The Sensor Systems Lab is working with the UW Applied Physics Lab on underwater wireless power transfer and communication. We are collaborating with David Dyer and Bob Michimoto to transmit power wirelessly via WREL at 1000m depths beneath sea-level to charge power base stations. Tests have shown that the power transmission gain decreases in seawater compared to air and even to fresh water. However, by modifying coil size and various parameters, this loss can be minimized. We have conducted tests to examine the effects that salt water and fresh water have on the wireless power transfer efficiency at both small signal levels, and at high power levels suitable for power transfer. The image on the left shows a test tank for evaluating power transfer efficiency through seawater.