Tunable Particle Separation Using Vibration Induced Flow in Deterministic Lateral Displacement Micropillar Arrays

We propose a novel tunable particle separation technique based on a deterministic lateral displacement (D LD) micropillar array using vibration induced microstreaming. In conventional DLD separation, the trajectories of a particle (“displacement mode” or “zigzag mode”) with a certain size are determined by the critical diameter <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$D_{\mathrm{c}}$</tex>, which is fixed by the geometry of the micropillar arrays. To flexibly change the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$D_{\mathrm{c}}$</tex> without redesigning the DLD devices, we developed and demonstrated a method for switching particle trajectories using microstreaming generated by vibration. By introducing the particles suspension and applying vibration to the DLD array, we could produce the characteristic flow patterns around the micropillars and dynamically switch the separation mode of model particles (e.g. microbeads, blood) between displacement and zigzag mode.