Development of a Reusable PM SAW Sensor System with a Microheater and Porous Microstructure Filter Membrane for PM10 and PM2.5 Detection

This study presents a novel surface acoustic wave (SAW)-based particular matter (PM) sensor system integrating a microheater and a filter membrane for simultaneous and individual detection of PM10 and PM2.5, while also ensuring sensor reusability. The sensor utilizes a 2-port SAW resonator platform with a uniquely designed porous membrane (mechanical filter) featuring <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3\ \mu\mathrm{m}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$11\ \mu\mathrm{m}$</tex> holes. Fabricated using advanced photolithography and electro-plating techniques, the membrane ensures selective particle detection. The built-in microheater facilitates PM particle detachment. Additionally, the system includes custom interface electronics for real-time monitoring, advancing particulate matter sensing with improved selectivity, reusability, and stability.