Underwater Self‐Powered All‐Optical Wireless Ultrasonic Sensing, Positioning and Communication with Ultrafast Response Time and Ultrahigh Sensitivity

Abstract The utilization of ultrasonic waves in the ocean has become an attractive topic for its applications in underwater sensor networks via a variety of research methods, such as sensing, positioning, and communication. However, it is still challenging to develop a cost‐effective, stable, fast, and accurate wireless underwater ultrasonic device with self‐power‐ability in various circumstances. Herein, a novel underwater self‐powered all‐optical wireless ultrasonic sensor (SAWS) based on triboelectrification‐induced electroluminescence (TIEL) has been proposed, in which efficient and stable TIEL can be generated under the excitation of ultrasonic waves. The SAWS has been demonstrated to accurately determine the location of the ultrasonic source with an error of less than 4.6%, and as a promising candidate for real‐time optical signal communication with an ultrafast response time of below 50 ms and an ultrahigh signal‐to‐noise ratio (SNR) of 26.02 dB. To date, the paradigm‐shift strategy for underwater ultrasonic sensing has been developed for the first time to be fully self‐powered without any wire connections. The SAWS proposed here paves a new path to the realization of a self‐powered underwater all‐optical wireless sensing system that can be effectively applied in underwater environmental monitoring, underwater robots, ocean sensor networks, etc.