Fabrisonic, the metal 3D printing company known for its Ultrasonic Additive Manufacturing (UAM) technology, has been working in collaboration with Luna Innovations, a specialist in optical measurement technology, to develop 3D printed smart structures.
In short, these smart structures consist of metal parts printed using Fabrisonic’s UAM process which are embedded with Luna Innovations’ optic sensors. The embedded sensors, which can be installed in solid metal parts thanks to the low temperature nature of the UAM process, are capable of collecting data for various applications, including health monitoring, high fidelity control and other science and research purposes.
UAM and fiber optic sensors
The UAM process, which we looked at in some depth in an interview with Fabrisonic CEO Mark Norfolk, additively manufactures solid metal objects by layering and ultrasonically welding a series of metal foils, which are periodically machined to create the shape of the part in question. The welding itself is achieved by using high-frequency ultrasonic vibrations which are applied locally to the metal foil layers.
To embed the fiber optic sensors, channels are cut into the part during the CNC stage of the process. The fiber can then be placed into the channel and is subsequently “consolidated” into the structure with the continuation of the additive process. “The fiber,” writes Fabrisonic, “is fully integrated with the metal matrix.”
Recently, Fabrisonic and Luna were awarded two research contracts that leverage their combined smart structure manufacturing process. The contracts, awarded through the SBIR/STTR program, are in partnership with the Defense Logistics Agency and NASA. Both projects are aimed at delivering “key data from inside critical components.”
In the first contract, Fabrisonic and Luna will work alongside the Defense Logistics Agency to develop a 3D printed smart baseplate for Powder Bed Fusion (PBF) systems. In other words, Fabrisonic’s solid state metal 3D printing process will be used to produce smart baseplates for laser-based metal 3D printing systems.
The “smart” element of the 3D printed baseplates will come from the embedding of Luna’s proprietary fibers into the solid metal part. Once the baseplate is installed in a PBF machine, it will be able to collect data points, such as hundreds of strain and data points, in real time during the print process. Using Luna’s ODiSI measurement platform and the metal baseplate, the Defense Logistics Agency is seeking to gain insights into the PBF process to ultimately improve it by anticipating potential issues.
NASA’s smart pipe
The second contract will be focused on developing a smart pipe for fuel systems. This 3D printed smart pipe will integrate Luna strain sensors in its walls that will enable NASA to measure pressure, temperature and heat flux.
In this project, strain sensing fibers will be embedded into the walls of aluminum and stainless steel pipes for continuous monitoring. Once printed, the smart pipe will be sealed and cyclically pressurized during the data collection. The 3D printed pipe will provide real-time telemetry of pressure and temperatures at critical locations in the fuel system it is calibrated within.
Beyond the two recently awarded contracts, Fabrisonic and Luna are also reportedly working together to explore the potential of sensor-embedded metal prints for other demanding applications, including in nuclear reactors.