Powered by Radio Waves. bgr.com/2015/12/08/iot-devices-sensor.... Remarkable new sensor chip pulls power out of the air so it never needs to be charged. And I used to laugh at people who asked why we don't charge it over Wi-Fi. Powered by Radio Waves bgr com/2015/12/08/iot-devices-sensor Remarkable new sensor chip pulls power out of the air so it never needs to be charged And I used laugh at people who asked why we don't charge over Wi-Fi