The effect of bending on laser-cut electro-textile inductors and capacitors attached on denim as wearable structures

Escobedo, P. , de Pablos-Florido, J., Carvajal, M. A., Martínez- Olmos, A., Capitán-Vallvey, L. F. and Palma, A. (2020) The effect of bending on laser-cut electro-textile inductors and capacitors attached on denim as wearable structures. Textile Research Journal, 90(21-22), pp. 2355-2366. (doi: 10.1177/0040517520920570)

Abstract

In this paper we present the design, fabrication and characterization of electro-textile inductor and capacitor patterns on denim fabric as a basis for the development of wearable e-textiles. Planar coil inductors have been harnessed as antenna structures for the development of Near Field Communication (NFC) tags with temperature sensing capability, while interdigitated electrode (IDE) capacitors have been used as humidity sensors for wearable applications. The effect of bending in the electrical performance of such structures was evaluated, showing variations below 5% in both inductance and capacitance values for bending angles in the range of interest, i.e. those fitting to human limbs. In the case of the fabricated NFC tags, a shift in the resonance frequency below 1.7% was found, meaning that the e-textile tag would still be readable by an NFC- enabled smartphone. In respect of the capacitive humidity sensor, we obtained a minimum capacitance variation of 40% for a relative humidity range from 10% to 90%. Measured thermal shift was below 5% in the range from 10 to 40oC. When compared to the 4% variation due to bending, it can be concluded that this capacitive structure can be harnessed as humidity sensor even under bending strain conditions and moderate temperature variations. The development and characterization of such structures on denim fabrics, which is one of the most popular fabrics for everyday clothing, combined with the additional advantage of affordable and easy fabrication methodologies, means a further step towards the next generation of smart e-textile products.

• Item Type: Articles
• Additional Information: This study was supported by projects from the Spanish government (CTQ2016-78754- C2-1-R and EQC2018-004937-P). These projects were partially supported by European Regional Development Funds (ERDF). P. Escobedo wants to thank to the Spanish Ministry of Education, Culture and Sport for a R&D predoctoral grant (FPU13/05032).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Escobedo, Dr Pablo
• Authors: Escobedo, P., de Pablos-Florido, J., Carvajal, M. A., Martínez- Olmos, A., Capitán-Vallvey, L. F., and Palma, A.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Textile Research Journal
• Publisher: SAGE Publications
• ISSN: 0040-5175
• ISSN (Online): 1746-7748
• Published Online: 21 April 2020
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in Textile Research Journal 90(21-22): 2355-2366
• Publisher Policy: Reproduced in accordance with the publisher copyright policy