Textile-Integrated Stretchable Structures for Wearable Wireless Platforms

In this study, antennas for passive UHF RFID tags were created from a carbon-based stretchable conductor on a stretchable elastic band by brush-painting. The antennamicrochip interconnections were fabricated by two different ways: 1) by using already commonly reported gluing with conductive silver epoxy and 2) by sewing the IC with conductive yarn. In addition to wireless evaluation of the fabricated RFID tags before and after stretching, we evaluated the effects of the interconnection type on tag performance and reliability. The achieved read ranges of around 1.5 meters are suitable for versatile textile-integrated RFID applications. Stretching causes permanent decrease to the tag read range but they remain functional even after 100 stretching cycles. In addition, the tags with the embroidered interconnections were found to be more reliable towards harsh stretching, compared to the tags with glued ICs. These initial results are very encouraging, considering the current trend towards more ecofriendly and cost-effective materials in electronics.