New wireless communication technique uses magnetic signals

MIT Technology Review : As people accumulate more wearable electronics, such as smart watches and fitness trackers, good communication among the devices will be needed. Current wireless systems use Bluetooth, which transmits information via radio waves. However, Bluetooth requires a lot of power because the human body tends to absorb the radio signals. Magnetic fields, however, can pass right through biological tissue. Now Patrick Mercier of the University of California, San Diego, and coworkers are developing a prototype device that transmits data through the human body using magnetic fields. Because magnetic fields follow a circular path, the device consists of PVC-insulated copper wires that wrap around a person’s head, arms, and legs. Although the technology is still in development, the researchers say that it could one day be integrated into a device that encircles a body part, such as a watch, headband, or belt.