## 2 Materials and Methods
### Process Design  
#### 2.2.1 Fabrication Method  
In fabric weaves, the interchanging double weave is employed for electronic integration in POF fabrics. Both the face and back layers are plain weave. The fabric's looming drafting is shown in Figure 1, where 1 and 2 represent the face warp and weft, and I and II represent the back warp and weft. The configuration of warp and weft yarns can be seen in Table 1. To ensure the luminescent effect and aesthetics of the fabric surface, POFs are used for all face weft yarns. The conductive yarn is only present as weft yarns in the back layer, which better protects the conductive yarn from being damaged by subsequent laser engraving processes. Similarly, to prevent damage to the conductive yarn during the interchanging of face and back layers, the fabric structure near the interchanging area does not contain conductive yarns. The back layer of the fabric has conductive areas, where the POF and conductive yarn are arranged in an alternating pattern in a ratio of 1:1. This arrangement effectively prevents the contact between the conductive yarn in the back layer, which may cause a short circuit. \begin{table}
**Material** & **Placement** & **Content** & **Color** & **Specifications** & **Manufacturer 1** \\ \hline \multirow{3}{*}{Conductive yarn fabric patch 2} & \multirow{3}{*}{Face weft} & Silver-plated nylon fiber & \multirow{3}{*}{Silver grey} & Diameter: 260 D? Resistance: 3.0 \(\pm\) 0.3 \(\Omega\)/cm & Dongguan Shengxin Special Rope Co., Ltd., Dongguan, China Qingdao ThüNGER Textle Co., Ltd., Qingdao, China \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\ \end{tabular} \
\begin{tabular}{c c c} \hline \hline \multirow{3}{*}{
\begin{tabular}{c} Polymeric optical fiber (POF) \\ \end{tabular} } & Face and & Core PMMA, skin fluorine resin & Transparent & Diameter: 0.25 mm Technology Co., Ltd., Yichang, China Qingdao Liuqing Thread Industry Co., Ltd., Qingdao, China \\  & & & & \\ \end{tabular} \({}^{1}\) All manufacturers are from China. All material characteristics are provided by the manufacturer. 2 The conductive fabric is not sticky. It is given stickiness with double-sided tape during fabrication.  
\end{table} 
Table 1: Material specifications. Based on the aforementioned fabric weave design, a sampling process was conducted on the SGA598 Semi-Auto Sampling Loom (Jiangyin Tongyuan Textile Machinery Co., Ltd., Jiangyin, China). During the weaving process, attention was paid to reserving extra length at both ends of the weft yarns (POFs) to facilitate bundling and coupling with light sources (Figure 2c) after the fabric is removed from the loom. Similarly, extra length was also reserved for the conductive yarn at both ends for future connection to the circuit module. After the fabric is removed from the loom, the structure of the fabric's face and back layers is shown in Figure 2a,b. The warp density of both the face and back layers is 96 ends/10 cm, and the weft density is 256 ends/10 cm. The fabric has a width of 24 cm and a length of 20 cm, with an interchange interval of 5 cm. Due to the inherent rigidity and brittleness of POFs, the fabric sample that integrates POFs as weft yarns is stiffer than ordinary fabrics and has limited shear resistance in the weft direction. At the same time, excessive wear of the conductive yarn should be avoided during use in order to ensure the conductivity of the fabric's back layer. Two conductive fabric patches with the dimension of 1.2 cm \(\times\) 3.8 cm are placed between the face and back layers of the fabric, tightly adhered to the back of the \"sensing area\" (Figure 2a) of the face layer. Figure 2d shows the electrical schematic in the fabric sample. The conductive yarn has a resistance of about 3.0 \(\Omega\)/cm, so the conductive yarn interwoven into the fabric's back layer can be equated to four constant-value resistors R in series.