Multi-chip RFID Tags integrating Shape-memory Alloys for Temperature Sensing

Abstract

This paper proposes a dual-chip UHF tag embedding Shape Memory Alloys (SMA) able to tranform the variation of the tagged item’s temperature into a permanent change of antenna radiation features. This event-driven antenna is hence able to selectively activate the embedded microchips according to the temperature above or below a given threshold. A general design methodology for the resulting two-ports tag antenna is here introduced and then applied to prototypes able to work at low (around 0◦C) and high (80◦C) temperatures. The devices has clear applications in supply chain management as well as general safety assessment.