MIT Creates A Battery-Free Underwater Sensor

Scientists are working to explore the oceans around the globe and to enable that MIT has invented a new type of sensor. These sensors will allow scientists to deploy the sensor arrays around the world without worrying about the sensors going offline because of a depleted battery. The sensors are described as using near-zero power to transmit sensor data.MIT researchers think their new sensor could be used to study climate change or track marine life over long periods. The sensors also have the potential to be used in water found on distant planets in the future. The way the battery-free sensor works uses a transmitter to send acoustic waves through the water toward a piezoelectric sensor that has data stored on it.

When the acoustic wave hits the sensor, the material vibrates and stores the resulting electrical charge. The stored energy is then used to reflect a wave back to the receiver, or it doesn't reflect a wave. Being able to alternate when it sends the reflection represents the one and zero of binary code.

The team says that once you have a way to send ones and zeros, you have a way to send any data you want. A test sensor located in an MIT pool collected water temperature and pressure, it was able to transmit data at 3 kilobytes per second, accurately, from two sensors at the same time at a distance of ten meters between the sensor and receiver.

The researchers see the new sensors as a potential benefit to NASA when it sends probes to Saturn's moon Titan in 2026. The battery-free design of the sensors opens the possibility of sensing in extreme environments. Any type of sensor can be integrated into the node by programming the microcontroller inside.