Investigation of Capacitive-Based Dust Sensor with Nanowires Sensing Layer

Dust particles represent a great challenge in dusty environments due to their accumulation on solar panels which drastically reduces their efficiency. Regular monitoring and cleaning based on dust sensor readings help maintaining the optimal solar panel performance and maximize energy production. However, current dust sensors are based on light scattering, with limitations including bulky size and high power consumption. In this work, Fe₂O₃, ZnO, TiO₂, SnO₂, GaN, InAs, CuO, SiC, V₂O₅, and CdSe nanowires are explored to be used as a capacitive-based sensing layer for dust sensors. Based on extensive simulations using COMSOL and SPICE softwares, ZnO nanowires show a high sensitivity of 7.77% when 25% of the sensor area is covered with dust, and 40.63% when 50% is covered with dust. The sensor capacitance increases from 80 pF to 130 pF as dust particles continue trapping within the spacing between the wires. The change in the capacitance is converted into voltage, where almost 1.2 V is obtained using a readout circuit implemented using a Wheatstone bridge, an instrumentation amplifier, and a full-wave rectifier. Utilizing nanostructures such as nanowires to detect dust levels in outdoor environments has applications in optimizing solar panel performance.