which has a 2D component layout. In contrast, 3D printing permits all 3 dimensions of the device
volume to be fully utilized for component placement and channel routing, offering the opportunity for
dense component integration and small device volume. Moreover, short print times enable fast
fabrication and test cycles to dramatically speed device development. This proposal intends to initiate a
virtuous cycle in which 3D printed microfluidics becomes a disruptive tool for biomedical innovation,
which should have a substantial impact on human health.
To date, the key inhibiting factor for 3D printing has been the inability of commercial 3D printers and
resins to fabricate the requisite microvoids that comprise microfluidic structures. Our results from the
previous grant period demonstrate that with the custom 3D printer and resin formulations we have
designed and optimized, we can 3D print microfluidic devices with channels as small as 18 µm x 20
µm, valves only 150 µm in diameter, highly integrated pumps and mixers, and high density (88/mm2)
chip-to-chip interconnections containing integrated microgaskets. Moreover, we have developed a new,
inexpensive, open-source, biocompatible resin suitable for cell-based work. Aim 1 of this proposal will
focus on developing new tools for higher resolution 3D printing of microfluidic devices to generate
novel, previously unobtainable structures and properties. Aim 2 will develop devices with high
resolution porous membranes and functionalizble resin formulations. Aim 3 will develop and validate
device performance using a direct cell-based chemotactic migration assay. In short, in this proposal we
will leverage and extend our 3D printer and resin technologies to innovatively reduce fluidic feature
sizes to ~3 µm and create functionalizable, porous membranes for cell-based adhesion and migration
assays in devices with 3D geometries that are printed in 15 minutes.