Measurement of a UHF RFID-Based Battery-Less Vibration Frequency Sensitive Sensor Tag Using Tilt/Vibration Switches

This paper presents a UHF RFID-based vibration frequency sensitive tag using tilt/vibration switches and a proposed new measurement metric, the number of reads per second. The tilt/vibration sensors comprise an internal metal ball and two electrodes; the metal ball changes the short circuited and open circuited status of the two electrodes. The effectiveness of the proposed measurement metric was confirmed by experimental results that showed the metric is sensitive to vibration frequency. Furthermore, the operational mechanism of the proposed vibration frequency sensitive RFID tag was demonstrated using a transparent plastic cylinder and colored plastic balls. This demonstration simulates metal ball movement in the tilt/vibration sensors and confirms the relationship between the vibration parameters (frequencies and amplitudes) and the proposed metric.