Current vat photopolymerization additive manufacturing (AM) processes require extensive efforts to formulate resins that are suitable for the light source and to match the refractive indices of any additive to that of the resin. In some cases, the use of UV-based polymerization may not be compatible or may require complex formulations. To overcome these challenges, ultrasound could be utilized to initiate and control polymerization in the vat rather than light (or heat).
This novel AM approach utilizes cavitation bubbles generated within liquid resin by ultrasonic energy that trigger, induce, or catalyze a polymerization process (3D Ultrasound Polymerization). Ultrasound may be generated by piezoelectric transducers or high-power lasers and by modulating the ultrasound wave (frequency and amplitude), the cavitation site could be directed.
- Faster polymerization process -> higher throughput
- Simpler resin formulations -> method does not require photo or thermal initiators
- Broad range of feedstock materials (i.e. dark, opaque, cloudy solutions) -> unlike light-based AM, this ultrasound AM method does not require optically transparent resin or additives; method is agnostic to refractive index of light
- Can complement existing AM processes
- May also enable microencapsulation -> alternative to UV curing or heat chamber
- 3D printing of non-transparent glass, ceramics, and other composites.
- Microencapsulation to form composite materials
Current stage of technology development: TRL 3
LLNL has filed for patent protection on this invention.
US Patent Application No. 20230249397 SYSTEM AND METHOD FOR ULTRASOUND-INDUCED ADDITIVE MANUFACTURING OF POLYMERS AND COMPOSITES published 8/10/2023