Given the deepwater working conditions endured by submarines, one of the last things most people would want to do is drill holes through their hulls. That's exactly what is necessary, however, to allow power and data to flow to and from audio and other sensors mounted on the exterior of the vessels. Not only do these holes present a leakage risk, but they also diminish the hull's structural integrity, and the submarine must be hoisted into drydock in order for any new sensors to be added. Now, a doctoral student at New York's Rensselaer Polytechnic Institute (RPI) has come up with a method of using ultrasound to transmit power and data wirelessly through a sub's thick metal hull – no holes required.
The system, created by RPI Electrical, Computer, and Systems Engineering student Tristan Lawry, utilizes piezoelectric transducers to convert electrical signals into acoustic signals and vice versa. Power and data are relayed via separate non-interfering ultrasonic channels. Conventional electromagnetic wireless technology, by contrast, is thwarted by the shielding effect of metal hulls.
In lab tests, Lawry has simultaneously and continuously transmitted 50 watts of power and 12.4 megabytes per second of data through a 2.5-inch-thick (63.5 mm) solid steel block in real time. These numbers are reportedly far better than those attained in previous attempts at ultrasonic data and power transmission through metal, thanks to the digital technology utilized. The tests are also said to mark the first time that high levels of power and data have been transmitted through metal simultaneously.
Lawry believes that with minor tweaking, his system could handle even higher data rates and power levels. He stated that the thickness of the metal is not a significant challenge, nor are imperfections on its surface such as rust, or imperfectly-mounted transducers.
Besides its use on submarines, Lawry believes his system could also ultimately be utilized in nuclear reactors, chemical processing equipment, oil drilling equipment and pipelines, armored vehicles, or space shuttles and satellites.