In the current era, energy resources from the environment via piezoelectric materials are not only used for self-powered electronic devices, but also play a significant role in creating a pleasant living environment. Piezoelectric materials have the potential to produce energy from micro to milliwatts of power depending on the ambient conditions. The energy obtained from these materials is used for powering small electronic devices such as sensors, health monitoring devices, and various smart electronic gadgets like watches, personal computers, and cameras. These reviews explain the comprehensive concepts related to piezoelectric (classical and non-classical) materials, energy harvesting from the mechanical vibration of piezoelectric materials, structural modelling, and their optimization. Non-conventional smart materials, such as polyceramics, polymers, or composite piezoelectric materials, stand out due to their slender actuator and sensor profiles, offering superior performance, flexibility, and reliability at competitive costs despite their susceptibility to performance fluctuations caused by temperature variations. Accurate modeling and performance optimization, employing analytical, numerical, and experimental methodologies are imperative. This review also furthers research and development in optimizing piezoelectric energy utilization, suggesting the need for continued experimentation to select optimal materials and structures for various energy applications.

This paper presents the kinetic modeling of biomass gasification in bubbling fluidized bed (BFB) gasifiers and optimization methods to maximize gasification products. The kinetic model was developed based on two-phase fluidization theory. In this work, reaction kinetics, hydrodynamic conditions, convective and diffusion effect, and the thermal cracking of tar kinetics were considered in the model. The model was coded in MATLAB and simulated. The result depicted good agreement with experimental work in literature. The sensitivity analysis was carried out and the effect of temperature ranging from 650 to 850 and steam to biomass ratio (S/B) ranging from 0.1 to 2 was investigated. The result showed that an increase in temperature promoted H2 production from 18.73 % to 36.87 %, reduced that of CO from 39.97 % to 34.2 %, and CH4 from 18.01 % to 11.65 %. Furthermore, surface response was constructed from the regression model and the mutual effect of temperature and S/B on gasification products and heating value was investigated. In addition, the desirability function was employed to optimize gasification product and heating value. The maximum gasification product yield was obtained at 827.9 and 0.1 S/B. The response predicted by desirability function at these optimum operational conditions was 30.1 %, 44.1 %, 13.2 %, 12.9 %, 14.035 MJ/Nm3, and 14.5 MJ/Nm3 for H2, CO, CO2, CH4, LHV, and HHV, respectively. Kinetic modeling of the biomass gasification in BFB process is still under development, which considers the diffusion effect, tar cracking, reaction kinetics, and hydrodynamic behavior. Moreover, the large number of previous studies gave priority to a single parameter investigation. However, this investigation can be extended to various parameters analysis simultaneously, which would give solid information on system performance analysis.

This paper focuses on the mathematical and numerical modeling of a non-classical macro fiber composite (MFC) piezoelectric transducer, MFC-P2, integrated with an aluminum cantilever beam for energy harvesting applications. It seeks to harness the transverse vibration energy in the environment to power small electronic devices, such as wireless sensors, where conventional power sources are inconvenient. The P2-type macro fiber composites (MFC-P2) are specifically designed for transverse energy harvesting applications. They offer high electric source capacitance and improved electric charge generation due to the strain developed perpendicularly to the voltage produced. The system is modeled analytically using Euler–Bernoulli beam theory and piezoelectric constitutive equations, capturing the electromechanical coupling in the d31 mode. Numerical simulations are conducted using COMSOL Multiphysics 6.29 to reduce the complexity of the mathematical model and analyze the effects of material properties, geometric configurations, and excitation conditions. The theoretical model is based on the transverse vibrations of a cantilevered beam using Euler–Bernoulli theory. The natural frequencies and mode shapes for the first four are determined. Depending on these, the resonance frequency, voltage, and power outputs are evaluated across a 12 kΩ resistive load. The results demonstrate that the energy harvester effectively operates near its fundamental resonant frequency of 10.78 Hz, achieving the highest output voltage of approximately 0.1952 V and a maximum power output of 0.0031 mW. The generated power is sufficient to drive ultra-low-power devices, validating the viability of MFC-based cantilever structures for autonomous energy harvesting systems. The application of piezoelectric phenomena and obtaining electrical energy from mechanical vibrations can be powerful solutions in such systems. The application of piezoelectric phenomena to convert mechanical vibrations into electrical energy presents a promising solution for self-powered mechatronic systems, enabling energy autonomy in embedded sensors, as well as being used for structural health monitoring applications.