Microfluidics Software - For Simulating Microfluidics Devices.pdf

7/24/2019 Microfluidics Software - For Simulating Microfluidics Devices.pdf

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Microuidic Module

oware for Mulphic imulaon of Microuidic Device

An ink droplet i ejected through a nozzle and travel through air until it hit the target. The model can e ued to

undertand the effect of the ink propertie and the preure profile at the nozzle on the drop velocit, drop volume,

and the preence of atellite drop.

General-Purpoe Microuidic imulaon

The Microfluidic Module ring ou eail-operated tool for tuding microfluidic device.

Important application include imulation of la-on-a-chip device, digital microfluidic,

electrokinetic and magnetokinetic device, and inkjet. The Microfluidic Module include read

to-ue uer interface and imulation tool, o called phic interface, for ingle-phae flow,

porou media flow, two-phae flow, and tranport phenomena.

caling Down to Microcale Flow


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Microfluidic flow occur on length cale that are order of magnitude maller than macrocopic

flow. Manipulation of fluid at the microcale ha a numer of advantage tpicall

microfluidic tem are maller, operate fater, and require le fluid than their macrocopic

equivalent.

nerg input and output are alo eaier to control (for example, heat generated in a chemical

reaction) ecaue the urface-to-area volume ratio of the tem i much greater than that of a

macrocopic tem. In general, a the length cale of the fluid flow i reduced, propertie thatcale with the urface area of the tem ecome comparativel more important than thoe tha

cale with the volume of the flow.

Thi i apparent in the fluid flow itelf a the vicou force, which are generated hear over

the iovelocit urface, dominate over the inertial force. The Renold numer (Re) that

characterize the ratio of thee two force i tpicall low, o the flow i uuall laminar. In

man cae, the creeping (toke) flow regime applie (Re1). Laminar and creeping flow make

mixing particularl difficult, o ma tranport i often diffuion limited, ut even in microfluidic

tem diffuion i often a low proce. Thi ha implication for chemical tranport within

microfluidic tem. The Microfluidic Module i deigned pecificall for handling momentum

heat, and ma tranport with pecial conideration for fluid flow at the microcale.

View creenhot

Addional image:

LAMLLA MIXR: The picture how flow in a device deigned to enhance the mixing of two fluid in

lamella flow. Preure contour are hown on the wall of the mixer, and the velocit magnitude i

hown at the inlet and outlet of the mixer a well a at the point where the two et of channel

(carring different fluid) converge. treamline (in red) are alo plotted. The inet how the

concentration of a diffuing pecie preent in onl one of the fluid. It i plotted along vertical linelocated progreivel further down the center of the mixer.

LCTROWTTING LN: The figure aove how an adjutale focu liquid len, whoe radiu of

curvature can e adjuted uing the electrowetting effect. The color how the fluid velocit

magnitude in a lower, oil-filled part of the len, while the arrow plot how the velocit in the liquid

aove the oil len.

PLIT AND RCOMIN MIXR NCHMARK: Thi example model a plit and recomine mixer

channel in which a tracer fluid i introduced and mixed multi-lamination. Diffuion i removed from

the model uing an extremel low diffuion coefficient o that an numerical diffuion can e tudied
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in the lamination interface. The reult compare well with the referenced pulication in oth the

lamination pattern and total preure drop acro the mixer.

TWO-PHA FLOW: When multiple phae are preent, urface tenion effect ecome important

relative to gravit and inertia at mall length cale. The Laplace preure (the preure jump acro a

two-phae oundar), capillar force, and Marangoni force all cale a 1/Length. The figure elow

how the reak-up of oil droplet to produce an emulion a the oil flow into a channel carring a

econd fluid. Velocit treamline are hown and the fluid velocit i plotted on the mmetr plane.

The two-phae oundar i hown in green.

COMOL DKTOP: A complete modeling project from tart to finih can e accomplihed within the

COMOL Dektop . The viualization how a time-dependent ingle-phae flow tud of a

microchannel that i ued to infue and fluh another piece of equipment with a fluid.

LCTROOMOTIC MIXR: Thi particular micromixer take advantage of electroomoi to mix

fluid. A time-dependent electric field i applied, and the reulting electroomoi pertur the flow. A

treamline viualization how extenive folding and tretching of the flow field.

COMOL general-purpoe multiphic feature are uniquel uited for handling the man

microcale effect that are utilized in microfluidic device. It i ea to et up coupled

electrokinetic and magnetodnamic imulation including electrophorei, magnetophorei,

dielectrophorei, electroomoi, and electrowetting. In addition, chemical diffuion and

reaction for dilute pecie functionalit included in the module enale ou to imulate

procee occurring in la-on-a-chip device. For imulating rarefied ga flow, ou can ue the

pecialized oundar condition that activate flow imulation in the lip flow regime. The

Microfluidic Module alo provide dedicated method for imulation of two-phae flow with

the level et, phae field, and moving meh method. For each of thee, the capailitie of the

Microfluidic Module include urface tenion force, capillar force, and Marangoni effect.

View creenhot

Workow for Modeling Microuidic Device

To model a microfluidic device, ou egin defining the geometr in the oftware importin

a CAD file or via the geometr modeling tool that are uilt into COMOL Multiphic. For

importing geometr model, everal choice are availale to ou: the CAD Import Module, for

import of mechanical CAD model; the CAD Import Module for import of electronic laout;

and the LiveLink product for CAD for a direct link to model created in a dedicated CAD

oftware package. In the next tep, ou elect appropriate fluid propertie and chooe a uitale

phic interface. Initial condition and oundar condition are et up within the interface.

Next, ou define the meh. In man cae, COMOL automaticall created default meh, whic

i produced from phic-dependent default, will e appropriate for the prolem. A olver i

elected, again with default appropriate for the relevant phic, and the prolem i olved.
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Finall, ou can viualize the reult.You acce all of thee tep from the COMOL Dektop .

The Microfluidic Module can olve for tationar and time-dependent flow in 2D and 3D, and

can e coupled with an other add-on product for further extenion of the modeling

capailitie. One uch example i for tracking particle releaed in the flow tream, which i

made poile comining with the Particle Tracing Module.

View creenhot

ingle-Phae Flow

The Fluid Flow interface ue phical quantitie, uch a preure and flow rate, and phical

propertie, like vicoit and denit, to define a fluid-flow prolem. The phic interface for

laminar flow cover incompreile and weakl compreile flow. Thi Fluid Flow interface

alo allow for imulation of non-Newtonian fluid flow. A phic interface for creeping flow i

ued when the Renold numer i ignificantl le than 1. Thi i often referred to a toke

flow and i appropriate for ue when vicou flow i dominant. It i uuall applicale to

microfluidic device.

View creenhot

Two-Phae Flow

Three different method are availale for two-phae flow: level-et, phae-field, and moving

meh method. Thee are ued to model two fluid eparated a fluid interface and where the

moving interface i tracked in detail, including urface curvature and urface tenion force. The

level-et and phae-field method ue a fixed ackground meh and olve additional equation

to track the interface location. The moving meh method olve the flow equation on a moving

meh with oundar condition to repreent the fluid interface. In thi cae, additional equation

are olved for the meh deformation mean of the aritrar Lagrangian-ulerian (AL)

method. All of thee method and their phic interface upport oth compreile and

incompreile laminar flow, where one or oth fluid can e non-Newtonian.

View creenhot

Rareed Flow

Rarefied ga flow occur when the mean free path of the molecule ecome comparale with

the length cale of the flow. The Knuden numer, Kn, characterize the importance of

rarefaction effect on the flow. A the ga ecome rarefied (correponding to increaing

Knuden numer), the Knuden laer, which i preent within one mean free path of the wall,

egin to have a ignificant effect on the flow. For Knuden numer elow 0.01, rarefaction

can e neglected and the laminar flow phic interface of the Microfluidic Module can e
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ued with non-lip oundar condition. For lightl rarefied gae (0.01


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The manipulation of contact angle the electrowetting phenomena i alo ea in microcale

device. lectrowetting i a phenomenon that ha een exploited a a ai for variou new

dipla technologie. The Microfluidic Module allow for direct manipulation of the contact

angle with uer-defined expreion including voltage parameter.

View creenhot

Ma Tranport

The Microfluidic Module provide a dedicated phic interface for tranport of diluted pecie

It i ued to imulate chemical pecie tranport through diffuion, convection (when coupled to

fluid flow), and migration in electric field for mixture where one component a olvent i

preent in exce (90 mol% or greater). It i tpicall emploed to model the performance of

mixer. For modeling chemical reaction in microfluidic device, ou can comine the

Microfluidic Module with the Chemical Reaction ngineering Module, which alo make

availale tranport of concentrated pecie with inar diffuion.

Flexile and Rout Microuidic imulaon Plaorm

For each of the Microfluidic interface, the underling phical principle are expreed in the

form of partial differential equation, together with correponding initial and oundar

condition. COMOL deign emphaize the phic providing ou with the equation

olved each feature and offering ou full acce to the underling equation tem. There i

alo tremendou flexiilit to add uer-defined equation and expreion to the tem. For

example, to model the tranport of a pecie that ignificantl affect the vicoit of the fluid,impl tpe in concentration-dependent vicoit no cripting or coding i required. When

COMOL compile the equation, the complex coupling generated thee uer-defined

expreion are automaticall included in the equation tem. The equation are then olved

uing the finite element method and a range of indutrial-trength olver. Once a olution i

otained, a vat range of potproceing tool are availale to interrogate the data, and

predefined plot are automaticall generated to how the device repone. COMOL offer the

flexiilit to evaluate a wide range of phical quantitie, including predefined quantitie uch a

the preure, velocit, hear rate, or the vorticit (availale through ea-to-ue menu), andaritrar uer-defined expreion

Interfacing with xcel and MATLA

You can comine the Microfluidic Module with Microoft xcel via LiveLink for xcel . Thi

LiveLink product add a COMOL ta and pecialized toolar to the xcel rion for

controlling the parameter, variale, and meh, or for running a imulation. It alo include the
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capailit to import and export xcel file for parameter and variale lit in the COMOL

Dektop .

If ou wih to drive COMOL imulation mean of cript programming, ou can ue

MATLA and COMOL together through the interface provided the LiveLink forMATLA

With thi LiveLink , ou can acce all the functionalit of the COMOL Dektop from a

wealth of MATLA command. Thi provide a programmatic alternative to uing the COMOL

Dektop for microfluidic imulation.

Microfluidics Software - For Simulating Microfluidics Devices.pdf

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