Functional colloidal micro-sieves assembled and guided above a channel-free magnetic striped film

TL;DR

This paper introduces a novel magnetic micro-sieving technique that uses mobile domain walls to manipulate colloidal particles, enabling precise, reversible, and non-invasive operations in lab-on-a-chip devices.

Contribution

It presents a new method for fast, reversible micro-sieving using magnetic structured substrates and domain walls, advancing colloidal manipulation capabilities.

Findings

Enables precise movement and sieving of non-magnetic particles

Allows tweezer-like manipulation of microscopic cargos

Facilitates mechanical compression of dense colloidal layers

Abstract

Colloidal inclusions in lab-on-a-chip devices can be used to perform analytic operations in a non-invasive fashion. We demonstrate here a novel approach to realize fast and reversible micro-sieving operations by manipulating and transporting colloidal chains via mobile domain walls in a magnetic structured substrate. We show that this technique allows to precisely move and sieve non-magnetic particles, to tweeze microscopic cargos or to mechanically compress highly dense colloidal monolayers.