An undersea sensor powered by sound waves could be deployed for an extended period of time to study conditions deep beneath the water’s surface.
One of the difficulties with deploying deep water sensors is their limited battery life, which can be hard to change in devices far beneath the surface. To overcome that obstacle, the team from MIT created an underwater communication system made up of two components: a seabed sensor and a transmitter/receiver located on the surface or shore. An acoustic wave sent through the water by the transmitter will cause the piezoelectric material in the sensor to vibrate and generate an electrical current. That energy is then used by the sensor to either reflect a wave back to the receiver, or not reflect one at all—resulting in a data stream that can be read as either a 1 or a 0.
According to study co-author and assistant professor Fadel Adib, “Once you have a way to transmit 1s and 0s, you can send any information. Basically, we can communicate with underwater sensors based solely on the incoming sound signals whose energy we are harvesting.”