Leveraging Jammed Microgels to Shape Complex Fluids: One Method for 3D Printing with Cells, Gels, Elastomers, and Colloids


3D printing is generally a race against instabilities; the challenge is to prevent printed liquid features from flowing or breaking up once deposited. Printing directly into a support material made from jammed granular-scale gel particles mitigates the two nearly ubiquitous sources of instability encountered in 3D printing: surface tension and body forces. The yield stress of these jammed microgels can be tuned over a broad range, making them excellent media in which to create macroscopic structures with microscopic precision. While tracing out spatial paths with a printing nozzle, the microgels yield near the point of material deposition and then rapidly re-solidify, trapping injected material in place. In this talk, we demonstrate how the rheological properties of microgels enable this physical approach to creating 3D structures, negating the effects of surface tension and gravity, allowing a wide breadth of materials to be structured. With this method we create complex 3D objects made from silicones, hydrogels, colloids, and living cells, including functional living cell constructs and fluidic devices made from silicone. Immediate application areas include tissue engineering, flexible electronics, particle engineering, smart materials, and encapsulation technologies.

Date: 2020-07-09, 14:00 - 15:00 (EDT UTC-04)
Language: English
Trainer: Dr. Thomas E. Angelini

Dr. Thomas E. Angelini is an associate professor in the department of Mechanical and Aerospace Engineering at the University of Florida. In 2005, Dr. Angelini received his PhD in physics from the University of Illinois, studying self-assembly of proteins, lipids, DNA and viruses, using techniques like small angle x-ray scattering (SAXS), cryo-electron microscopy, and confocal microscopy. During his postdoc at Harvard University, he moved into the field of cell mechanics, studying collective cell migration and force transmission in cell monolayers using time-lapse microscopy and digital image analysis. He also began work on bacterial biofilm growth and spreading, focusing on the forces generated by the biosurfactants and extracellular polysaccharides that bacteria excrete. In 2010, he became an assistant professor at the University of Florida, where he works on cell-assembly and collective motion in 2D and 3D cell populations, 3D bioprinting and soft matter manufacturing, and lubrication of soft interfaces. In 2014, Dr. Angelini received the NSF CAREER award to study the stability and dynamics of tissue cell assemblies embedded in yield stress materials. In July, 2015 he was granted tenure at the University of Florida.