MIT researchers developing sound-powered underwater GPS

Batteryless sensor encapsulated in a polymer before it is submerged in the Charles River (Image: Reza Ghaffarivardavagh)

A battery-free underwater GPS may seem impossible, but three researchers from the Massachusetts Institute of Technology (MIT) are working to make it happen.

At this time, underwater navigation is dominated by acoustic signaling. Battery-powered devices that produce sound are generally limited by the batteries themselves, which are short-lived and require constant charging. When you are working on a project, such as following the movements of a migrating whale, it can be difficult to recharge the batteries that power the device on the whale.

The MIT researchers want to eliminate the battery altogether through a system based on sound reflection instead of generating it.

The key to their findings is underwater backscatter tracking (UBL), a low-power system that works by reflecting acoustic signals from the environment, without the need for batteries.

Researchers are still refining the system through tests in Boston’s Charles River. The ultimate goal is to increase the range of UBLs and test them in the field, in collaboration with collaborators from the Wood Hole Oceanographic Institution on Cape Cod.

“There are so many applications,” researcher Fadel Adib told MIT News. “We hope to understand the ocean on a large scale. It’s a long-term vision, but that’s what we’re working on and what we’re excited about. ”