Patent Issued for Navy’s 3D Printing Material for Marine-Biodegradable Sensors and Robotics

Equipment like autonomous or unmanned underwater vehicles (UUVs) can help researchers get a closer look at under-the-sea environments that they are unable to easily traverse themselves. UUVs are used for a variety of applications, such as mapping, observation and research, and archaeological expeditions, but what happens to this equipment once their task has been completed?

Some of these UUV solutions that deploy oceanic sensors only last a set amount of time before they stop working, or were built for single-use only. As a result, unfortunately, they’re often abandoned on the ocean floor, as retrieval can get pretty expensive. Obviously, this is not the best solution for our planet, but U.S. Navy scientists are working to turn this around.

Josh Kogot, Ryan Kincer, and April Hirsch work at the Biotechnology Research and Development Lab in Panama City, Florida’s Naval Surface Warfare Center, and have invented a new material that could be used to make underwater equipment biodegradable. The team just announced that they’ve been issued a 20-year patent for this new 3D printing material, made of a marine-biodegradable base polymer that will break down over time, making UUVs safer to dispose of underwater.

Illustrates an exemplary 3D printing method for producing a marine biodegradable structure with a selected rate of degradation in the marine environment.

The patent description states, “Faster rates of degradation of the structure are obtained with larger proportions of gelling agent in the composition. The composition may also include biological materials to further promote or control the biodegradation of the structure, and other additives such as nutrients for microorganisms or solidifying agents. 3-D printing of the material occurs at relatively lower temperatures to avoid damage to the biological materials.”

This sounds sort of like PHAbulous Filaments, which could supposedly be used make 3D prints that would biodegrade in your backyard within two months.

To make this 3D printable material, the team adjusts a combination of polymers, such as polybutylene succinate (PBS), polycaprolactone (PCL), and polyhydroxyalkanoate (PHA), and adds a gelling agent, often the indigestible polysaccharide agar, to the mix. This means that objects and structures printed out of the material, such as sensors and UUVs, can, as the patent states, “achieve a desired rate of degradation.” Just like 3D printed implants made out of biodegradable materials can break down over time in the human body, this new material will last for a certain amount of time before it safely degrades.

(Above: Illustrates an exemplary carrier vehicle constructed by 3D printing using the marine biodegradable material of the present invention.)

The patent goes on to say, “There is currently no known way to design and produce these structures so that their rate of degradation can be controlled. There is an unmet need to produce marine biodegradable 3D printable structures for which the rate of degradation of each structure can be selected for a particular mission.”

Additionally, the researchers also used biological materials, such as a synthetic hagfish slime invented by the same lab, in the design to give microorganisms or enzymes something on which to feed. This is how the biodegradable polymers that make up the carrier vehicle structure are degraded over time.

“When these biological materials are incorporated into the composition, the extrusion occurs at relatively low temperatures to avoid harming the microorganisms or other biologicals,” the patent continues. “In yet another embodiment, additional additives may be included in the composition, such as nutrients to support the growth and activity of microorganisms, antibiotics for microorganism growth selection or growth deterrence, or certain solidifying agents.”

Synthetic hagfish slime (Image courtesy of US Navy)

The Department of Defense’s national partnership intermediary for technology transfer, TechLink, is offering free licensing services to businesses for this new biodegradable 3D printing material technology.

“Not only can you 3D print this material into just about anything, but to finely control the rate at which it degrades is really useful. This technology has the potential to cut costs and benefit the environment, it could have many military and commercial applications for all types of underwater equipment,” explained Brian Metzger, a senior technology manager at TechLink working with Panama City’s Navy tech transfer team to assist private companies in commercializing these Navy inventions.

Metzger says that the potential applications for this new biodegradable material go beyond UUVs—the sky’s the limit, but the patent needs to be licensed before commercialization can occur.

Drs. Josh Kogot, Michelle Kincer, and Ryan Kincer at the Naval Surface Warfare Center in Panama City show the synthetic hagfish slime they developed in 2016 (Image courtesy of Ron Newsome/US Navy)

(Source: TechLink)