Tunable particle separation via deterministic absolute negative mobility

TL;DR

This paper presents a tunable particle separation method using negative mobility in a periodic potential, enabling size-based sorting of particles with potential applications in biomedical and industrial fields.

Contribution

It introduces a novel separation technique exploiting negative mobility, allowing control over particle size separation by adjusting external force parameters.

Findings

Negative mobility enables particles to move opposite to the applied force.

Separation efficiency can be tuned by varying external force parameters.

The method is promising for point-of-care lab-on-a-chip devices.

Abstract

Particle isolation techniques are in the spotlight of many areas of science and engineering. In food industry, a harmful bacterial activity can be prevented with the help of separation schemes. In health care, isolation techniques are used to distinguish cancer and healthy cells or in therapy for Alzheimer's and Parkinson's diseases. We consider a cloud of Brownian particles of different sizes moving in a periodic potential and subjected to an unbiased driving as well as a constant force. We reveal an efficient separation strategy via the counterintuitive effect of negative mobility when particles of a given size are transported in a direction opposite to the applied constant force. We demonstrate a tunable separation solution in which size of the particle undergoing separation may be controlled by variation of the parameters of the external force applied to the system. This approach is an important step towards the development of point-of-care lab-on-a-chip devices.