Stretchable Inertial Microfluidic Device for Tunable Particle Separation

Abstract

Inertial microfluidics is a promising approach for particle separation due to the superior advantages of high throughput, simplicity, precise manipulation and low cost. However, the current obstacle of inertial microfluidics in biological applications is the broad size distribution of biological microparticles. Most devices only work well for a narrow range of particle sizes. For focusing and separating a new set of particles, troublesome and time-consuming design, fabrication, testing and optimization procedures are needed. As such, it is of particular interest to design a microfluidic device that can be tuned and adjusted to separate particles of various sizes. This paper reports on the proof of concept for a stretchable microfluidic device that can control the length via a stretching platform. By changing the channel dimensions, the device can be adapted to different particle sizes and flow rate ratios. We successfully demonstrate this approach with the separation of a mixture of 10 and 15-μm particles. Stretching the device significantly improves the focusing and separation efficiency of the specific particle sizes. We also show that there is an optimum stretch length, which results in the best separation performance. The proof of concept reported here is the first step towards designing stretchable inertial microfluidic devices that can be implemented for a wide range of biological and medical applications.

Computational Modelling and Big Data Analysis of Flow and Drug Transport in Microfluidic Systems: A Spheroid-on-a-Chip Study

“…Computational modelling enables systematic exploration of a large parameter space via in silico simulations aimed at the optimization of the design and operation of an MF device prior to experiments ( Enderling and Rejniak, 2013 ). In silico simulations have been extensively used for lab-on-a-chip platforms to simulate fluid flow and transport phenomena, including droplet formation ( Sontti and Atta, 2017 , 2020 ; Mohamed et al, 2019 ), micro-mixing ( Zhang et al, 2008 ; Suh and Kang, 2010 ), bacteria growth and culture ( Hohne et al, 2009 ; Westerwalbesloh et al, 2015 ; Kim et al, 2019 ; Kheiri et al, 2020 ), particle sorting and separation ( Han et al, 2015 ; Lu and Xuan, 2015 ; Amin Arefi et al, 2020 ; Fallahi et al, 2020 ), biomechanical forces ( Kim et al, 2015 ; Rousset et al, 2017 ), and drug delivery ( Hossain et al, 2012 ; Soltani and Chen, 2012 ; Soltani et al, 2016 ; d’Esposito et al, 2018 ). In the specific case of MF devices for cell biology studies, computational fluid dynamics (CFD) was used to investigate molecular transport in a bilayer membrane-based MF device and examine the effect of flow-induced shear stress on endothelial cells ( Wong et al, 2017 ).…”

Progress of Microfluidic Continuous Separation Techniques for Micro-/Nanoscale Bioparticles

“…Inertial particle focusing in a microchannel flow has tremendous potential for lab-on-a-chip applications due to its advantages of high throughput, simplicity, and external field-free and membrane-free operation, allowing continuous multiparticle separation based on the particle size [ 42 , 66 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 ]. The microfluidic channel profiles used in inertial microfluidics are largely divided into four groups: straight, spiral, sinusoidal, and sudden expansion channels.…”

A stretchable micromixer with enhanced performance for intermediate Reynolds numbers

“…We hypothesize that this improvement in mixing performance is attributed to the disturbance caused by the oscillation, as well as the dynamic changes of the microchannel dimensions. Under elongation, not only does the channel length increase, but the cross section also shrinks [41]. These rapid changes in the geometry of the stretchable micromixer induce disturbance to the ow, resulting in an improved mixing.…”

“…We recently proposed the concept for exible and stretchable micro uidics, which enables tunning the channel dimensions after their fabrication [41][42][43]. Stretchability allows for elongating the micro uidic channel in a desired manner and accordingly changing its dimensions.…”