Synthesis and characterization of zinc oxide reinforced fly ash piezoelectric floor tiles for automated sanitization system application

The fabrication of value-added, technologically savvy, piezoelectric tiles from fly ash-waste produced from coal-burning thermal power stations, and zinc oxide in a suitable ratio (FA-ZnO) through a chemical route is presented. The prepared material is found to have excellent piezoelectric properties with a piezoelectric constant (d₃₃) of 3.3 pC/N, a frequency invariant room temperature dielectric constant as high as 338 and very small tangent loss in the region of 0.02 to 0.007 in the frequency range of 1 kHz to 1 MHz—a boon for its application potentiality. The capacitance and resistance of the tiles are found to increase with the application of pressure/weight. The piezoelectric voltage output exhibits saturation at 200 mV for a cylindrical sample with a cross-sectional radius of 1 cm at the applied weight of 2 kg. As such footfall of a normal human being of 68 kg on a square tile of 10.33 cm side can produce a piezoelectric voltage of 6.8 V. By connecting in series, the layout of the tiles in a busy pathway can harness green energy from the footfall energy. One of the case studies involving the use of the FA-ZnO piezoelectric floor tile as a non-traditional power source for an internet of things (IoT)-based self-automated sanitization system is detailed here with necessary circuitry. The system design comprises a frame mounted on a grid of piezoelectric pavement tiles, which functions as a controlling switch by generating voltage in response to applied pressure on the piezoelectric pavement tiles, and activate the sanitization process-a novel method to maintain hygiene in the workplace.