Self-Healing Passive UHF RFID Elastomeric Tags Based on Slot-Type Antennas with Verified Performance Recovery after Mechanical Damage

Abstract

Self-healing materials have emerged as key enablers for flexible and stretchable electronics, particularly in applications requiring resilience under repeated mechanical stress and autonomous recovery. In this work, we present the development and characterization of two fully self-healing passive UHF RFID elastomeric tag antennas, designed with diamond and elliptical slot geometries. Both antennas are fabricated on a soft self-healing elastomer substrate, and an electrically conductive liquid metal-based elastomer is employed as the conductive element. Compared to previous studies, a significant advancement in our work is the increase of the electrical conductivity of the self-healing radiator to ∼20 kS/m, which provides improved antenna impedance characteristics and proper radiation performance. Both antenna prototypes achieve read ranges between 5 to 6.7 m within the 860–960 MHz frequency band, aligning well with simulated results. Measurements after full antenna bisection show sub-minute recovery, with read range restored to 93–100% of the initial level within 60 seconds. The RFID chip is directly mounted onto the conductor without adhesives, preserving both electrical properties and mechanical recovery after physical damage. The attained results demonstrate the feasibility of constructing reliable and recoverable antenna systems entirely from self-healing materials and highlight their potential in the long-term deployment of soft and resilient wireless systems.