Sensor could lengthen navigational time of vehicles underwater

Exploring the depths of the sea or ocean worlds may soon become much easier, thanks to an underwater metamaterial sensing system design developed by Broadman et al.

Autonomous vehicles that can map out the ocean can “see” underwater, thanks to a complex array of sensors, their electronics, and post-processing algorithms. While this setup works well, it consumes a large amount of power, drastically limiting navigation time.

To tackle this issue, Broadman et al. designed a leaky wave antenna, an architected elastic antenna that, like a traditional underwater sensor, can steer sound waves underwater. Unlike traditional devices, however, the modeled antenna only requires a single source or sensor and, therefore, requires much less power.

“LWAs show promise especially for autonomous systems exploration, where physically small, low-energy devices are needed for long-term monitoring,” coauthor Craig Broadman said.

Using finite-element analysis, the authors simulated how a leaky wave antenna with a specific geometry and composition would steer sound waves underwater. They iterated on their simulation until they found a device that could direct sound waves by changing the input frequency.

Broadman said the authors would like to actually fabricate and test the sensor they designed, but doing so would require large volumes of water and highly specialized equipment.

“Facilities [for building the underwater leaky wave antenna] do exist but are not readily available or easily accessible at the present time,” Broadman said. “With that being said, the design approach highlighted in this paper is easily scalable to a wide range of frequencies and operational platforms.”

Source: “Design of a one-dimensional underwater acoustic leaky wave antenna using an elastic metamaterial waveguide,” by Craig W. Broadman, Christina J. Naify, Michael J. Lee, and Michael R. Haberman, Journal of Applied Physics (2021). The article can be accessed at https://doi.org/10.1063/5.0044802 .

This paper is part of the Acoustic Metamaterials 2021 Collection, learn more here .