I discuss using bulk and interfacial jamming of colloidal particles to 3D print soft materials. In the interfacial case, nanoparticle surfactants (NPS) are assembled at the oil-water interface and then jammed into a rigid structure by surface tension. The NPS assembly possesses enormous mechanical anisotropy and bending moduli that can be tuned over 7 orders of magnitude, from sub-kBT to 106 kBT. The solid-like interface allows Newtonian liquids, i.e., water and oil, to be printed into fibrillar structures with applications in reconfigurable fluidics and active matter. I then cover the case of printing a liquid into a granular support bath, in which free-hanging, fractal, vascular networks can be produced. The necessary Herschel-Bulkley support bath rheology is derived from a purely physical mechanism (granular jamming), allowing for effectively arbitrary chemical composition. This in turn enables us to model the extracellular matrix with high chemical and rheological fidelity, allowing for complex co-cultures of mammalian cells. I discuss the effects of tuning particle rigidity (from 10 – 104 Pa) upon the rheology of the granular suspension and its effect on print resolution. Finally, I demonstrate an application in the form of a perfusable blood-brain barrier model for drug development studies.

3D printed water – harnessing the jamming transition to make reconfigurable materials and organs-on-a-chip

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.