Scalable Production of Graphene-Based Wearable E-Textiles

Abstract

Graphene-based wearable e-textiles are considered to be promising due to their advantages over traditional metal-based technology. However, the manufacturing process is complex and currently not suitable for industrial scale application. Here we report a simple, scalable, and cost-effective method of producing graphene-based wearable e-textiles through the chemical reduction of graphene oxide (GO) to make stable reduced graphene oxide (rGO) dispersion which can then be applied to the textile fabric using a simple pad-dry technique. This application method allows the potential manufacture of conductive graphene e-textiles at commercial production rates of ∼150 m/min. The graphene e-textile materials produced are durable and washable with acceptable softness/hand feel. The rGO coating enhanced the tensile strength of cotton fabric and also the flexibility due to the increase in strain% at maximum load. We demonstrate the potential application of these graphene e-textiles for wearable electronics with activity monitoring sensor. This could potentially lead to a multifunctional single graphene e-textile garment that can act both as sensors and flexible heating elements powered by the energy stored in graphene textile supercapacitors.

Keywords: activity monitoring; e-textiles; graphene; textile sensors; wearables.

Figure 1

Schematic diagram of the scalable production of graphene-based wearable e-textiles. Illustration by Daniel Wand and used with permission from the artist.

Figure 2

(a) Flake size distribution of GO and rGO. (b) Flake thickness distribution of GO and rGO. (c) Wide scan XPS spectra of GO and rGO. (d) Raman spectra of GO and rGO.

Figure 3

(a) Untreated cotton fabric was passed through padding bath and rollers. (b) rGO coated cotton fabric immediately after padding. (c) Drying of rGO coated cotton fabric at 100 °C for 5 min. (d) Untreated control cotton fabric. (e) rGO coated cotton fabric after five padding passes and drying. (f) Demonstration of flexibility and drape of rGO coated cotton fabric. (g) SEM image of untreated control cotton fabrics (×1000). (h) SEM image of rGO coated cotton fabric (×1000). (i) SEM image of washed (five times) rGO coated cotton fabric (×1000).

Figure 4

(a) High resolution C (1s) XPS spectrum of control cotton fabric. (b) High resolution C (1s) XPS spectrum of rGO padded cotton fabric. (c) Sheet resistance vs number of padding passes. (d) The change of sheet resistance with number of washing cycles.

Figure 5

Effect of rGO coatings and pigment dyeing on (a) Tensile strength at maximum load and (b) Strain% at maximum load. (c) Shear rigidity, G, and (d) Shear hysteresis at 5°, 2HG5, of cotton fabrics.

Figure 6

(a) The variation in resistance of the bending sensor in forward (bending) and reverse (bending back) direction. (b) The variation in resistance of the compression sensor in forward (compression) and reverse (compression back) direction. (c) The upward and downward movements of rGO coated cotton fabric mounted on a wrist joint. (d) Expanded version of purple box in (c) from 57 s to 77 s.