Exactly, moreover they speak about WIFI band, but in the experiment they didn't use an Access Point but a signal generator with the test device at * 2.5cm (0.9 inch) * from the antenna, if I've understood: "For the energy harvesting, we used the 2.45 GHz resonant patch antenna with a return loss of more than −35 dB at 2.45 GHz and a gain of 7 dBi. The antenna is fed by the signal generator at 0 dBm. The antenna is placed at ~2.5 cm away from the MTJ array". Let's try to measure at 2.5 meters. That is a laboratory experiment not intended to prove that you can give power to something moving around. They speak about neuromorphic computing: I know there are devices implanted int the brain of blind people receiving power from a radio device installed very not inside the cranium but at the outside, on the skin. That kind of application is more credible.