# Flexible Coated Conductive Textiles as Ohmic Heaters in Car Seats
## 6 Design of Heating Fabrics Seats and Thermo-Electric Response
The electrical energy performance, highest temperature, and temperature-response rate were computed by a three-part analysis of the temperature versus time curve to explore the resistive heating performance of the laminated composites. Later, the impacts of ohmic heating behaviour on the structural collapse and mechanical properties of the composite materials were examined using dynamic mechanical analysis and X-ray micro computed tomography [88]. A test setup with a power source and an IR camera (865 Testo UK) was used to observe the heating properties of laminated composites (Figure 12). The electrodes were kept 7 cm apart by having the power supply fastened to CF at two of the composite's edges. The IR camera recorded the temperature in the centre of each composite during the heating process while being placed 10 cm above the surface. Prior to further analysis, all samples, identified as CH1, WH1, CH2, WH2, WH3, and CH3, were continuously heated for 10 h at 3 V to study heat ageing. The carbon nanotube (CNT) layer on the nylon yarn makes it an excellent conductor of electricity and heat. The goal of this research was to coat the CNT with Nylon 6/Spandex  
Figure 12: Time-dependent temperature changes of CF composite laminates and ZnO/CF composite laminates with different CF layers at applied voltages: (**A**) 2 V; (**B**) 3 V; and (**C**) 4 V. CF represents carbon fibre. Reproduced with permission from [[PERSON]]. [Utility of whiskerized carbon fabric sur-faces in resistive heating of composites. ]; published by [[PERSON]], [2021][88]. yarn to produce electrical conductivity. SEM analysis was used to investigate the physical properties of CNTs. The electrical properties of yarns coated with CNTs in stretched and relaxed states were explored. The conductive yarns revealed a poor resistance when subjected to a high stretch load. Moreover, the heating efficiency of the yarns coated with CNTs was investigated by applying a variety of voltages to the yarn's surface. The maximum temperature was around 280 \({}^{\circ}\)C when the voltage was 5 V for 60 min [89]. Nylon6/Spandex yarns were treated with a sodium hydroxide solution containing CTAB as the dispersing agent. Then, 1 g/LCTAB and 5 g/L NaOH were combined to produce the solution at room temperature. The prepared solution was then dipped into Nylon6/Spandex yarn, and the M: L (material to liquor) ratio was set at 1:40. For 1 h, the entire assembly was heated to 60 \({}^{\circ}\)C. Following that, the yarn was thoroughly rinsed with distilled water and dried. In the second stage, 1 g of CNT was mixed with 0.5 g/L of deionized water dye solution. The mixture was sonicated in a (BANDLIN, SONOPULS) sonicator for 60 min [90]. Every hour, the solution's conductivity was tested, and its pH was also adjusted (by adding acetic acid dropwise). The pH and electrical conductivity of the solution were measured continuously until constant conductivity values were attained. As a result, the pH was adjusted to 6.5 using acetic acid. The alkali-treated yarn was then immersed and placed in a CNT dispersion for half an hour at room temperature before drying at 50 \({}^{\circ}\)C. Dipping in solution and drying were performed indefinitely for 5, 10, 15, and 20 cycles, respectively, to improve CNT loading. Finally, the yarns were post-cured in an oven at 180 \({}^{\circ}\)C for an hour. Figure 13 depicts the entire process involved in the application of CNTs to the yarns. The production and passage of charge during CNT development stimulates the additional electrons. Electrostatic interaction is the most likely type of interaction between polyamide and CNTs since the majority of polyamides are positively charged [91]. Table 1 provides an overview of the most recent studies.