Passive E-Textile UHF RFID-Based Wireless Strain Sensors With Integrated References

Highly stretchable e-textile antennas enable wireless strain sensing based on passive UHF RFID tags. We present two sensors both based on a two-tag system, where one tag antenna is sensitive and one is insensitive toward strain. This way, we achieve novel referenced strain sensors for unambiguous readout. We outline the antenna system development to achieve high EM isolation between the tags and present results from the wireless testing of the sensor.