Template-Free Preparation of Thermoresponsive Mag-netic Cilia Compatible with Biological Conditions

TL;DR

This paper introduces a novel, template-free method for creating thermoresponsive magnetic cilia that are compatible with biological conditions, enabling flexible and dense arrays for fluid manipulation.

Contribution

It presents a new physicochemical approach using temperature-triggered reversible assembly of coated iron oxide nanoparticles to fabricate magnetic cilia without templates.

Findings

Cilia lengths tunable between 10 and 100 microns

Dense arrays with aspect ratios up to 100

Stable magnetic actuation over several hours

Abstract

Bio-inspired materials are commonly used in the development of functional devices. The fabrication of artificial cilia mimicking the biological functions has emerged as a promising strategy for fluid manipulation in miniaturized systems. In this study, we propose a different physicochemical insight for the preparation of magnetic cilia based on the temperature-triggered reversible assembly of coated iron oxide nanoparticles in a bio-compatible template-free approach. The length of the prepared cilia could be tuned between 10 and 100 microns reaching aspect ratios up to 100 in a very dense array of flexible structures with persistence lengths around 8 microns. Magnetic actuation of the cilia revealed robust structures (over several hours of actuation) with a wide range of bending amplitudes resulting from high susceptibility of the filaments. The results demonstrate that the proposed strategy is an efficient and versatile alternative for templated fabrication methods and producing cilia with remarkable characteristics and dimensions within the template-free approaches.