Decreasing IoT power usage via the carrier wave→

The Economist: (paywall warning)

The system they have designed has a central transmitter (which might be built into a Wi-Fi router) that broadcasts a pure carrier wave. Dr Gollakota’s new chips then impress binary data on this carrier wave by either reflecting it (for a one) or absorbing it (for a zero). Whether a chip reflects or absorbs the signal depends on whether or not its aerial is earthed, which is in turn controlled by a simple switch.
Not having to generate its own carrier wave reduces a chip’s power consumption ten-thousandfold, for throwing the switch requires only a minuscule amount of current. Moreover, though Dr Gollakota’s prototypes do still use batteries, this current could instead be extracted from the part of the carrier wave that is absorbed.

I’m really looking forward to how hilariously expensive WiFi routers are going to be in thirty years when we’ve all got ten thousand internet-connected devices that are all being powered by wireless power transmission.