Underwater Optical Wireless Data and Power Transfer System for Internet of Underwater Things

The internet of underwater things (IoUT), a network of underwater objects, enables continuous and effortless monitoring of the oceans. The conventional IoUTs are battery-powered, which limits their lifetime and leads to environmental hazards when discarded. To address this, we propose a sustainable IoUT scheme that enables optical wireless charging of underwater nodes, extending the lifetime. The scheme utilizes optical wireless information and power transfer for data collection and charging IoUT nodes. An underwater optical wireless communication (UOWC) experiment is set up to demonstrate the optical wireless charging of an IoUT node and data acquisition from the node. The system’s performance under various underwater conditions is evaluated with blue, blue-green, and red lasers. The energy efficiency of the node is evaluated for different channel conditions by measuring the charging current using a battery charge monitor. The charging current varies with channel conditions, recording minimum values of 838.6mA at a maximum salinity of 35.2ppt, 838.3mA at a maximum Maalox concentration of 100mg/l, 839.5mA at a maximum channel temperature of 35°C, and 838.2mA at a maximum channel length of 2.5m.