## 7 The Case Study
### Kinetic Energy Harvesting Materials Assessment
#### 7.4.4 MXene-Based Materials  
Recent advancements in MXene-based materials [6; 63] provide an excellent foundation for developing innovative smart mats designed to harvest kinetic energy in high-foot-traffic environments such as the Al-Haram Mosque. MXene-based triboelectric nanogenerators (TENGs) can be integrated into flooring systems or wearable devices to capture energy effectively. For instance, flexible MXene-based nanogenerators embedded within flooring surfaces can convert pressure and vibrations from footsteps into usable electrical energy. This harvested energy can power lighting systems and sensors or be stored for later use [6; 63]. Then, the flexible MXene-based nanogenerators can achieve high energy-conversion efficiency even under low-frequency mechanical stimuli, such as human footsteps. Additionally, the high surface area of MXenes enhances the triboelectric effect by increasing the contact area during mechanical deformation, thus generating more charge. These features make MXene-based TENGs particularly suitable for urban environments, where foot traffic is frequent and covers large areas. MXene materials exhibit strong mechanical properties, allowing them to withstand repetitive and varying pressures from millions of pilgrims walking over the mats. Furthermore, MXenes can be integrated into polymer matrices or layered structures, providing flexibility and resilience [6]. This integration is essential for mats that need to sustain high traffic while maintaining comfort. However, current studies discussing MXene-based materials remain somewhat limited. In terms of their application in kinetic energy harvesting, MXene-based materials offer high electrical conductivity, excellent mechanical flexibility, and hydrophilicity, making them well-suited for layering with other materials. They can be effectively used in pressure sensing, motion tracking, and energy harvesting--particularly within hybrid systems--and as touch-sensitive mats or zones for tracking worship movements. While MXene mats alone may not inherently generate energy in the same way as purely piezoelectric or triboelectric materials, hybrid MXene-TENG and MXene-Piezo systems have demonstrated promising energy generation, reaching between 1 and 10 mW/cm\({}^{2}\) in real-world testing, depending on design specifics. MXene significantly improves charge transfer and energy output efficiency in these hybrid systems. Figure 19 illustrates a worshipper interacting with a smart prayer mat embedded with MXene nanosheet films, demonstrating high sensitivity to pressure and bending. The mat's layered structure consists of a flexible substrate, a conductive interlayer, and an active MXene sensing layer optimized for accurate motion tracking and signal generation. Directional arrows illustrate the real-time signal flow produced in response to movements such as sujood or applied foot pressure. A small digital readout simulates potential integration with IoT systems, highlighting the potential for smart infrastructure within mosques. MXenes enhance sensor responsiveness because of their high conductivity and large surface area, making them particularly effective for human-interactive systems related to prayer movements. Figure 18: Biodegradable Cellulose Composite Mat for Mosque Use. Figure 20 further highlights MXene-enhanced smart mats used within a mosque setting to monitor movements and pressure. The labelled cross-sectional view details the integration of MXene films, conductive electrodes, and supportive flexible substrates. These mats effectively detect motion patterns, such as walking or standing, and convert these movements into real-time sensor data. Digital and graphical indicators illustrate the mat's sensitivity and efficient, low-power signal generation capabilities. Such technology holds promise for applications in smart facility management, prayer analytics, and energy-efficient environmental control systems in large-scale mosques. Figure 19: MXene-Based Smart Prayer Mat for Pressure Sensing and Signal Output.