Tunable Particle Separation Through Acoustic Deterministic Lateral Displacement Micropillar Arrays

We propose a novel deterministic lateral displacement (DLD) microfluidic device that has the capability of tunable particle separation by utilizing acoustic vibration. In conventional DLD micropillar arrays, the critical diameter (D
c
,) which determines the trajectories ("displacement mode" or "zigzag mode") of a particle with a particular size, is fixed by the geometry of the arrays. To flexibly change the D
c
of the DLD micropillar arrays, we fabricated a DLD microfluidic device with piezoelectric transducers to induce the microstreaming around the micropillars by applying the acoustic vibration to the microfluidic device. By infusing the particle suspension and applying the acoustic vibration to the DLD micropillar arrays, we could confirm the characteristic flow patterns around the DLD micropillars and switch the separation mode of the model particles between displacement and zigzag mode. Our preliminary results could pave the way to actively tunable DLD separation.