Soft Matter Manufacturing: 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 moving 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. Jammed microgels yield at extremely low applied stresses, making them an excellent medium in which to create macroscopic structures with microscopic precision. While tracing out spatial paths with an injection tip, these granular gels yield at the point of injection and then rapidly solidify, trapping injected material in place. In this talk, we demonstrate how this physical approach to creating 3D structures negates 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 funcitonal living cell constructs and fluidic devices made from silicone. Immediate application areas include tissue engineering, flexible electronics, particle engineering, smart materials, and encapsulation technologies.