Passive RFID sensors - battery-free, wireless pressure measurements

Wireless sensor systems are key technologies for the Internet of Things (IoT). They are used to measure physical parameters like temperature, pressure or humidity in many industrial environments. One possible solution for these measurements is the application of RFID sensor transponders. RFID sensor transponders combine extremely energy efficient sensors with standard RFID protocols. Passive transponders harvest the complete energy for measurement and communication from the electromagnetic field of the RFID reader. Due to the lack of cable connections or an integrated battery, these sensor transponders can be mounted in difficult to reach positions (e.g. inside machines, encapsulated into compound materials, within or on rotating elements, etc.). Therefore, such sensor systems can be operated for many years without expensive maintenance procedures. The talk will introduce the general concept, show advantages, limitations and the use case of battery-free, wireless pressure sensors, based on the Back-End-of-Line (BEoL) integration of a sensor element on top of the CMOS circuit.