The vast expanse of the ocean floor hides a hidden treasure trove of resources in the form of polymetallic nodules. These small, potato-shaped mineral deposits hold valuable metals such as manganese, nickel, copper, and cobalt. As the demand for these critical metals increases, there is a growing interest in developing sustainable methods to extract them. One of the primary challenges is minimizing the sediment plume generated during collection and the negative environmental impact. At Impossible Metals, we are exploring a novel approach that utilizes an autonomous underwater vehicle (AUV) with unique hovering capabilities and specialized arms to gently collect nodules, aiming to minimize sediment suspension and ultimately create no plume.

A Gentle Touch

Traditional nodule collection methods often involve heavy machinery that disturbs the ocean floor, resulting in a significant sediment plume that can have adverse effects on the marine ecosystem. In contrast, the AUV technology we are developing uses novel technology to overcome this problem. By hovering above the seafloor, the AUV minimizes its contact with the sediment, and we expect this to reduce disturbance and minimize the generation of a sediment plume.

The AUV’s arms, strategically positioned at the bottom of the vehicle, play a crucial role in achieving the gentle collection of polymetallic nodules. These arms are designed to pick up the nodules individually, minimizing impact on surrounding sediment. By carefully collecting each nodule, we anticipate that the AUV will limit sediment resuspension, thus significantly reducing the potential environmental impact.

Testing for Excellence

Impossible Metals uses a specialized test tank to refine the design and optimize the arm and end effectors (hands, etc.) that pick up nodules. Designers and researchers use the tank to evaluate and compare the effectiveness of different end effector designs and measure the amount of sediment suspended during nodule pickup.

While the current testing involves sediments that differ from those found in seabed nodule fields, it provides valuable insights into the sediment suspension behavior of various end-effector designs. Researchers can fine-tune the AUV’s collection system by experimenting with nodules of varying sizes, burial depths, and pick speeds. Our team uses this testing process to continually improve the technology toward our goal of minimizing sediment disruption.

Why This Matters

If you’ve read this far and are thinking, why bother the deep seafloor at all? That’s a good question. Scientists agree that moving away from fossil fuels is essential for a low-carbon future to limit the impacts of climate change. However, renewable energy requires specific metals for things like batteries and electronics. To reach our global climate goals by 2035, 384 new mines would be required to supply the increasing volume of critical metals, all with their own environmental and social impacts, including in some jurisdictions where human rights abuses in mining are commonplace, including child labour. 

At Impossible Metals, our goal is to harvest critical metals from the seafloor with minimal impact on the ecosystem. Our end effector testing and optimization is one of the ways that we are working toward that goal.