Power delivery to the human heart from a 200MHz low-frequency transmitter (left) and a 1.7GHz high-frequency transmitter (right) (Image: John Ho, Stanford Engineering)
Implantable medical devices are becoming more common everyday. The problem is that no matter how sophisticated the devices are, most still depend on batteries for power. One solution to this is for the power source to remain outside the body and to beam the power to the device. However, that has its own difficulties because wireless power can’t penetrate very far through human tissue ... until now.