FM TABS: Frequency Modifying RFID Tag Antenna Based Sensing

Problem: Almost a third of perishables become damaged or destroyed during cold supply chain operations. This can be reduced by using better temperature sensors to monitor ambient temperature conditions. Technology: This invention describes a sensor design that uses a shape memory polymer and a metal plate to convert temperature violations into a change of tag antenna properties. This single-use device is secure for audit trails as it cannot be reset once the temperature threshold is violated. The invention also describes a design and design methodology for an UHF RFID tag antenna that shifts its optimum operating frequency between 902 and 928 MHz band when a temperature threshold is exceeded. Christopher Noble crn@mit.edu