Simulation of cell deformation in a microfluidic cross-slot
device
Citation for published version (APA):
Du, G., Fang, Q., & Toonder, den, J. M. J. (2008). Simulation of cell deformation in a microfluidic cross-slot
device. Poster session presented at Mate Poster Award 2008 : 13th Annual Poster Contest.
Document status and date:
Published: 01/01/2008
Document Version:
Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers)
Please check the document version of this publication:
• A submitted manuscript is the version of the article upon submission and before peer-review. There can be
important differences between the submitted version and the official published version of record. People
interested in the research are advised to contact the author for the final version of the publication, or visit the
DOI to the publisher's website.
• The final author version and the galley proof are versions of the publication after peer review.
• The final published version features the final layout of the paper including the volume, issue and page
numbers.
Link to publication
General rights
Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain
• You may freely distribute the URL identifying the publication in the public portal.
If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license above, please follow below link for the End User Agreement:
www.tue.nl/taverne
Take down policy
If you believe that this document breaches copyright please contact us at:
openaccess@tue.nl
providing details and we will investigate your claim.
SIMULATION OF CELL DEFORMATION IN
A MICROFLUIDIC CROSS-SLOT DEVICE
Guansheng Du1,2,3, Qun Fang2, Jaap den Toonder*1,3
1Eindhoven University of Technology, 2Zhejiang University, 3Philips Corporate Technologies
Polymer Technology
Mechanical Engineering Department
0 100 200 300 400 500 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Time/s Dx y
Computational results
We set a reference condition in our calculation, in which the inlet velocity is 10 mm/s, the liquid has density 1000 kg/m3 and viscosity 1 mPa·s the channel height and width are both 40 ȝm. We choose endothelial cell as our reference cell, whose radius is 7.5 ȝm, with elastic constants K1= 22.5 Pa, K2= 37.5 Pa, and viscosity Ș = 1.7 ×103Pa·s. [1] Both the cell and liquid are incompressible. The reference result is the red line in the following pictures.
Channel designs
Inlet velocity
Liquid viscosity
Cell types
Conclusion and future work
Substantial cell deformation can be obtained with use of the cross slot device. Currently, we are fabricating the cross slot designs to be used in future experiments of cell deformation.
[1] Sato, M., Ohshima N., Nerem R.M., J. of Biomech., 461-467, 29, 1996
[2] Lim C.T., Zhou E.H., Quek S.T., J. of Biomech., 195-216, 39, 2006 0 100 200 300 400 500 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 Time/s Dx y 0 100 200 300 400 500 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Time/s Dx y 0 100 200 300 400 500 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 Time/s Dx y
Figure 2: The deformation Dxyas a function of time for six different designs. Design 1-4 are on the basis of structure A, but the channel width are 100 ȝm (green), 80 ȝm (black), 40 ȝm (red), 30 ȝm (blue) respectively. Design 5 (yellow) and 6 (pink) are structure B and C respectively.
Figure 3: The deformation Dxyas a function of time for five different inlet velocities, v = 2 mm/s (yellow), 4 mm/s (green), 6 mm/s (black), 8 mm/s (blue), 10 mm/s (red).
Figure 4: The deformation Dxyas a
function of time for five different liquid viscosities ȘLiquid= 1 mPa·s (red), 3 mPa·s
(green), 5 mPa·s (black), 7 mPa·s (blue), 10 mPa·s(yellow).
Figure 5: The deformation Dxyas a
function of time for six different cell types, endothelial cells (red), fibroblasts (green), chondrocytes (black), chondrocyte nuclei (yellow), rat osteosarcoma cells (pink), bovine chondrocytes (blue). [2]
Introduction
It is well known that a number of serious diseases affect the mechanical properties of cells, e.g. cancer, malaria, cardiac myopathy). The ability to measure cell mechanical properties, therefore, could provide a good diagnosis method. We propose a special microfluidic device, in which a fluid flow provides the hydrodynamic force that deforms the cells. The measurement of the extent of deformation enables to estimate the cell stiffness. The aim of our study is to investigate the effectiveness of approach, and to obtain an optimized design of the cross-slot geometry.
The device priciple
Our basic microfluidic device is a cross-slot device. It contains two fluid inlets and two fluid outlets. A cell is positioned at the center and fixed there by continuous control of the pressures at the two inlets. The cell experiences an elongational flow that deforms it.
Computational methods
We carried out finite element method software Comsol to calculate the pressure and stress distribution around the cell boundary at different conditions. The solution was then transformed to MATLAB, in which the cell deformation was calculated as a standard linear solid [1]. To quantify the deformation, we use the so-celled Taylor deformation parameter:
where the Xtand Yt are the cell radius in the X-direction and
Y-direction, which are time-dependent.
The channel structures (Fig.1) are based on the cross-slot. To obtain better cell deformation and cell control results, two improved structures were also investigated.
Figure 1: The cross slot designs used in the simulation. Design A:
channel width and height are both 40 ȝm. Design B: the width is 50 ȝm, which is gradually narrowed to 15 ȝm in the x-direction and to 30 ȝm in the y-direction. Design C: channel width is 50 ȝm, narrowed to 15 ȝm in the x-direction, and the outlet channels in the y-direction contain obstructions.
t t xy t t Y X D Y X
Introduction
It is well known that a number of serious diseases affect the mechanical properties of cells, e.g. cancer, malaria, cardiac myopathy). The ability to measure cell mechanical properties, therefore, could provide a good diagnosis method. We propose a special microfluidic device, in which a fluid flow provides the hydrodynamic force that deforms the cells. The measurement of the extent of deformation enables to estimate the cell stiffness. The aim of our study is to investigate the effectiveness of approach, and to obtain an optimized design of the cross-slot geometry.
The device priciple
Our basic microfluidic device is a cross-slot device. It contains two fluid inlets and two fluid outlets. A cell is positioned at the center and fixed there by continuous control of the pressures at the two inlets. The cell experiences an elongational flow that deforms it.
Computational methods
We carried out finite element method software Comsol to calculate the pressure and stress distribution around the cell boundary at different conditions. The solution was then transformed to MATLAB, in which the cell deformation was calculated as a standard linear solid [1]. To quantify the deformation, we use the so-celled Taylor deformation parameter:
where the Xtand Yt are the cell radius in the X-direction and
Y-direction, which are time-dependent.
The channel structures (Fig.1) are based on the cross-slot. To obtain better cell deformation and cell control results, two improved structures were also investigated.
Figure 1: The cross slot designs used in the simulation. Design A:
channel width and height are both 40 ȝm. Design B: the width is 50 ȝm, which is gradually narrowed to 15 ȝm in the x-direction and to 30 ȝm in the y-direction. Design C: channel width is 50 ȝm, narrowed to 15 ȝm in the x-direction, and the outlet channels in the y-direction contain obstructions.
t t xy t t Y X D Y X
