Smog-Mini: A Distributed Micro-Tower Network for Dual PM₂.₅ Filtration and CO₂ Bio-Fixation in Urban Canyons

Mega-scale "smog towers" deliver modest, highly localised air-quality improvements while incurring high capital cost and energy overhead. We introduce Smog-Mini, an open-hardware micro-tower (Ø0.4 m x 2.2m, 18W peak) that fuses electrodynamic PM filtration with a 25 L micro-algae photobioreactor. Deployed as a mesh of rooftop / balcony units, the network performs real-time filtration, carbon bio-fixation and crowd-sensing of PM and CO₂. A 10-unit pilot in Haifa's Hadar district reduced rooftop PM₂.₅ by 35±8% and net-captured 4.1 kg CO₂-eq month⁻¹ with zero grid energy (PV-balanced). All CAD, BOM and firmware are released under CERN-OHL-S v2 / GPL v3.