Bio

Crystal Owens is a distinguished postdoctoral fellow at MIT’s Computer Science and Artificial Intelligence Laboratory, in Wojciech Matusik’s Computational Design and Fabrication Lab. There, she works on improving material models and physics simulations paired with experimental data to improve material measurement. She received her Ph.D and M.S. in Mechanical Engineering at MIT where she studied rheology, or the measurement of complex fluids, applied to the additive manufacturing of flexible electronics and biocompatible microprosthetics. During her graduate studies, she developed the first 3D-printed tools for rheology, with one patented design that has allowed her to make the first measurements of a type of residual stress believed to be common within soft glassy fluids. She has also received widespread media attention for “Oreology”, the study of sandwich cookie flow and failure, as well as for LEGO-fluidics, a toy-based approach to building microfluidic networks.

Better measurement science for rheology enables a new kind of 3D printing

Technological advancements are founded on improved scientific understanding. This poster will showcase two complimentary projects tied together by rheology, or the flow of complex fluids.

In the first project (1), new tools for characterizing yield stress fluids are introduced. Existing tools to measure such fluids are highly textured, causing stress points and limited accuracy. Using topology optimization, new tools were designed as fractal webs to grasp fluid gently yet firmly, distributing stress more effectively for superior measurements. This advantage has allowed these tools to make the first measurement of previously unknown residual stress in soft gels. These tools moreover have been patented, are undergoing licensing negotiations by a major fluids manufacturer, and have been recreated by more than ten labs worldwide, showing their versatility and importance.

In the second project (2), a new type of additive manufacturing is introduced for producing flexible wires with metal-like specific conductivity. This process relies on having a solution of carbon nanotubes with proper rheology. Upon extrusion of this custom ink into a liquid bath, a precipitation reaction induces densification of the nanotubes into a solid thread. Process parameters of the printing are explored, showing tailorability of the fiber density, conductivity and specific conductivity over one, four, and five orders of magnitude, respectively. Extensibility is optionally embedded by harnessing a coiling instability during printing. This new method of printing presents a novel manufacturing platform for the production of nanomaterial-based fibers and demonstrates how ink designed with rheology control supports the development of new technologies.

1. C. E. Owens, et al. Journal of Rheology, 2020. doi.org/10.1122/1.5132340.
2. C. E. Owens, G. H. McKinley, A. J. Hart. Materials Today, 2024. doi.org/10.1016/j.mattod.2024.04.008