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Chemistry and Biochemistry Labs
Christensen Lab

3D-Printing

Active Projects

  • Developing cell-compatible devices for measuring endothelial cell chemotaxis.
  • Increasing gas transport in PEG-DA devices using superhydrophobic surfaces.
  • 3D printing porous membranes for cell-based devices

Currently Funded Grant Summaries

High-Density 3D Printed Microfluidics for Cell-Based Biomedical Applications

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 recent results 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. Initially, we will focus on developing new tools for higher resolution 3D printing of microfluidic devices to generate novel, previously unobtainable structures and properties. Next, we will develop devices with high-resolution porous membranes and functionalized resin formulations. Finally, we will develop and validate device performance using a direct cell-based chemotactic migration assay. In short, we will leverage and extend our 3D printer and resin technologies to innovatively reduce fluidic feature sizes to ~3 μm and create functionalized, porous membranes for cell-based adhesion and migration assays in devices with 3D geometries that are printed in 15 minutes.