3D Printing: Prototyping to Protect the Ocean
Additive manufacturing technology is right now being utilized in the early testing and latter molding for SeaTags that hope to change scientists' understanding of the ocean, and to better protect the life within.
Desert Star Systems, based in Northern California and acclaimed for their advances in underwater technology, began prototyping tags for sea animals using additive manufacturing. Their latest line, SeaTag animal tags, has significantly advanced animal tagging and tracking technology. Their advanced tags can dive deeper, survive longer, and withstand more environmental abuse than any previous models.
With the use of 3D printed prototypes, Desert Star designed animal specific SeaTags -- tags that conform more precisely to the animals they are applied upon. Whether by slimness, lightness, or shape, SeaTags are making tracking more reliable for researchers and less cumbersome for the animal.
SeaTags are used by researchers to learn details about how creatures of the sea interact with protected and highly fished areas of the ocean. The tags are able to estimate animal locations around the world. They can detail the temperature of the water, depth of the animal, animal behavior through acceleration measurements and in the future oxygen levels in the water, water salinity, and even oil dispersants. The information is then used to better protect the ocean's ecosystem by protecting the creatures that inhabit it every day. The tags revolutionize sea animal tracking.
"Our goal is to develop very specific sizes and shapes of animal tags-such as an incredibly low-drag miniature turtle tag. 3D printing with ZoomRP.com allows us to make very odd and very unique shapes that we would otherwise need injection molding to make," explained Thomas Gray of Desert Star Systems. "These satellite tags will locate animals on a daily basis using the Argos satellite system while causing very little impact on the animal itself as related to larger satellite transmitters."
Rather than creating highly expensive tools for single molds of prototypes, Desert Star sent in 3D CAD files in the form of .STL files to ZoomRP, which is part of Solid Concepts. The files were blueprints for prototypes of shark fin tags, marlin tags, dolphin tags, and sea otter tags. Desert Star experimented with PolyJet, Stereolithography (SLA), Selective Laser Sintering (SLS), and Fused Deposition Modeling (FDM). PolyJet and SLA are photocurable processes. The resolutions (or layer thicknesses) of PolyJet (at 0.6mm by 1.7mm) and SLA (at 5mm by 20mm) made it feasible for Desert Star to 3D Print smooth and complex molds for tags. The molds were filled with polyurethanes and then assembled by Desert Star. SLS, a sintering process involving powdered nylon, and FDM, a thermoplastic extrusion process, are used for prototypes that endure form, fit, and function and end-use implementation. SLS was implemented during the testing of the SeaTag used on the tiger shark pictured here. With 1/3rd of pelagic sharks slowly disappearing, learning more about the ocean, its life forms, and how they affect the ecosystem at large is vital.
"To find out where a fish is underwater, you can't use GPS," joked Gray. Traditionally, companies have used small light sensors in tags to pick up light signals. The light signals then relay the length of day and noon time which is used to determine the latitude and longitude of a fish. Desert Star tags use magnetometers, which work similar to a metal detector in that it detects the magnetic field in the area, and that allows the tag to estimate a latitude location; an onboard solar cell acts as the light sensor and is used to estimate longitude. "The reason we use magnetometers," explained Gray, "is that if you have a fish in really deep water, using a tag that relies on light generally can't produce a position whereas a tag that uses magnets and light levels independently can."
Desert Star uses a proprietary power system to charge their SeaTags. The power system works by storing solar power in tags that are wrapped in a thin film of solar cells or harder wrappings. The solar cell is then connected to a capacitor and as the tag sees sunlight it charges. After nearly fifteen minutes of sunlight the tag retains its charge for up to two weeks in total darkness.
"Prototyping with 3D printing has absolutely helped us discover unknown problems and subsequently fix them," stated Gray. "We recommend to all our engineering collaborators that they use 3D printing to first test their new designs. It is significantly less expensive to have 3D printed parts initially and then machined later once any bugs/re-designing is worked out. It ultimately saves time, money, and re-work."
Desert Star printed 14 PolyJet Otter prototypes and received them within two days -- impossible with other manufacturing processes. Should they need to re-print a part, they could receive it in 1-2 days with 3D Printing. Speed is the real benefit of 3D printing; of course, zero minimum order requirement is a plus. The technology is simply zeroing in on specific products that could require a single part one day, and fifty the next.
The tags have already taken to the sea in research and conservation projects, helping students and professionals alike learn from and protect sharks, marlins, and other sea creatures.
"With the ability to physically hold a prototype in your hand you get a real world feel that no CAD software can do," stated Gray. "This capability benefits any engineering team working on a COTS or even a one-off product. We love 3D printing and look forward to what the future may hold."