Fully Printable, Folded, High Frequency Chipless RFID Tag for Surgical Tracking and Detection

We present the first multilayer, foldable chipless RFID tag design that works in the high frequency (HF) range. To reach such low resonant frequencies (in the order of 10 MHz) a parallel plate capacitor is used in series with a planar rectangular coil. To build the capacitor avoiding the use of vias a foldable design is presented. This tag design enables new applications where materials are too lossy at higher frequencies, such as in-body bio-sensing. We explore its application in tracking surgical sponges, characterizing its response when covered in blood, both via simulation and measurements.