Continuous high-throughput microplastic removal using a fully automated self-cleaning benchtop system based on inertial microfluidics: a pilot study

The rapid increase in global plastic consumption has intensified microplastic contamination, raising concerns regarding ecological and human health impacts. Conventional purification methods, such as membrane filtration and coagulation–flocculation, face limitations including fouling, clogging, and bulky instrumentation, restricting their suitability for compact or point-of-use (POU) systems. Here, we present a fully automated benchtop microplastic removal system integrating a compact spiral microchannel module with an air-driven self-cleaning mechanism, designed to produce microplastic-free water without manual intervention. The platform employs a diaphragm pump, a non-contact water level sensor, and an Arduino-based controller to autonomously alternate between purification and air-flushing modes, maintaining stable focusing and preventing particle accumulation. Using 20–30 μm polystyrene microbeads, the device achieved continuous membrane-free purification with a purified-water collection rate of ∼100 mL/min and an average removal efficiency of 97.6%. High-speed imaging confirmed reliable clog-free operation, and a techno-economic analysis showed clear cost and sustainability advantages over conventional POU membrane units. These results highlight the potential of the proposed benchtop platform as a compact, energy-efficient, and maintenance-free microplastic purification solution for practical POU water purification.