A New Method to Construct Bio-inspired 3-D Microvascular Networks in Plastic Substrates
J.-H. Huang, J. Kim, A. Jayaraman, V.M. Ugaz
Texas A&M University, US
Keywords: microvascular networks, microfabrication, tissue engineering
Abstract:A number of approaches have been investigated to construct 3-D microfluidic networks, but many of these methods involve time-consuming serial processes that are not practical for mass production and are generally optimally suited for a relatively narrow range of feature sizes. Here we describe a new process that enables 3-D branched microvascular networks to be constructed in a single step. This technique employs an electrostatic discharge phenomenon that occurs when a dielectric medium is energized by a strong electric field and subsequently discharged to form branched “tree-like” channels in polymer substrates. Suitable space charge distributions are generated by irradiating the sample with an electron beam so that the energy released upon discharge is sufficient to locally vaporize and fracture the material, leaving behind a network of branched channels in a tree-like fractal structure. The beam intensity and spatial irradiation profile can be adjusted to control the location and morphology of the discharge structures. The embedded patterns exhibit a self-similar fractal network structure, with channel characteristic dimensions ranging from approximately 10 µm to 1 mm in diameter. Interconnected networks with multiple fluidic access points can be straightforwardly constructed. Quantification of the network branching characteristics reveals remarkable similarity to naturally occurring vasculature.