Support Medium for 3D Printing Silicone Structures with Fine Features

Ultra-Low Interfacial Tension Material Enables High-Precision Silicone 3D Printing

This 3D printing support material allows for liquid ink-printed silicone structures to have features as small as 8 microns. Silicone is a highly useful material due to its high thermal stability and resistance to weathering, ozone, moisture, and UV radiation. However, soft silicone remains a challenging material to use in additive manufacturing or 3D printing. The most effective support medium available for 3D printing liquid silicone consists of hydrocarbon-based jammed microgels, but these microgels are difficult to formulate. Additionally, the destabilizing interfacial forces between the silicone ink and the microgels in the support medium can lead to the disintegration of more intricate details on the printed silicone structure over time.

Researchers at the University of Florida have developed a 3D medium that uses droplets of water and glycerol emulsified in silicone oil to support silicone prints with ultra-low interfacial tension. The support medium enables silicone 3D prints with smaller, more intricate features, which have applications for personalized implants, lab-on-a-chip devices, tissue/organ-on-a-chip devices, point-of-care devices, biological machines, and other medical devices.

Application

Emulsion-based support material that facilitates 3D printing silicone structures that have finer details

Advantages

• Emulsion droplet size can be easily controlled, enabling more precise 3D printing than with jammed hydrocarbon microgels, where particle size is harder to control.
• Ultra-low interfacial tension prevents breakup of small, intricate features, supporting 3D printed silicone structures with custom features as small as 8 microns
• Emulsion formulates easily with a wide range of tunable material properties, adapting to suit different soft material liquid inks
• Support medium is optically clear, allowing full visibility during printing

Technology

The support material is a packed inverse emulsion in which emulsion droplets containing a mixture of water and glycerol are the dispersed phase, and silicone oil is the continuous phase. The relative proportions of water and glycerol match how fast light travels through the silicone oil, thus making the material optically clear. The mixture of water, glycerol, and silicone oil can have a wide range of different material properties that are easier to tune than those of hydrocarbon-based microgels. Using silicone oil as the continuous phase creates an environment that has ultra-low interfacial tension with deposited silicone-based inks. This prevents the breakup of small printed features, enabling constructs to have features as small as 8 microns in diameter, which is 10 times finer than previously achieved with hydrocarbon-based microgel support systems.