Capturing Polar and Nonpolar Particles with an Electroadhesive Device Using Interfacial and Orientational Polarization

Many air filtration technologies have been used to solve the environmental issues of fine and ultrafine dust particles, which have been raised over the past decades. Many other filtration technologies have been developed, while high-efficiency particulate arrestance (HEPA) is widely used recently due to its high efficiency. However, the HEPA filter has some limitations, such as high pressure drop, nonrecyclability, and most importantly, short lifetime. Regarding other types of air filters, electrostatic filters require a two-stage process (i.e., charging and polarization) of particles before filtration, whereas electroadhesion air filters could capture both polar and nonpolar particles without a two-stage process. The dust-holding capacity allows the quantitative analysis of the areal adhesion amount to be conducted. In this study, three different kinds of particles of fine dust, microcrystalline cellulose, and Teflon were tested. A model equation of the areal adhesion amount was also developed as a function of boundary edge length, voltage, and the dielectric constant of each material and allowed the areal adhesion amount of fine dust particles to be maximized, which is well above those of the HEPA filter and electrostatic filter. The optical images clearly showed that the dielectric polarization of polar particles was stronger than that of nonpolar particles.