Chaotic mixing has the ability to create complex and predictable structures. Here, we use this ability to develop a new 3D printing strategy that we refer to as 3D chaotic printing. A drop of âinkâ (i.e., a drop of a miscible liquid, fluorescent beads, or cells) is injected into a viscous and Newtonian cross-linkable liquid, and a chaotic flow is applied to generate a complex structure in just a few flow applications. This structure, which arises as a result of the rapid alignment of the injected material to the flow intrinsic skeleton (or flow manifold), is preserved with high fidelity and reproducibility by crosslinking or curing the material. This exponentially fast creation of structure (hundreds of linear meters in a few flow applications), and the accompanying rapid decrease in the length scales of the microstructure (while still preserving high resolution), is not currently achievable by any other 3D printing technique.
In particular, we explore the use of a mini-journal bearing flow and a mini-blinking vortex to implement this novel printing technique. Results from experiments and CFD simulations are used to demonstrate the robustness and reproducibility of 3D chaotic printing.
We envision diverse relevant applications for this technology, including the alignment of fibers or nanoparticles and the development of highly complex multi-lamellar and multi-component tissue structures for biomedical applications.