Electrohydrodynamic enhanced transport and trapping of airborne particles to a microfluidic air-liquid interface

We introduce a novel approach for greatly improved transport and trapping of airborne sample to a microfluidic analysis system by integrating an electrohydrodynamic (EHD) air pump with a microfluidic air-liquid interface. In our system, a negative corona discharge partially ionizes the air around a sharp electrode tip while the electrostatic field accelerates airborne particles towards an electrically grounded liquid surface, where they absorb. The air-liquid interface is fixated at the microscale pores of a perforated silicon diaphragm, each pore functioning as a static Laplace valve. Our system was experimentally tested using airborne smoke particles of ammonium chloride and aqueous salt solution as the liquid. We measured that EHD enhanced transport of the particles from the air into the liquid is enhanced over 130 times compared to passive trapping.