Measurement-Based Analysis of Fully Self-Healing Passive UHF RFID Tags
Yaqoob, Isra (2025)
2025
Sähkötekniikan DI-ohjelma - Master's Programme in Electrical Engineering
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
Hyväksymispäivämäärä
2025-12-22
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-2025122212057
https://urn.fi/URN:NBN:fi:tuni-2025122212057
Tiivistelmä
Self-healing passive UHF RFID tags bring sustainability to RFID. In these devices, the structural materials can restore their electrical and mechanical properties after damage. This capability addresses a critical limitation of passive RFID tags, whose antenna performance deteriorates or discontinues irreversibly under mechanical stress. Self-healing polymers and blends are soft, bendable, and self-adhesive materials that offer new solutions for electronics, antenna design, and sensors.
The self-healing material used to fabricate the tags consisted of a nanocomposite substrate and a conductive polymer-based radiator. The substrate was composed of a self-healing elastomer (EC7) matrix reinforced with carboxyl-functionalized multi-walled carbon nanotubes (COOH-MWCNTs), providing mechanical flexibility, durability, and enhanced handling. The loop-matched dipole antenna was formed from a PEDOT-based polymer blend (2PEC7), processed into thick, conductive films to ensure stretchability and conductivity. These films were integrated with the EC7-CNT substrate through the self-healing properties of the materials, enabling robust interfacial bonding. In this work, the designed and prototyped RFID tag antenna was numerically analyzed using a self-healing substrate and conductor with a conductivity of approximately 150 S/m.
This study was conducted to perform measurement-based analysis of fully self-healing passive UHF RFID tags after mechanical damage. This analysis highlights the efficiency and extent of these tags' self-healing, focusing on their backscattered power response, theoretical read range, and transmitted power. The maximum read range of the measured prototyped tag with 2PEC7 at a thickness of 300 µm was approximately 3 m, with an adequate transmitted power of 13.9 dBm and a backscattered power of −41.3 dBm at 915 MHz.
Experimental data demonstrate that the tags recover usable performance after induced defects. After being completely bisected, the tags with a 300 μm conductive thickness regained 82.6% of their read range within 24 hours and remained functional under uniaxial stretching up to 75%, with a read range efficiency of 23.8% after stretching. After 24 hours of multiple cuts, the tag with 200 μm can regain 75.6% of their read range. The results confirm that self-healing materials improve the resilience and reliability of RFID systems, enabling their use in harsh or long-lasting environments where conventional tags fail prematurely.
Further improvements can be achieved by exploring new classes of self-healing polymers and nanocomposites with enhanced electrical conductivity, faster recovery rates, and greater mechanical resilience.
The self-healing material used to fabricate the tags consisted of a nanocomposite substrate and a conductive polymer-based radiator. The substrate was composed of a self-healing elastomer (EC7) matrix reinforced with carboxyl-functionalized multi-walled carbon nanotubes (COOH-MWCNTs), providing mechanical flexibility, durability, and enhanced handling. The loop-matched dipole antenna was formed from a PEDOT-based polymer blend (2PEC7), processed into thick, conductive films to ensure stretchability and conductivity. These films were integrated with the EC7-CNT substrate through the self-healing properties of the materials, enabling robust interfacial bonding. In this work, the designed and prototyped RFID tag antenna was numerically analyzed using a self-healing substrate and conductor with a conductivity of approximately 150 S/m.
This study was conducted to perform measurement-based analysis of fully self-healing passive UHF RFID tags after mechanical damage. This analysis highlights the efficiency and extent of these tags' self-healing, focusing on their backscattered power response, theoretical read range, and transmitted power. The maximum read range of the measured prototyped tag with 2PEC7 at a thickness of 300 µm was approximately 3 m, with an adequate transmitted power of 13.9 dBm and a backscattered power of −41.3 dBm at 915 MHz.
Experimental data demonstrate that the tags recover usable performance after induced defects. After being completely bisected, the tags with a 300 μm conductive thickness regained 82.6% of their read range within 24 hours and remained functional under uniaxial stretching up to 75%, with a read range efficiency of 23.8% after stretching. After 24 hours of multiple cuts, the tag with 200 μm can regain 75.6% of their read range. The results confirm that self-healing materials improve the resilience and reliability of RFID systems, enabling their use in harsh or long-lasting environments where conventional tags fail prematurely.
Further improvements can be achieved by exploring new classes of self-healing polymers and nanocomposites with enhanced electrical conductivity, faster recovery rates, and greater mechanical resilience.