The internet of things (IoT) is being merged with the development of technology to simultaneously transmit light and energy to underwater energy devices. Researchers from King Abdullah University of Science and Technology (KAUST), Saudi Arabia, are advancing the use of concurrent lightwave information and power transfer configurations for transmitting energy and data to underwater electronic devices.
The performance of marine sensor and communications systems can be enhanced by a self-powered internet of underwater things (IoUT) that harvests energy and decodes information transferred by light beams. Underwater optical communication offers advantages relative to the underwater acoustic and radio wave communications now in use, including greater distance and capacity of underwater transmission.
Experiments demonstrated stand-alone devices to harvest energy, decode information and perform temperature sensing and video streaming. One test successfully used a blue laser to charge and transmit instructions across a 1.5 m long water tank to a solar panel on a submerged temperature sensor. The sensor recorded temperature data and saved it on a memory card, later transmitting it to a receiver when information in the light beam instructed it to do so.
The battery of a camera submerged at the bottom of a tank filled with ocean water was charged by its solar panel within 90 minutes using a partially submerged, externally powered laser source. The fully charged camera then streamed brief videos back to the laser transmitter.
The research described in IEEE Communications could lead to the design of self-powered underwater sensors for tracking climate change effects on coral reefs, detecting seismic activity and monitoring oil pipelines. The researchers will next develop smart underwater optical positioning algorithms that could help locate relay devices intended to extend the communication ranges of IoUT devices.
