Particle focusing in a microchannel with acoustic metafluid

This work proposed a method of particle focusing by acoustic waves in a microfluidic channel with meta-structures. The channel was first filled by homogeneous metafluid possessing negative bulk modulus or density, mechanism and efficacy of particle focusing in such channel have been studied. Then as a realization, a structural microchannel composed of acoustic resonant elements has been proposed, which generated similar acoustic field gradient as that in homogeneous metafluid. Accordingly, particle movements in the structural microchannel were investigated and particle focusing was also achieved. The proposed particle focusing method is independent on the type of incident wave and microchannel's size.