Self-Healing UHF RFID Tag Antennas: The Concept and First Results with a Slot-Type Antenna

Self-healing functional polymers, composites, and blends have the potential to provide cutting-edge solutions for advancing fully soft, elastic electronics, antennas, and sensors. In this letter, we present the first prototype and performance evaluation of a slot type passive UHF RFID tag antenna made of self-healing insulative elastomer substrate and self-healing conductive laser cut PEDOT:PSS-based blend film. The measured maximum read range of the self-healing tag varied from 1.7 to 1.8 meters within the frequency range of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$860-960 \text{MHz}$</tex>, which covers the UHF RFID bands used worldwide. Taking into account the current conductivity of the self-healing polymer <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(150 \mathrm{S} / \mathrm{m})$</tex>, this is a promising result and demonstrates, for the first time, a completely self-healing polymer-based UHF RFID tag antenna. In addition, we have demonstrated direct attachment of the RFID IC strap to the radiator without any additional adhesives. Moreover, the good agreement between the simulated and measured data confirms the applicability of the antenna modelling approach to the fully self-healing elastomer-based antenna. The work presented in this paper provides proof-of-concept in development of self-healing antennas, sensors and electronics. One of the most important aspects for future work is increasing the conductivity of the self-healing polymer.