1. ICEEET’ 13
344
Design 0f Drug Delivery Systems in Lab on
Chip
I Abuthahir, Kalyani Vamsy B
Electronics and Communication Engineering, Anna University,
Chennai - 25, India.
Vamsy19@gmail.com
achin987@gmail.com
Abstract-We present a micro fluidic approach to
delivery of small quantity of drugs .The approach
is based on a two stage process of consecutive drug
dispensing and delivery, demonstrated by a device
featuring a fully planar design in which the micro
fluidic components are integrated in a single layer.
The design and simulation of the device will be
done using COMSOL 4.2a.This two dimensional
configuration offers ease in device fabrication and
it is compatible to various actuation schemes. A
compliance-based and normally closed check
value is used to couple the micro channels
responsible for drug dispensing and delivery.
Brief pneumatic pressure pulses are used to
mobilise buffer and drug solutions, which are
injected via a cannula into tissue. Thus the device
can potentially allow drug delivery and can also
be potentially extended to enable transdermal
drug delivery.
Keywords- Micro fluidic, Transdermal, Infuser,
Micro channels
INTRODUCTION
Bio mems:
Bio-MEMS is an abbreviation for
biomedical micro electromechanical systems.
With lab-on-a-chip (LoC) and bio-MEMS is
typically more focused on mechanical parts only
and micro fabrication technologies made suitable
for biological applications. While on the other
hand, lab-on-a-chip is concerned with
miniaturization and integration of laboratory
processes and experiments into single
(often micro fluidic) chips. In this definition, lab-
on-a-chip amendable to be adapted for
biological purposes.
Bio-MEMS can be used to refer to the
science and technology of operating at the micro
scale for biological and biomedical applications ,
which may or may not include any electronic or
mechanical functions. The interdisciplinary
nature of bio-MEMS combines material sciences,
clinical sciences, medicine, surgery, electrical
engineering, mechanical engineering, optical
engineering, chemical engineering, and biomedical
engineering. Some of its major applications
include genomics, proteomics, point-of-care
diagnostics, tissue engineering, and implantable
micro devices.
Microfluidics:
Microfluidics is defined as manipulation of the
working fluid by micro components as micro
pumps or micro valves based on pressure or
velocity. Microfluidics deals with the behaviour,
precise control and manipulation of fluids that are
geometrically constrained to a small, typically sub-
millimetre and micro scales.
LoC(Lab on Chip):
A lab-on-a-chip (LOC) is a device that integrates one
or several laboratory functions on a single chip of
only millimeters to a few square centimeters in size.
LOCs deal with the handling of extremely small
fluid volumes down to less than pico liters.
Lab-on-a-chip devices are a subset of
MEMS devices and often indicated by "Micro
Total Analysis Systems" (µTAS) as well. LoC is
closely related to, and overlaps with microfluidics
which describes primarily the physics, the
manipulation and study of minute amounts of fluids.
However, strictly regarded "Lab-on-a-Chip"
indicates generally the scaling of single or multiple
lab processes down to chip-format, whereas "µTAS"
is dedicated to the integration of the total sequence of
lab processes to perform chemical analysis. The
term "Lab-on-a-Chip" was introduced later on when
it turned out that µTAS technologies were more
widely applicable than only for analysis purposes.
It is an accurate way to introduce a set quantity of
fluid at a certain velocity to some piece of equipment.

2. ICEEET’ 13
345
This example involves the design of an infuser, a
device that feeds a reactor or analysis
TOOLS USED:
We use COMSOL 4.2a software to implement the
design of micro fluidics drug delivery system in
neurobiological studies.
METHODS USED:
I. INTRODUCTION:
Lab-on-a-chip devices have become quite popular for
analyses in fields such as biochemistry and
bioengineering. Through various techniques chemical
process such as chemical reactors, heat
exchangers, separators, and mixers with a specific
amount of fluid. Controlling pressure is an accurate
way to introduce a set quantity of fluid at a certain
velocity to some piece of equipment.
Flushing the equipment can also be important.
Optimizing such an infuser to maximize its use
would involve spending the least amount of time (and
fluid) flushing the equipment. Modeling this process
in the time domain can lead to an optimization of the
infusing pressure, micro channel design, and time
control.
This model demonstrates two useful tools in
COMSOL Multi physics modeling:
•
The ability to easily define a time-dependent
boundary condition
•
The ability to easily sweep meshes into 3D to save
memory
II. NAVIER -STOKES EQUATIONS:
This exercise arbitrarily sets the geometry
and conditions of the micro channel lab-on-a-chip
.The differential pressure at the two inlets relative to
the outlet pressure is time-controlled so that the inlet
flow passes from one to the next in a smooth way. At
any particular instant, one of the inlet flows
dominates, although flow could be significant from
more than one inlet. The pressure at the outlet is set
to zero.
The example models only fluid flow whose velocity
is of a magnitude that suggests laminar behavior.
This implies that you can get a numerical solution of
the full momentum balance and continuity equations
for incompressible flow with a reasonable number of
elements.
where ρ denotes density (kg/m3
), u is the velocity
(m/s), μ denotes dynamic viscosity (Pa·s), and p
equals pressure (Pa). The fluid in this case is water,
with the corresponding density and viscosity values.
III. DESIGN PROCEDURE:
MODEL WIZARD:
1. Go to the Model Wizard window.
2.Click Next.
3.In the Add physics tree, select Fluid Flow >
Single-Phase Flow > Laminar Flow (spf).
4. Click Add Selected.
5.Click Next.
6. Find the Studies subsection. In the tree, select
Preset Studies>Time Dependent.
7.Click Finish.
GEOMETRY 1
1. In the Model Builder window, click Model 1 >
Geometry 1.
2.Go to the Settings window for Geometry.
3.Locate the Units section. From the Length unit list,
choose μm.
4. Right-click Model 1 > Geometry 1 and choose
Work Plane
Rectangle 1
1.Right-click Model 1 > Geometry 1 and choose
Rectangle.
2. Go to the Settings window for Rectangle.
3 .Locate the Size section. In the Width edit field,
type 0.1.
4. In the Height edit field, type 0.2.
5 .Click the Build Selected button.
Bézier Polygon 1:

3. ICEEET’ 13
346
1. In the Model Builder window, right-click
Geometry 1 and choose Bézier Polygon.
2. Go to the Settings window for Bézier Polygon.
3.Locate the Polygon Segments section. Find the
Added segments subsection. Click the Add Linear
button.
4. Find the Control points subsection. In row 1, set x
to 0.1 and y to 0.2.
5.In row 2, set y to 0.2.
6 .Find the Added segments subsection. Click the
Add Linear button.
7 .Find the Control points subsection. In row 2, set y
to 0.575.
8. Find the Added segments subsection. Click the
Add Linear button.
9 .Find the Control points subsection. In row 2, set x
to 0.025.
10. Find the Added segments subsection. Click the
Add Linear button.
11. Find the Control points subsection. Click the
Close Curve button.
12.Click the Build Selected button.
13. Click the Zoom Extents button on the Graphics
toolbar.
Rectangle 2:
1. In the Model Builder window, right-click
Geometry 1 and choose Rectangle.
2 .Go to the Settings window for Rectangle.
3.Locate the Size section. In the Width edit field,
type 0.025.
4. In the Height edit field, type 1.025.
5 .Locate the Position section. In the y edit field, type
0.575.
6 .Click the Build Selected button.
7 .Click the Zoom Extents button on the Graphics
toolbar.
Mirror 1:
1. In the Model Builder window, right-click Model 1
> Geometry 1 > Work Plane 1 > Geometry and
choose Transforms > Mirror.
2 .Select the object b1 only.
3. Go to the Settings window for Mirror.
4. Locate the Input section. Select the Keep input
objects check box.
5. Click the Build Selected button.
Rectangle 3:
1. In the Model Builder window, right-click
Geometry 1 and choose Rectangle.
2 .Go to the Settings window for Rectangle.
3.Locate the Size section. In the Width edit field,
type 1.
4. In the Height edit field, type 0.1.
5 .Locate the Position section. In the x edit field, type
-0.03 and in the y edit field, type 1.6.
6 .Click the Build Selected button.
Rectangle 4:
1. In the Model Builder window, right-click
Geometry 1 and choose Rectangle.
2 .Go to the Settings window for Rectangle.
3.Locate the Size section. In the Width edit field,
type 0.1.
4. In the Height edit field, type 1.
5 .Locate the Position section. In the x edit field, type
-0.03 and in the y edit field, type 1.6.
6 .Click the Build Selected button.
Union 1 :
1.In the Model Builder window, right-click Model 1
> Geometry 1 > Work Plane 1 > Geometry and
choose Boolean Operations > Union.
2. Select the objects b1 and mir1 only.
3.Go to the Settings window for Union.

4. ICEEET’ 13
347
4. Locate the Union section. Clear the Keep interior
boundaries check box.
5.Click the Build Selected button.
Union diagram.
Extrude 1
1. In the Model Builder window, right-click Model
1>Geometry 1>Work Plane 1 and choose Extrude.
2. Go to the Settings window for Extrude.
3. Locate the Distances from Work Plane section. In
the table, enter 0.1 in distance box
4.Click the Build All button.
5. Click the Zoom Extents button on the Graphics
toolbar.
Extrude diagram
RESULTS:
MESHING PRESURE AND VELOCITY STUDY
PRESSURE RESULTS
The second default plot shows the surface of the
geometry with the pressure as a contour plot.
To create the plots in Figure 3 showing the velocity
in the x direction and the pressure at a point near the
outlet, perform the following steps:
1. In the Model Builder window, click
Results>Pressure (spf).
2. Go to the Settings window for 3D Plot Group.
3.Locate the Data section. From the Time list, choose
0.5.
4. Click the Plot button.
5 .Click the Zoom Extents button on the Graphics
toolbar.

5. ICEEET’ 13
348
OUTPUT GRAPH FOR PRESSURE
VELOCITY RESULTS
The velocity of the fluid in the block is given below
along with the arrow direction of the drug .The inlet 1
is provided with water and the other inlet is provided
with ink.
OUTPUT GRAPH FOR VELOCITY
CONCLUSION:
This project has a micro fluidic approach to drug
delivery for lab on chips. Aimed at addressing the
spatial and temporal requirements for drug delivery,
our approach is based on a two inlet design where
drug delivery is based on the principle consisting of
drug dispensing, in which a small amount of drug is
metered, and then drug delivery, in which the
measured drug is delivered within a brief time . This
approach was demonstrated by a inlet whereas to
regulate a unidirectional flow with minimum leakage
possible . This device is fully planar in that all micro
fluidic components are integrated in a single layer for
simple fabrication and integration with other
functional elements. The more pressure applied in the
inlet valve of the drug the velocity also increases.
REFERENCES

6. ICEEET’ 13
349
[1]www.comsol.com.
[2] Bin Wang, Junhui Ni, Yoav Litvin, Donald W.
Pfaff, and Qiao Lin,
“A Micro fluidic Approach to Pulsatile Delivery of
Drugs for Neurobiological Studies”, vol. 21, no. 1,
journal of micro electromechanical systems, 2012 .
[7] Aram J. Chung, Donn Kimb and David
Erickson, ” Electro kinetic micro -fluidic devices for
rapid, low power drug delivery in autonomous
Microsystems “, journal of The Royal Society of
Chemistry, 2007.
[3] P. K. Podder, D. P. Samajdar, D. Mallick and A.
Bhattacharyya
“ Design, Simulation and Study of Micro-pump,
Micro-valve and
Micro-needle for Biomedical Applications”, journal
of Institute of Radio Physics & Electronics,2012.
[4] Mr. Satyaprakash Narayan Das and Dr.
Gouranga Bose, “ Study of Fluid Dynamics and Heat
Transfer in MEMS Structures”, COMSOL
conference , 2012.
[5] Kollipara Sri Nithin , ”Analysis of Electro
osmotic Flow of Power Law Fluidics in Micro
Channel(1D)”,COMSOL conference ,2012.
[6] Tamal Dasa and Suman Chakraborty,
“Biomicrofluidics: Recent trends and future
challenges”, Sadhana journal 2009.
[7] Aram J. Chung, Donn Kimb and David
Erickson, ” Electro kinetic micro -fluidic devices for
rapid, low power drug delivery in autonomous
Microsystems “, journal of The Royal Society of
Chemistry, 2007.
[8] www.google.com .
[9] www.ieeeexplorer .com .
[10] www.wikipedia.com .
[11] Chaubey A, ”Mediated Biosensors ”,
Biosensors and Bioelectronics journal, 2002.