## 4 Experimental Validation
Subsequently, test the output power of piezoelectric components with varying bottom base widths to achieve optimization of the dimension and structural design. In alignment with the analytical methods discussed in Section 3.2, define the size parameter \(k\) as the ratio of the fixed end \(b_{1}\) to the active end \(b_{2}\) for different piezoelectric components. Due to the slender design of the piezoelectric cantilever beam in the theoretical model, further reducing the dimensions at the active end significantly impacts its load-bearing capacity and structural stability, making it susceptible to damage during actual operation. Therefore, the experimental model employs an approach that increases the fixed end \(b_{1}\). Additionally, the effect of symmetrically distributing permanent magnets on the output is also evaluated. Optimization results of piezoelectric components at a relatively stable rotational speed of 250 rpm are illustrated in Figure 14.  
The experimental results indicate that, as the fixed end \(b_{1}\) increased, the magnetically actuated piezoelectric components achieved an increase in output power in the range of \(k\) from 1.2 to 1.6, with relatively maximum power output obtained around 1.4. Based on the analysis in Section 3.2, it can be concluded that increasing the fixed end \(b_{1}\) enhances the structural stiffness, which in turn increases the natural frequency of the piezoelectric cantilever beam. This design effectively increases the change rate of the surface charge on the piezoelectric component, thereby enhancing the output current and improving the output power. And in Section 3.2, optimization of linear elastic piezoelectric cantilever beams has been discussed. When the fixed end of the cantilever beam is increased, the surface charge is approximately constant. Simultaneously, this adjustment increases the equivalent capacitance between the upper and lower surfaces of the piezoelectric layer. This situation results in a decrease in the output voltage of the piezoelectric component. The relationship between these factors necessitates careful consideration, as an increase in equivalent capacitance can lead to a decrease in voltage despite the improvements in current. The results in Figure 14 indicate that when the method, increasing the fixed end  
Figure 14: Optimization tests of output power for piezoelectric components while increasing fixed end \(b_{1}\) at rotational speed of 250 rpm. \(k=b_{1}/b_{2}\). to enhance the natural frequency, becomes less effective after reaching a certain level of increase, the effect on the current weakens. And at this point, there is no longer a significant improvement in the power output. Unlike the simulation analysis that focuses on effect of static force, in the dynamic process of experimental testing, increasing the number of symmetrically placed magnets can significantly reduce the trigger interval of the magnetically actuated piezoelectric cantilever beams' oscillation decay process based on natural frequency, further improving the output power of the piezoelectric component during the rotation process. However, when the number of permanent magnets is excessive, the effect on the output power of the components tends to saturate. It could be suggested that this situation is attributed to the denser magnetic field superposition, which amplifies the magnetic force in areas where it was originally weak, affecting and hindering the vibration of the piezoelectric cantilever beam. It is more suitable to select two to eight permanent magnets and arrange them at equal intervals based on power requirement. Thus, the device is designed by increasing the fixed-end width of the piezoelectric cantilever beam component based on \(k=1.4\), and four permanent magnets are used as the excitation source.