# Conductive Textiles for Signal Sensing and Technical Applications
## 2 Materials Used to Impart Conductivity on Textiles
### Coating
#### 3.3.1 Dip Coating
A multi-layer dip coating was studied at a thickness of 90-100 nm and electrical resistance of \(<\)400 \(\Omega\) mm\({}^{-1}\) to increase the conductivity of the PEDOT:PSS-coated fibers, and the density and surface tension of the conductive coating solution were varied by altering the mixture ratio, by adding a fluorosulfactant, or by changing the withdrawing speed to achieve a significant, thick PEDOT:PSS layer [238]. [PERSON] et al. organized a two-step dip coating method to establish Ag nanowire networks on the surface of PET materials [239]. The PET substrates were dipped into conductive Ag nanowire solutions and then dried; afterward, the substrate was coordinated vertically to operate the second-step dip coating. The Ag nanowire-coated PET substrates with an order-enhanced analog crisscross structure were prepared. Repeating the multi-layered dip coating method could increase the thickness, improve uniformity, and manufacture the coatings with desired features. Multi-layered dip coating of various coating solutions mainly achieves functional superposition by several deposited films. The fabrication is facile, and it is easy to achieve the multifunctional synergies of each deposited layer. Furthermore, this multi-layer dip coating process benefits broadening the applications of fibrous materials, such as supercapacitors, lithium-ion batteries, and electrode plates. The vacuum-assisted dip coating method has been introduced to maintain the desired coverage of nanoparticles on the substrate surface with minimal defects, including metallic and ceramic fibers. [PERSON] et al. demonstrated a vacuum-assisted LbL assembly technique to construct electrically conductive substances on textiles to develop multifunctional and flexible textiles with superb EMI shielding performances, super-hydrophobicity, and a highly sensitive humidity response [240]. Cotton fabric was coated with a GO nanosheet via the vacuum filtration deposition method [29]. The woven cotton fabric was treated with sodium hydroxide solution. Vacuum filtration deposition was used to disperse the GO nanosheet aqueous solution into the cotton fabric surface to fabricate GO-cotton fabric. Refluxed graphene and polyvinylidene fluoride (PVDF) were mixed and dissolved in absolute ethanol. This mixture was then forcibly deposited into the cotton fabric via a vacuum filtration deposition process, as shown in Figure 4[29; 241]. The spray coating technique uses a spraying device (found on compressed air, such as with an airbrush or spray gun) to deposit conductive materials on the textile surface by the breeze. Any substrate can be coated by this simple, economic, fast, and scalable process, whether it be round or flat, or flexible or rigid [242]. Recently, it has been published that the spray coating approach that applies PEDOT:PSS conductive materials containing 5 wt% dimethyl sulfoxide (DMSO) made highly conductive and multifunctional PET fabrics. PET fabrics were coated with conductive PEDOT:PSS solutions that contain 5 wt% DMSO via spraying conductive material onto the surface of pre-treated PET fabrics [243].