Deterministic radial displacement: modular, reconfigurable, and reusable

Abstract

Deterministic lateral displacement (DLD) is an effective method of microparticle separation that has always been constructed of monolithic arrays of obstacles. By cylindrically revolving the 2D geometry through a complete circle, deterministic radial displacement (DRD) devices can be fabricated in segments and assembled without constraints on axial rotation. In contrast to prior work, this enables a reusable and reconfigurable system that represents a genuine step forward for DLD usability. It is not known how the critical particle size changes for strongly curved DLD geometries. We use COMSOL simulations of 2D and cylindrically swept geometries to show that the critical size changes slightly depending on curvature. We use low-cost resin 3D printing to build and test a scale version of a DRD device with a nominal critical size of 134 μm. The experimental device enriches particles between 134 and 200 μm by an average of fourfold. The DRD device is disassembled, cleaned, and reused 3 times, with one in 10 segments replaced each time. Advances in 3D printing technology will reduce the critical size and increase the durability of future DRD systems. This will make the modular, reusable, and high throughput DRD system highly attractive for a wide range of sample prep and purification applications.