Embroidery Textile Moisture Sensor

Abstract

In this work, two embroidered textile moisture sensors are presented. The sensors are based on a capacitive interdigitated structure embroidered on a cotton substrate with an embroidery conductor yarn composed by 99% pure silver plated nylon yarn 140/17 dtex. In order to evaluate the sensor sensitivity, the impedance of the sensor has been measured by means of a LCR meter from 20 Hz to 20 kHz on a climatic chamber with a sweep of the relative humidity from 25% to 65% at 20 °C. The experimental results show a clear and controllable dependence of the sensor impedance with the relative humidity. Therefore, this dependence points out the usefulness of the proposed sensor to develop wearable applications on health and fitness scope.

Fabrics and Garments as Sensors: A Research Update

“…A nylon core wrapped with three stainless-steel filaments can be sewn with an embroidery machine [35]. Silver-plated nylon yarn (140/17 dtex) was embroidered on cotton fabric (0.43 mm) and demonstrated to perform as a humidity sensor between 25% and 65% at 20 °C based on changes in impedance [56]. Subsequently, the same researchers determined that Shieldtex ® 117/17 dtex 2-ply (polyamide and silver) had lower sensitivity to humidity (30% to 65%) than Bekaert yarns of 80% polyester/20% stainless steel, 80% cotton/20% stainless steel embroidered on 100% cotton (0.43 mm) [54].…”

“…This is important due to the effects of temperature and moisture presence on electrical properties as well as on many fiber types. For example, a change in humidity (25% and 65% at 20 °C) caused a change in the impedance of cotton fabric (0.43 mm) with embroidered silver-plated nylon yarn [56]; and a graphene/methyl-red composite and silver nanoparticles inkjet printed on polyethylene terephthalate showed reduced electrical resistance with increased relative humidity [191]. In terms of changes in temperature, the change in electrical conductivity of a graphene-based sensor in response to carbon dioxide differed when conditions of 40 °C and 60 °C were compared to 22 °C [192], and a graphene nanowall film on polydimethylsiloxane increased in electrical resistance from 706.2 Ω at 25 °C to 98.04 KΩ at 120 °C [193].…”

Impact of Conductive Yarns on Embroidery Textile Moisture Sensor

“…This work is an extended version of the previous paper published by the authors at EUROSENSOR conference 2018 [8]. In [8] an embroidered textile sensor in order to measure the moisture was presented.…”

“…This work is an extended version of the previous paper published by the authors at EUROSENSOR conference 2018 [8]. In [8] an embroidered textile sensor in order to measure the moisture was presented. In this extended version, a comparison of the electrical properties of the electrical sensor with several types of conductive yarns are analysed and assessed.…”

Experimental analysis of fabric substrate on a moisture sensor

“…Nowadays the possibilities that embroidered sensors can provide are unlimited. There are a lot of different substrates where a sensor could be embroidered on to gather data from the environment or the human body [13]. The two most used materials for textiles are cotton and polyethylene terephthalate [14,15,16].…”