## 4 Conclusions  
In this study, an energy harvesting system using piezoelectric materials was designed to serve as an energy source for bicycle paths; the operation of this system was divided based on day and night periods. EPDM was selected as the material for the rubber flooring, and springs were installed under the piezoelectric devices to boost the harvested energy. Furthermore, the appropriate selection and installation of the springs enabled the piezoelectric plates to vibrate actively and continuously, while also protecting the device from damage due to excessive bending.  
When measuring the electrical quantities of the piezoelectric materials assembled on the energy-generating floor, the average voltage was determined to be 15.8 V. When a bicycle moved across the designed system, it applied a load on four piezoelectric plates, thus affording a power of 0.8928 W. In the daytime, energy was generated and stored in the battery. Over a distance of 1 m, 32 piezoelectric plates were installed, which generated a total power of 7.1424 W/m\({}^{2}\). A 12 V NiMH size was selected because it featured a voltage range suitable for a variety of applications.  
To summarize, the energy harvested from this energy source depends on many factors, such as the continuation of the received mechanical force as well as the efficiency of the energy harvesting circuit and piezoelectric materials. Essentially, this study proposed recycling the waste energy from daily life activities and transforming it into electrical energy, to the greatest extent possible. In the future, this approach could be used for an alternative energy source.  
Conceptualization, P.S. and C.J.; methodology, P.S.; software, C.J.; validation, C.J.; formal analysis, P.S.; investigation, P.S.; resources, A.N.; data curation, A.N.; writing--original draft preparation, P.S.; writing--review and editing, C.J. and A.N.; visualization, A.N.; supervision, A.N.; project administration, A.N.; funding acquisition, A.N. All authors have read and agreed to the published version of the manuscript.  
This research was funded by King Mongkut's Institute of Technology Ladkrabang Research Fund, Thailand, grant number KREF046106.  
Not applicable.  
Data Availability Statement: Data are contained within the article.  
The authors wish to gratefully acknowledge the financial support for this research (No. KREF046106) from King Mongkut's Institute of Technology Ladkrabang Research fund, Thailand.  
The authors declare no conflict of interest.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Speed (km/h)** & **Voltage (V)** & **Current (A)** & **Power (W)** \\ \hline
5 & 3.20 & 0.352 & 1.1264 \\ \hline
10 & 3.12 & 0.309 & 1.0976 \\ \hline
20 & 3.20 & 0.343 & 0.9641 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Electrical quantities of the power-generating floor under different driving speeds.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Weight (kg)** & **Voltage (V)** & **Current (A)** & **Power (W)** \\ \hline
55 & 2.87 & 0.328 & 0.9414 \\ \hline
75 & 3.17 & 0.363 & 1.1507 \\ \hline
90 & 3.33 & 0.403 & 1.3420 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Electrical quantities of the power-generating floor under different rider weights.