# Flexible Coated Conductive Textiles as Ohmic Heaters in Car Seats
## 4 Metal-Coating Techniques
### Electroplating  
Electroplating is the process of coating a thin metal layer of reduced metal with the help of an electric current on a conductive substrate. Prior to plating, the substrate should be cleaned to eliminate contamination, bringing about effective attachment of the metal particles to the surface. In general, there are three main phases during cathodic metal deposition: (i) ion migration, (ii) intercalation of adsorbed metal ions, and (iii) electron transfer [38]. The electrochemical deposition has several advantages such as controlling the thickness and morphologies of the deposited metal, and controlling the parameters of plating (time, temperature, and concentration). Additionally, the process only requires low-cost equipment, which makes the process economical and easy [39]. The main drawback during electroplating is that the targeted substrate being plated must already be electrically conductive enough for current to flow through it. Hence, there is a need to activate the textile or polymers prior to electroplating, as they typically function as natural insulators. The non-conductive substrate is normally activated by the making of conductive layers (in a pre-treatment step) on a material surface, utilizing various metals, for example, Ag [40; 41], Cu [33; 42], Ni [43], Mxenes [44], Ni-Co selenide nanowires [45], NiMoO\({}_{4}\)/CoMoO\({}_{4}\) nanorods [46], LaMnO\({}_{3}\)/MnO nanoarrays, ZnO nanostructures stored on a Ni-CuNi conductive layer [47], and LiMn\({}_{2}\)O\({}_{4}\)[48], conductive polymers [49], or carbon-based materials [50]. Figure 4 shows the flow of the electroplating deposition process. The substrate is activated by a metallic nanolayer of Ni\({}_{3}\)Se\({}_{2}\) onto the PES texture, utilizing a three-cathode framework [51]. Cu is one of the most mind-blowing metals for the pre-treatment of material substrates, since it usually covers minor imperfections. As a result of electrodeposition, it is fairly lethargic, has a negligible cost and a high declaration viability, and is significantly conductive [52]. Utilizing a Cu-polythiophene composite film as a seed layer for direct electrodeposition, bringing about a stretchy texture with a high electrical dependability for observation, [PERSON] et al. investigated the in situ deposition of Cu particles on cotton fabric [53]  
Figure 4: (**a**) Schematic electrodeposition process with a three-electrode system; (**b**) average resistance values of differently electroplated conductive threads; (**c**) working principle of the thread sensor that detects chloride ions, pH, and sweat simultaneously; (**d**) SEM image of PET coated uniformly with amorphous NiWO\({}_{4}\); (**e**) SEM of Cu NP-coated PET knitted fabric and corresponding conductivity test. Reproduced with permission from [[PERSON]], [Metallic Layered Polyester Fabric Enabled Nickel Selenide Nanostructures as Highly Conductive and Binderless Electrode with Superior Energy Storage Performance], published by [MDPI], [2017][51]. due to its potential to shield electromagnetic interference. They discovered that 100- and 150-plunge textures with a thick, uniform, and permeated organization of conductive Cu particles on a superficial level displayed the highest level of protection, 10 dB. [PERSON] et al. utilized flexible polyaniline/polyethylene terephthalate (PANI/PET) conductive textiles made by chemically polymerizing PANI on PET textiles and electrochemically depositing Cu crystals for potential e-textile applications [54]. Cu was recently deposited using a new technology called hydrogen evolution-assisted electroplating, which improved deposition rates compared to the conventional electroplating method [55]. [PERSON] et al. reported the use of in situ hydrothermal growth of Cu NPs, with a polydopamine-pre-treated PET knitted fabric as a template. During the long-term cycle test, the resistance-strain behaviour was extremely stable.