## 3 Effect of Tension and Compression
### Results and Discussion  
First of all, we clarified the length of conjugated double bond of MCF in our previous studies [34; 38] as shown in Figure 10 in Appendix A, which is an example of electric current and tension. The length of the conjugated double bond lengthens via electrolytic polymerization and the application of a magnetic field. Therefore, through these factors, the photovoltaics are enhanced. The effects of compression and tension on the built-in electricity and photoelectricity (for voltage and current density, respectively) and the electrical resistance corresponding to the built-in electricity and photoelectricity are shown in Figures 11-12. These effects are presented as changes from the initial state (with neither compression nor tension) due to compression or tension. Here, the MCF rubber contained 3 g of TiO\({}_{2}\), 6 g of Ni, 4.5 g of MF, and 9 g of NR latex. Where the compressive strain changed, the tension or tensile strain remained constant under the compression. Where the tensile strain changed, the pressure remained steady under the tension. If we consider the effect of either compression or tension individually, the case at 0 mm tensile stress or 0 Pa pressure is indicated in the figures. In the cases of voltage and electric current, the compressive strain-pressure relationship and the tensile strain-stress relationship are also shown (Figures 11 and 12). While the former was only a linear relation, the latter had linear elastic and plastic regions. Figure 9: Photograph of the experimental apparatus for measuring the built-in electricity and photoelectricity of MCF rubber DSSCs under tension and compression. Built-in voltage and current under increasing compression and tension tended to first increase and then decrease and remain constant. The enhancement occurred with the smallest compression or tension, and, in the case of tension, it occurred in the inner linear elastic region. On the other hand, while photovoltage and current under increasing tension showed the same tendency, under increasing compression, they showed a different tendency, without the initial increase. In contrast, regardless of condition, electrical resistance tended to show the first pattern, that is, an initial increase, followed by a decrease, after which values held constant. Figure 13 shows a microscopic model that explains these results, with electrons and holes bringing about photoelectricity and ions bringing about built-in electricity (Figure 5). The behaviors of the particles of Fe\({}_{3}\)O\({}_{4}\), Ni, and TiO\({}_{2}\), and the molecules of rubber, water, a mixture of potassium iodide (KI) and iodine (I\({}_{2}\)), and electrons as shown in Figure 5 are presented in Figure 13, and their configurations are different from those of ceramic and metal. Figure 10: Effects of compression and tension on voltage as built-in electricity and photoelectricity: (**a**) as built-in electricity, under compression; (**b**) as photoelectricity, under compression; (**c**) as built-in electricity, under tension; (**d**) as photoelectricity, under tension. Although the rubber prevented the particles and the molecules in Figure 13 from moving, the position of the particles and the molecules could move elastically in accordance with the rubber's deformation via compression or tension. In the case of compression, as shown in Figure 13a, because the distance between the electron and the hole or between ions was narrowed, the voltage and electric current were increased. Under sequentially greater compression, the electron and hole became contiguous such that the voltage and electric current were zero, and, at further compression, the situation of the electron and hole was inverse such that the voltage and electric current attained negative values. On the other hand, in the case of tension (Figure 13b), because the distance between the electron and the hole or between ions was widened, the voltage and electric current decreased.