RFID-Enabled Temperature Sensor

I.M. Abdel-Motaleb[1], K. Allen [1]
[1]Department of Electrical Engineering, Northern Illinois University, DeKalb, IL, USA

The design of a RFID-enabled temperature sensor is described in this paper. In this sensor, a change in temperature causes structural beams to bend, which results in a proportional displacement of the plates of the capacitor. Plates\' displacement results, in turn, in changing the value of its capacitance. The capacitor of the sensor is coupled to the LC resonant network of a passive RFID tag. This makes the tag\'s resonance frequency dependent on the value of the sensor\'s capacitance. Hence, by measuring the shift in the resonance frequency, one can measure the change in temperature. COMSOL multiphysics program was used to design the sensor and simulate its performance. Simulation results show that the designed sensor can have a resolution of about 0.0014 °C/Hz. This sensor can be implanted on a tooth or a dental implant to monitor the mouth temperature.