New design for the separation of microorganisms using microfluidic deterministic lateral displacement

This paper presents a new design of microfluidic device for the separation of soft microorganisms using the deterministic lateral displacement principle. The novelty of the proposed design is based on creating new post shape that should address the challenges posed using the conventional circular post arrays. Based on experimental observations of trypanosome particles, circular posts have negative effects on the separation process of deformable and non-spherical cells. These effects reside in either shifting soft cells toward random streamlines further down the array or clogging the device. Airfoil and diamond post shapes have been proposed and compared against the circular posts. The flow around these posts has been simulated and analyzed numerically based on computational fluid dynamic (CFD). The results show that airfoil post shape has the potential to overcome complications when working with soft biological samples, namely the cells that are not rigid and not spherical. Microfluidic systems based on airfoil obstacles could easily be manufactured for clinical laboratory and biomedical applications providing a good promise in nano/micro-separation field. (C) 2010 Elsevier Ltd. All rights reserved.