# Characterization and Theoretical Analysis of the Venus Flytrap Trigger Hair
## 3 Results and Discussion
### Simulation Analysis of the STHCBM with Abaqus
As shown in Figure 9a,b, similar to a STHCBM without notch structure, there is almost no deformation, which is caused by the strain, occurring on the hair lever. The strain of a STHCBM mainly concentrates on the podium. However, the difference is that the strain of the STHCBM with notch structure is more concentrated and four times higher than that of the STHCBM without notch structure. The influence of the geometric parameters of the notch structure in the podium on the strain of the STHCBM is further analyzed. Firstly, keep the minimum diameter of the notch structure \(d\) = 0.6 mm unchanged and changed its distribution position on the podium. The results are shown in Figure 9c, the closer the notch structure to the fixed end of the podium, the greater the strain extreme value will be. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Samples** & \(L_{a}\) **(mm)** & \(L_{b}\) **(mm)** \\ \hline
1 & 10 & 0 \\
2 & 10 & 5 \\
3 & 10 & 10 \\
4 & 10 & 15 \\
5 & 10 & 20 \\
6 & 0 & 10 \\
7 & 5 & 10 \\
8 & 15 & 10 \\
9 & 20 & 10 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Different geometric parameter settings of STHCBM. Figure 7: The maximum strain of the cantilever beam under different elastic moduli: (**a**) cloud map of simulated strain results of homogeneous STHCBM; (**b**) cloud map of simulated strain results of STHCBM with variable stiffness; (**c**) when \(E_{2}\) remains 500 MPa, the maximum strain value of the STHCBM under different \(E_{1}\) values. The orange circles is the results of simulation. In addition, when the distribution position \(X_{d}=2\) mm of the notch structure was constant, and its minimum diameter \(d\) changed. As shown in Figure 9d, the smaller the minimum diameter of the notch structure, the larger the strain concentration effect on it and the strain extreme value will be. Figure 8: The influence of geometric parameters on the mechanical properties of STHCBM: (**a**) the relationship between the deflection of STHCBM and \(L_{d}\), when \(L_{b}\) is 10 mm; (**b**) the relationship between the deflection of STHCBM and \(L_{b}\), when \(L_{d}\) is 10 mm; (**c**,**d**) the relationship between strain, stress, and the total length of STHCBM varies with different external forces. Figure 9: The influence of the notch structure on the maximum strain: (**a**) strain cloud map of STHCBM without notch structure; (**b**) strain cloud map of STHCBM with notch structure; (**c**) the relationship between the distribution position of the notch structure and strain; (**d**) the relationship between the minimum diameter of the notch structure and strain. The above research on the maximum strain of the cantilever beam effectively demonstrates that the diverse characteristics of the trigger hair are beneficial for improving the sensitivity of trigger hair. Therefore, the combination of the characteristics, including a more flexible podium, longer hair, a lighter lever, and a larger constriction structure close to the bottom, is a unique strategy for designing a cantilever sensor that performs well with a good balance between high sensitivity and persistent stability. As a result, based on previous research on the stability of STHCBM, incorporating a notch structure can effectively enhance its sensitivity. However, it is important to note that the introduction of a notch structure may also compromise the overall stability of the STHCBM. Therefore, the optimization of balancing both sensitivity and stability is shown in Figure 10. First of all, for the traditional homogeneous cantilever beam structure, under the action of external forces, there will be strains distributed on the lever, but the strain regions were scattered, and the strain extremes were low (Figure 101). In order to narrow the strain concentration area and reduce the dispersion of strain energy, a measurement of increasing the elastic modulus of the hair lever to enhance its stiffness was taken. In this case, the strain was concentrated at the podium of the cantilever beam (Figure 101).