Textile electrodes for bioimpedance measuring

Abstract

This article deals with the development and comparison of eight different electrodes made out of a cotton fabric substrate, a silver coated yarn and partly conductive finishes, i.e. a PEDOT:PSS Orgacon ICP 1050 dip-coating and a Powersil coating. The purpose is the application especially in the medical field of angiopathy like for bioimpedance measurements during compression therapies. To be able to compare the suitability of the electrodes, various tests have been performed of the coating abrasion resistance, the stability of electrical resistance values, as well as resistance and bioimpedance measurements. Significant differences between the electrodes regarding their resilience and resistance that are visualized in a value-added analysis were found, with one hand-embroidered, one machine-sewn and one commercial electrode showing optimum properties.

Washing and Abrasion Resistance of Textile Electrodes for ECG Measurements

“…The stitches used were backstitch + zigzag stitch with a step width of 2.5 mm, identical to those in a previous study on Shieldex-embroidered bioimpedance electrodes [23]. The previous experiments found that this kind of stitch combination ideally suited for textile electrodes [23], which is why it was also used here. Powersil coating was applied by a doctor's blade, followed by polymerization for 2 h at 200 • C. PEDOT:PSS coating was performed by dipcoating, followed by drying for 4 h at 60 • C. The following three types of electrodes were produced:…”

“…-Conductive sewing followed by PEDOT:PSS coating (Figure 1b): starting with the aforedescribed electrode with conductive sewing → dipcoating with as-purchased PEDOT:PSS → 4 h at 60 Embroidering of the conductive yarns on the jeans fabric was performed using the sewing machines W6 N1800 (W6 WERTARBEIT Projektierungs-und Handelsgesellschaft mbH, Wennigsen, Germany) and Juki HZL-DX3 (Juki, Röhrsdorf, Germany). The stitches used were backstitch + zigzag stitch with a step width of 2.5 mm, identical to those in a previous study on Shieldex-embroidered bioimpedance electrodes [23]. The previous experiments found that this kind of stitch combination ideally suited for textile electrodes [23], which is why it was also used here.…”

“…In addition to metallization and coating with conductive polymers, textile fabrics can also be made conductive by carbon-based coatings, e.g., with carbon black or graphite. One of the commercial carbon black coatings, Powersil, is often used as a textile coating, but the effects of washing have only scarcely been investigated [23][24][25], and it has not yet been tested with respect to using ECG electrodes after washing or abrasion.…”

Applications of Smart Clothing – a Brief Overview

“…Meding et al reported on the development and comparison of electrodes which were made of cotton fabric as well as a silver-coated yarn and partially conductive poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) Orgacon ICP 1050 with dip coating and a Powersil coating. This electrode is of interest for the medical field of angiopathy as well as for bioimpedance measurements in compression therapies [45]. Jing et al developed a flexible carbon-based thin-film actuator with a 1D-to-2D transition structure, which can be used in smart clothing, soft robots and wearable devices [46].…”

Measuring Biosignals with Single Circuit Boards

“…As glued electrodes for ECG measurements and rigid systems for other measurements are uncomfortable in long-term usage, many approaches to integrate electrodes into clothes or to prepare textile-based electrodes have been reported during the last decades [ 11 , 12 , 13 , 14 , 15 , 16 ]. While these attempts result in increasingly reliable soft textile electrodes and sensors for the detection of ECG and many other biosignals, data evaluation still necessitates either rigid electronics or highly specialized flexible electronics, which are not available for all research groups in the textile or medical area [ 17 , 18 , 19 ].…”