## 4 Results and Discussions
### Final Comments  
This research explored and applied the concept of energy harvesting to generate electrical current and power low-power systems. The analytical simulations conducted in Matlab and Simulink, which showed results close to the experiments, validated the relevance of these simulations as valuable tools for study. The developed electronic circuit, consisting of a resistor, full-wave rectifier, and buck-boost converter, was tested and validated in a low-power temperature monitoring system. The promising results indicate that this circuit can be applied in energy harvesting systems, converting mechanical efforts, such as vehicle vibrations, wind, electric motors, machinery, and pedestrian movement, into usable electrical energy to power low-consumption circuits. This technology is especially advantageous in remote or hard-to-reach locations as it extends the time between device recharges and reduces the need for constant maintenance and monitoring.  
The comparison conducted between PZT-5H and P5-13B piezoelectric transducers is essential because their specific properties can lead to significantly different performances in practical applications. This is especially relevant in contexts where optimizing energy efficiency is crucial, such as in low-power autonomous systems. The results obtained in this study can provide valuable insights for engineers seeking to optimize energy harvesting systems, particularly in situations where small efficiency gains can have a significant impact.  
The results presented in this paper reinforce the employment of piezoelectricity in energy harvesting systems to generate energy for low-power loads. Considering the variety of piezoelectric sensors and the variety of mechanisms to convert mechanical energy into electricity by this technology, it is a challenge to find similar systems to compare these results in terms of generated power, for instance. Yet, some cited works can be used as examples and aim to understand the importance of evaluating the efficiency in terms of mechanical energy converted.  
[PERSON] et al. [24] used piezoelectric sensors to generate energy in a biomechanic application, installing these transducers in the fingers of a glove. The hand movement when each finger impacts a keyboard, table, or mouse during standard use can generate a power of 323 mW. Observe that this result represents a great difference in energy harvesting when compared with the application of this work, which employs a vibrational cantilever beam. To understand the origin of this difference, it is important to observe the mechanical energy applied in the movement: while the vibrational system uses free vibration and the inertial mass of vibration, the other system directly converts the applied force from the impact between the fingers of a glove and the solid surface of a keyboard or table.  
The other cantilever beam system tested in Motter [25] also presents low-power-generated energy, similar to this work, which confirms the nature of low-power-generated sources when employing a vibrational system.  
In the opposite direction, following the principles of [PERSON] et al. [24] but extrapolating the example of external force applied in a piezoelectric harvesting system, [PERSON] et al. [26] used PZT-5H (the same transducer used in this work) to create a device embedded in asphalt pavement to generate energy for traffic road facilities. In this case, the external force was derived from vehicles that rolled on the road surface.