Conventional manufacturing method for silicone-based products is injection molding, which limits the complexity of their designs; additive manufacturing (AM), however, is able to achieve more intricate geometries. Presently, state-of-the-art silicone formulations for photocuring typically involve either incorporating a photo-protected Pt catalyst with reduced filler concentration or necessitate modifying silicone resin by introducing photocurable functional groups (such as acrylates or thiol-ene functionalities). Unfortunately, these alterations to the resin, while enabling AM, often result in compromised properties. To achieve high-performance photocurable silicones, a more straightforward approach is needed to enable 3D printing using unmodified readily available silicones that employ traditional Pt-catalyzed hydrosilylation chemistry for curing.
LLNL researchers have developed a novel photocurable silicone useful for producing three-dimensional objects via additive manufacturing. The resin formulations consist of a mult-component siloxane polymers with different functionalities, a platinum catalyst, a photoinitiator, and other organic peroxides. The LLNL invention involves controlling the spatial and temporal aspects of the hydrosilylation reaction of silicones via the incorporation of additives which accelerate the photooxidation of photocuring silicones. This increase in reaction rate is crucial for additive manufacturing, enabling curing of a layer within 1 minute. Additionally, the resin formulation enhances the shelf life of silicone resins through novel addition of specific functionalities to the silicone polymers. The shelf life of the silicone resin can be extended from 6 hours to 1 week. The formulation is potentially suitable for stereolithography, two photon lithography, volumetric additive manufacturing and UV-coating applications.
Related technology also available for licensing: Novel siloxane formulations and methods for 3D printable silicones inks used in direct ink writing (DIW)
Current stage of technology development: TRL-3
LLNL has filed for patent protection on this invention.
- Increased photocuring reaction rate enabling curing of a layer within 1 minute.
- The shelf life of the silicone resin can be extended from 6 hours to 1 week.
- The formulation is potentially suitable for stereolithography, two photon lithography, volumetric additive manufacturing and UV-coating applications.
The 3D printing of silicones has helped with the rapid development, prototyping and manufacturing of new emergency medical devices. It can also be beneficial towards manufacturing for surgical guides, medical instruments, and other implants, including dental devices and hearing aids.
