## 7 The Case Study
### Kinetic Energy Harvesting Materials Assessment
#### 7.4.2 Piezoelectric Materials  
Many studies provide significant insights that can inform the design of energy-harvesting mats for the Al-Haram Mosque. For example, chalcogenide perovskites exhibit high piezoelectric sensitivity and structural stability [49], making them highly suitable for converting the mechanical energy from pilgrims' foot traffic into electrical energy. Their resistance to environmental stress aligns well with the conditions at the mosque, characterized by high temperatures and humidity. Additionally, the scalability and sustainability of these materials support their application in large-scale installations. Smart mats incorporating chalcogenide perovskites could efficiently power low-energy applications such as LED lighting, sensors, or portable charging stations, aligning with the mosque's innovation and sustainability goals. Lead zirconate titanate (PZT) is another attractive material for harvesting energy from foot traffic, especially in busy pedestrian areas. Its combination of durability, efficient energy conversion, and affordability positions it as an ideal solution for converting footstep pressure into electrical energy, presenting sustainable and innovative opportunities for urban infrastructure. Research [5] has demonstrated the effectiveness of PZT transducers in capturing energy from human footsteps, establishing a strong foundation for their implementation in public infrastructure. PZT stands out particularly because of its stable power output under repetitive mechanical loading. These characteristics benefit high-foot-traffic areas, as continuous pedestrian movement can serve as a reliable source of electricity. For instance, a previous study [3] embedded piezoelectric ceramic diaphragms inside floor tiles, successfully maintaining the durability of PZT under continuous use, thereby ensuring that energy harvesting systems operate effectively over extended periods. Figure 15: The application of T-TENG smart mats within mosque walkways, capturing energy from foot traffic. Beyond standalone PZT systems, researchers have explored hybrid approaches, integrating additional materials or techniques to enhance total energy collection. [PERSON] et al. [16] combined piezoelectric transducers with photovoltaic (PV) cells to simultaneously harness kinetic and solar energy, thus overcoming the limitations of low energy generation per footstep. The inherent flexibility of PZT technology makes it particularly suitable for multi-modal energy harvesting systems designed for urban settings with variable environmental conditions. However, implementing PZT-based energy harvesting walkways introduces several challenges. Individual piezoelectric elements typically generate limited energy, making it necessary to arrange them into arrays or configurations to achieve practical power outputs. Additionally, designs must account for variations in foot pressure and environmental factors, such as moisture and temperature, which significantly influence piezoelectric performance. Ensuring efficient and reliable system operation requires careful engineering, including integration with low-forward-voltage Schottky diodes and the use of series-parallel configurations. PZT-based systems also provide broader advantages for urban infrastructure, contributing to environmental sustainability and energy self-sufficiency. When installed in pedestrian walkways, these systems capture otherwise unused kinetic energy, supplying power to smart-city applications such as sensors and lighting. Recent research [95] indicates that multimodal designs using coupled bending and torsional modes can further enhance energy-harvesting capabilities, expanding the practical applications of PZT systems. Due to its efficient energy conversion and consistent performance under repetitive loads, PZT is particularly suited to walkways and high-foot-traffic areas, and it offers opportunities for hybridization with other renewable energy technologies.