The broad objective of this research is to understand the processing science of three-dimensional microvascular networks consisting of interconnected microchannels (1-300 mm). The experimental approach is to fabricate these networks by robotically controlled deposition (RCD) of new fugitive organic inks. The proposed RCD route relies on a layer-by-layer deposition of fugitive nanocomposite organic inks to create three-dimensional fluid paths. It is a mold-less deposition process in which a freestanding scaffold of the network is formed first, followed by infiltration of a secondary (structural) matrix phase and removal of the sacrificial scaffold. This research will focus on the design and characterization of nanocomposite organic inks for use in RCD of three-dimensional freestanding scaffold structures, as well as process models that track the time-dependent deformation of the scaffold network from deposition through final curing of the secondary matrix. The effects of nanocomposite ink composition and rheology as well as various process parameters (e.g., nozzle diameter, deposition speed, extrusion pressure) on shape evolution during fabrication will be studied. Finally, the mixing performance of fabricated 3-D microvascular fluidic devices will be evaluated for a variety of architectures and flow conditions.
The proposed research is expected to provide fundamental knowledge needed for agile fabrication of microfluidic networks. Three-dimensional microvascular networks will provide an enabling platform for a new generation of microfluidic devices in biomedicine for applications such as gene sequencing, functional genomics, drug discovery, pharmacogenomics, diagnostics, and pathogen detection/ID. Training will be provided for one graduate student throughout the project period educated in an interdisciplinary research group at the University of Illinois that facilitates interactions across a number of disciplinary fields.