Tiny temperature sensor powered by radio waves (opens in new tab)

Isn't this how RFID, NFC, and Sensormatic have worked for decades?

Seems like the only difference here is a temperature dependent effect, something that every basic diode and transistor has anyway.

According to the article the researchers think they'll be able to achieve a 5m range. Seems like the possibilities for many other kinds of microsensors like these are endless.