Tiger shark tagged with SeaTag-MOD (Image courtesy of University of Miami, RSMAS)

The vast oceans of the world cover approximately 72% of our planet's surface and contain 97% of the Earth's water. Given the fact that oceanographers are convinced that only 5% of the oceans have been explored, their 310 million cubic miles of area and average depth of 12,080 feet contains mysteries which may never be fully revealed.

The oceans are home to some 230,000 known species, and it's thought that some two million yet to be discovered marine species roam their depths.

In an effort to take on the monumental task of understanding what goes on beneath the waves, additive manufacturing technology is at the forefront of molding the tracking tags scientists use to understand the creatures who live there.

Desert Star Systems, a Northern California manufacturer of advanced underwater technology, now uses AM to prototype tags for sea animals to track their migrations and movements. The company's latest innovation, SeaTag animal tags, can work at lower depths, survive longer, and withstand extreme environmental abuse.

Using 3D printed prototypes, Desert Star worked to make tags which conform precisely to the bodies of various undersea creatures.

SeaTags, used by researchers to gather details about the way sea life interacts inside various areas of the ocean, are capable of estimating the temperature of the water, depth of the animal, a creature's movement and acceleration measurements and even oxygen levels in the surrounding water.

"Our goal is to develop very specific sizes and shapes of animal tags in very odd – and very unique – shapes that we would otherwise need injection molding to make," said 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."

To create the prototypes of the tags, Desert Star made 3D CAD files as blueprints for prototypes of shark fin tags, marlin tags, dolphin tags, and sea otter tags.

Experimentation with stereolithography, selective laser sintering and fused deposition modeling made it feasible for Desert Star to 3D print very smooth and complex molds for tags. The molds were then filled with polyurethanes and assembled to create finished devices.

Gray says Desert Star tags use magnetometers, which function much like a metal detector in that they detects the magnetic field in a particular area, and that allows data from the tags to estimate a latitude location. On board solar cells act as the light sensor and are used to estimate longitude.

"The reason we use magnetometers 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," Gray said.

The tags are powered via a proprietary system used to charge them by storing solar energy in cells wrapped in a thin film. The solar cell is connected to a capacitor, and as the tag is exposed to sunlight, it charges. After exposure to fifteen minutes of sunlight, each tag retains a charge for up to two weeks in total darkness.

"Prototyping with 3D printing has absolutely helped us discover unknown problems and subsequently fix them," Gray says. "It's significantly less expensive to have 3D printed parts initially. It ultimately saves time, money, and re-work. With the ability to physically hold a prototype in your hand, you get a real world feel that no CAD software provides."