Embroidered passive UHF RFID tag on flexible 3D printed substrate

3D printing, the latest additive manufacturing technique, has the advantage of
printing complex 3D structures using layer-by-layer deposition of versatile materials. The electrical and mechanical properties of these 3D printed materials can be customized depending on the printing specifications, like infill percentage, in-fill pattern, and thickness. Especially flexible 3D printed material, NinjaFlex, is a highly potential substrate material for wearable passive ultra-high frequency (UHF) radio-frequency identification (RFID) tags. This paper presents the fabrication and wireless evaluation of embroidered passive UHF RFID tags on a 3D printed (NinjaFlex) substrate. The paper outlines the details of the 3D printing of the substrate, the characterization of the substrate material at the UHF band, the embroidery process using conductive yarn, and the wireless measurement results of the fabricated tags. Measurement results show that the manufactured tags achieve peak read ranges of 6 meters. To the best of our knowledge, this is the first demonstration of embroidery on 3D printed flexible substrate. The stability of the results show that this hybrid fabrication methodology offers an easy, quick, and cost-effective approach for manufacturing RFID tags for future wearable identification and sensing applications.