**3. Analysis and modeling for microchannel**

#### **3.1. Sieve or lattice type microchannel network design**

The sieve-shaped micro channel network is assured of two types of microchannels (I) The main channel and (II) Separation channel, In microchannel main channels are deeper than the separation channels as the main channels are at different angle positions of channel to lower right/left and perpendicularly-crossing are separation channels. Particle/cell is introduced continuously from the inlet at intervals, whereas a buffer solution without particles/ cell is introduced from two side inlets shown in **Figures 6**–**8**. Smaller particles can reach the ceiling (upper region) of the main channels but the larger particles cannot because of the effect of hydrodynamic filtration. Consequently the repetition of the larger particles entering the separation channels will be higher than that of the smaller particles and the positions of the larger particles will shift in the direction according to flow rate more greatly than those of the smaller particles depending on the mass and size of the particle achieving continuous separation [21].

As discussed about the techniques employing the effect of hydrodynamics in microfluidic applications has been prominent in the decades to be fruitful in terms of efficiency, throughput and continues to develop in the future through some more improvements in separation processing rate and resolution. However there are many other new areas of hydrodynamic microfluidic phenomena for an application which demand further investigations and promisingly both explain and informs researchers theoretically about basics on physics and

to exploit them experimentally in applications of biological terms. In spite of a few active separation techniques have been developed to conform the demand growing in these new area [22]. Presently a continuous particle/cell separation system utilizes a Sieve type-shaped micro channel network has been shown ahead. The difference in the densities, velocity, pressure and viscosity in sample it generates the asymmetric and symmetric flow distribution at each intersection with intervals resulting in the separation of large size particles through the streamline [23]. A modified mechanism of particle sorting using sieve type microchannel patterning is presented where it potentially enables the throughput separation highly and can prevent clogging problem of micro channel at some extent. The presented system would become a simple but valuable unit operation in the microfluidic apparatus for medical and biological experiments [21]. The presented network system would be highly useful because of sorting microparticles and cells with a high precision and would become an important useful

Micropatterning in BioMEMS for Separation of Cells/Bioparticles

http://dx.doi.org/10.5772/intechopen.76060

79

**Figure 8.** Schematic of: (a) Symmetric hydrodynamic flow focusing and (b) Asymmetric hydrodynamic flow focusing

tool for general chemical/ biological experiments in laboratories.

**Figure 7.** Schematic of Sieve type – shaped Microchannel network.

[27].

**Figure 6.** Hydrodynamic filtration principle showing behavior of particle at branch point according to different flow rates which are high, medium and low at multiple channels [19].

**Figure 7.** Schematic of Sieve type – shaped Microchannel network.

**3. Analysis and modeling for microchannel**

78 MEMS Sensors - Design and Application

**3.1. Sieve or lattice type microchannel network design**

separation [21].

The sieve-shaped micro channel network is assured of two types of microchannels (I) The main channel and (II) Separation channel, In microchannel main channels are deeper than the separation channels as the main channels are at different angle positions of channel to lower right/left and perpendicularly-crossing are separation channels. Particle/cell is introduced continuously from the inlet at intervals, whereas a buffer solution without particles/ cell is introduced from two side inlets shown in **Figures 6**–**8**. Smaller particles can reach the ceiling (upper region) of the main channels but the larger particles cannot because of the effect of hydrodynamic filtration. Consequently the repetition of the larger particles entering the separation channels will be higher than that of the smaller particles and the positions of the larger particles will shift in the direction according to flow rate more greatly than those of the smaller particles depending on the mass and size of the particle achieving continuous

As discussed about the techniques employing the effect of hydrodynamics in microfluidic applications has been prominent in the decades to be fruitful in terms of efficiency, throughput and continues to develop in the future through some more improvements in separation processing rate and resolution. However there are many other new areas of hydrodynamic microfluidic phenomena for an application which demand further investigations and promisingly both explain and informs researchers theoretically about basics on physics and

**Figure 6.** Hydrodynamic filtration principle showing behavior of particle at branch point according to different flow

rates which are high, medium and low at multiple channels [19].

to exploit them experimentally in applications of biological terms. In spite of a few active separation techniques have been developed to conform the demand growing in these new area [22]. Presently a continuous particle/cell separation system utilizes a Sieve type-shaped micro channel network has been shown ahead. The difference in the densities, velocity, pressure and viscosity in sample it generates the asymmetric and symmetric flow distribution at each intersection with intervals resulting in the separation of large size particles through the streamline [23]. A modified mechanism of particle sorting using sieve type microchannel patterning is presented where it potentially enables the throughput separation highly and can prevent clogging problem of micro channel at some extent. The presented system would become a simple but valuable unit operation in the microfluidic apparatus for medical and biological experiments [21]. The presented network system would be highly useful because of sorting microparticles and cells with a high precision and would become an important useful tool for general chemical/ biological experiments in laboratories.

**Figure 8.** Schematic of: (a) Symmetric hydrodynamic flow focusing and (b) Asymmetric hydrodynamic flow focusing [27].

Here two inlets are employed from which one is used to introduce fluid without containing particles so that the particles flow along the sidewall. Multiple side channels are used in area so that particles larger than a certain size cannot pass through. As a result, such particles are concentrated and focused onto the sidewall. Microchannel network can be as shown in figure using COMSOL Multiphysics 5.2a software. In the downstream area the side channels are made gradually wider or shorter so that the particles are removed from the main stream in ascending order of size. Thus, the particles are sorted by size and concentrated with cytometry of flow with a basic laminar flow that focuses particles in same dimension, while at High flow rate inertial forces on particles cause are used to manipulate particles and inertial forces dominates when the particles Reynolds number is >1.

It is well known that a microchannel acts as a resistive circuit when an incompressible Newtonian fluid is continuously introduced into the channel. The micro device was therefore designed according to the concept that the volumetric flow rate *Q*, applied pressure *P*, and hydrodynamic resistance *R* are analogs of *I*, *V* and *R* in Ohm's law, respectively. In this study the following equation was used to estimate the hydrodynamic resistance *R* of each segment of the microchannel [24].

$$R \ll \frac{L}{l\_i^3 l\_2} \left[ 1 - \frac{192}{\pi^3 l\_2} \sum\_{\nu=1,3,5}^{\infty} \frac{\tanh\{\nu^{\nu} l\_2 \psi\}}{n^s} \right]^{-1} \tag{1}$$

where KBT is thermal energy at temperature, D is diffusion coefficient of particle of radius 'a'

In this sieve type-shaped design a single region of posts will have a single threshold and particle flow will be in two directions. According to the principle of mass conservation, the supply of fluid flow passing through the dimension of the stream should be equal to the fluid

> *Qi* ¯

Moreover, the total fluid flowing through the outlet channel must equal the total amount of

<sup>=</sup> \_\_\_\_\_\_\_\_\_\_\_ *Qi γ*(*Qi* + *Qs*<sup>1</sup>

> *νf* \_\_ ¯ *νo*

average flow velocities in the focusing stream and the outlet, respectively shown in **Figure 6**

Thus the performance of the device using sieve type-shaped microchannel can be improved with the faster flow rate and clogging problem can be reduced. A critical hydrodynamic diameter can be designed easily with G between posts of the microchannel shown in **Figure 9**. Some

**1.** Flow within the micro channels is steady and laminar. But, because of the smaller charac-

**3.** The fluid has constant density in the inlet channel, side channels and outlet channel.

teristic dimensions are involved the flow in microchannel is laminar.

**4.** Inlet, outlet and all the channels are of the same measurement.

is width of the outlet channel and vf

*<sup>ν</sup><sup>o</sup>* <sup>=</sup> *Qi* <sup>+</sup> *Qs*<sup>1</sup> <sup>+</sup> *Qs* \_\_\_\_\_\_\_\_\_<sup>2</sup>

Therefore, the relation between the width of the hydrodynamic focused stream (wf

*wo*

*vf <sup>h</sup>* (4)

Micropatterning in BioMEMS for Separation of Cells/Bioparticles

http://dx.doi.org/10.5772/intechopen.76060

*wo* <sup>×</sup> *<sup>h</sup>* (5)

) and the side channels (Qs1 and Qs2) can be as

<sup>+</sup> *Qs*2) (6)

) and the

81

and v<sup>o</sup>

are the

inflow that we wish to separate from flow streamlines.

passing through the inlet channel, i.e. [27]

¯

*wf* \_\_\_

[27].

where,

[27].

volumetric flow rates of the inlet channel (Q<sup>i</sup>

*<sup>γ</sup>* <sup>=</sup> ¯

where the velocity ratio γ to be found, w<sup>o</sup>

assumptions on this study were made are:

**2.** The fluids are Newtonian.

*wf* <sup>=</sup> \_\_\_

fluid supplied from the inlet and side channels, i.e. [27]

where *l* 1 and *l* 2 are either the width or depth of the microchannel however, *l* 1 is the larger of these two values.

#### **3.2. Theoretical and numerical analysis**

For theoretical discussion prediction made with the width of two-dimensional hydrodynamically streams in rectangular shape micro channels is designed. Here critical diameter of bacteria particles will sustain a stable detonation for minimum diameter while the spacing that is center to center between the post is known as λ and d is known as the relative shift between adjacent posts, thus to measure the parameter λ ¸t can be measure with relative shift and tangent of the angle with respect to the vertical objects through the array as shown in (**Figure 8**) [25].

$$
\varepsilon = \frac{d}{\lambda} \tag{2}
$$

"Unconfined" and "confined" critical diameter was determined directly by inspecting the experimental distance/time data and examining the lattice-shaped microchannel at different angle [26].

Generally, ε (smaller) gives an result for smaller critical size in an array. However the clogging problem and large particle densities in an array do not occur easily. Therefore for a simple object [25],

$$D = \frac{K\_y T}{6 \prod \eta a} \tag{3}$$

where KBT is thermal energy at temperature, D is diffusion coefficient of particle of radius 'a' inflow that we wish to separate from flow streamlines.

In this sieve type-shaped design a single region of posts will have a single threshold and particle flow will be in two directions. According to the principle of mass conservation, the supply of fluid flow passing through the dimension of the stream should be equal to the fluid passing through the inlet channel, i.e. [27]

$$w\_f = \frac{Q\_i}{\overline{v\_f}h} \tag{4}$$

Moreover, the total fluid flowing through the outlet channel must equal the total amount of fluid supplied from the inlet and side channels, i.e. [27]

$$\nabla\_o = \frac{Q\_i + Q\_{\ast\_i} + Q\_{\ast\_i}}{w\_o \star h} \tag{5}$$

Therefore, the relation between the width of the hydrodynamic focused stream (wf ) and the volumetric flow rates of the inlet channel (Q<sup>i</sup> ) and the side channels (Qs1 and Qs2) can be as [27].

$$\frac{w\_f}{w\_s} = \frac{Q\_i}{\gamma (Q\_i + Q\_{s\_i} + Q\_{s\_i})} \tag{6}$$

where,

Here two inlets are employed from which one is used to introduce fluid without containing particles so that the particles flow along the sidewall. Multiple side channels are used in area so that particles larger than a certain size cannot pass through. As a result, such particles are concentrated and focused onto the sidewall. Microchannel network can be as shown in figure using COMSOL Multiphysics 5.2a software. In the downstream area the side channels are made gradually wider or shorter so that the particles are removed from the main stream in ascending order of size. Thus, the particles are sorted by size and concentrated with cytometry of flow with a basic laminar flow that focuses particles in same dimension, while at High flow rate inertial forces on particles cause are used to manipulate particles and inertial forces

It is well known that a microchannel acts as a resistive circuit when an incompressible Newtonian fluid is continuously introduced into the channel. The micro device was therefore designed according to the concept that the volumetric flow rate *Q*, applied pressure *P*, and hydrodynamic resistance *R* are analogs of *I*, *V* and *R* in Ohm's law, respectively. In this study the following equation was used to estimate the hydrodynamic resistance *R* of each segment

dominates when the particles Reynolds number is >1.

*l* 1 3 *l* 2 [

<sup>1</sup> <sup>−</sup> <sup>192</sup> *<sup>l</sup>* \_\_\_\_1 *π*<sup>5</sup> *l* 2 ∑ *n*=1,3,5

are either the width or depth of the microchannel however, *l*

For theoretical discussion prediction made with the width of two-dimensional hydrodynamically streams in rectangular shape micro channels is designed. Here critical diameter of bacteria particles will sustain a stable detonation for minimum diameter while the spacing that is center to center between the post is known as λ and d is known as the relative shift between adjacent posts, thus to measure the parameter λ ¸t can be measure with relative shift and tangent of the

"Unconfined" and "confined" critical diameter was determined directly by inspecting the experimental distance/time data and examining the lattice-shaped microchannel at different angle [26]. Generally, ε (smaller) gives an result for smaller critical size in an array. However the clogging problem and large particle densities in an array do not occur easily. Therefore for a simple

angle with respect to the vertical objects through the array as shown in (**Figure 8**) [25].

<sup>∞</sup> tanh(*<sup>n</sup> <sup>l</sup>* <sup>2</sup> ⁄2 *<sup>l</sup>* \_\_\_\_\_\_\_1) *n*<sup>5</sup> ]

−1

(1)

is the larger of

1

*<sup>λ</sup>* (2)

<sup>6</sup>∏*<sup>a</sup>* (3)

of the microchannel [24].

80 MEMS Sensors - Design and Application

where *l* 1 and *l* 2

object [25],

these two values.

*<sup>R</sup>* <sup>∝</sup> \_\_\_*<sup>L</sup>*

**3.2. Theoretical and numerical analysis**

*ε* = \_\_*<sup>d</sup>*

*<sup>D</sup>* <sup>=</sup> *KB <sup>T</sup>* \_\_\_\_\_

$$\gamma' = \frac{\overline{v}\_f}{T\_o}$$

where the velocity ratio γ to be found, w<sup>o</sup> is width of the outlet channel and vf and v<sup>o</sup> are the average flow velocities in the focusing stream and the outlet, respectively shown in **Figure 6** [27].

Thus the performance of the device using sieve type-shaped microchannel can be improved with the faster flow rate and clogging problem can be reduced. A critical hydrodynamic diameter can be designed easily with G between posts of the microchannel shown in **Figure 9**. Some assumptions on this study were made are:


However instead of rectangle type shape in microchannel there are many related surfaces which can be used for sieving type or micropatterning of microchannel by which a precise result can be generated and can be modified using microchannel network for experimental work after fabrication of the microchannel for different surfaces are as shown in (**Figure 10**). For fabrication in micropatterning it has some processes used in BioMEMS and carried for

Micropatterning in BioMEMS for Separation of Cells/Bioparticles

http://dx.doi.org/10.5772/intechopen.76060

83

• **Patterning process** in MEMS is the transfer of pattern into a material lithography is widly

(1) Lithography where some types of categories are available with its process as Photolithography, Electron beam lithography, Ion beam lithography, Ion track technology and X-ray

Depending on different modeling, analysis of microchannel and sieve type patterns the fabrication can be proceeded with reliable material which can withstand some parameters for a patterned chip and can be sued in different areas for sample analysis like separation of particle and detection of bacteria from the given sample like CTCs, DNA, Klebsiella bacteria like

The main task which can be carried for separation are the size and mass of the bacteria ranging between 0.3 and 10 μm and mass weight can vary from 1 to 10−12 Kg depending on the sample in biological terms precisely. Similarly for Klebsiella species one of the bacteria cells are *K. pneumoniae* whose particle size varies around 0.5–2.5 μm. However the mass of the

micropatterning a channel as,

(1) Physical (2) Chemical

lithography

(1) Wet etching (2) Dry etching

• **Deposition process** which is subdivided into,

used process which are framed as,

• **Etching process** are subdivided into,

*E. coli*, *K. pneumoiea* and other types.

**Figure 10.** Different shape for microchannel (grooves).

**Figure 9.** (a) Separation by a DLD in an array of micro posts with streamlines shown with G is spacing between the gaps in structure [28] (b) and (c) Structure and rectangular shape have and x and y distance of 4.3 and 2 μm showing main channel and separation channel.

For the particle movement depending on the volumetric flow rate was measured in COMSOL multiphysics 5.2a software by the Navier-stokes equation in compressible fluid flow [29].

$$\left\{ \left( \rho \left( \frac{\partial \boldsymbol{u}}{\partial t} \right) + \boldsymbol{u} \cdot \nabla \boldsymbol{u} \right) \right\} \\ = \left\{ -\nabla p \right\} + \left\{ \nabla \cdot \left( \mu \{ \nabla \boldsymbol{u} + (\nabla \boldsymbol{u})^{\Gamma} \} \right) - \frac{2}{3} \left\mu (\nabla \cdot \boldsymbol{u}) \Gamma \right\} + F \tag{7} \tag{7}$$

There is a unique term that corresponds to the inertial forces, viscous forces, pressure forces and external forces which are applied to the fluid flow as Eq. (7) plays a vital role for the flow and to predict the movement for the particle according to the volumetric flow through the channel. For the different velocity magnitude at various streamlines for the particle in microchannel-1 is calculated on the basis of Eq. (7) precisely in COMSOL multiphysics 5.2a. By solving equation for specific conditions include inlets, outlets and walls predictions for the velocity and pressure in geometry can be observed and using sieves or grooves in a microchannel can be simulated.

However instead of rectangle type shape in microchannel there are many related surfaces which can be used for sieving type or micropatterning of microchannel by which a precise result can be generated and can be modified using microchannel network for experimental work after fabrication of the microchannel for different surfaces are as shown in (**Figure 10**). For fabrication in micropatterning it has some processes used in BioMEMS and carried for micropatterning a channel as,

	- (1) Physical
	- (2) Chemical
	- (1) Wet etching
	- (2) Dry etching

For the particle movement depending on the volumetric flow rate was measured in COMSOL multiphysics 5.2a software by the Navier-stokes equation in compressible fluid flow [29].

**Figure 9.** (a) Separation by a DLD in an array of micro posts with streamlines shown with G is spacing between the gaps in structure [28] (b) and (c) Structure and rectangular shape have and x and y distance of 4.3 and 2 μm showing main

There is a unique term that corresponds to the inertial forces, viscous forces, pressure forces and external forces which are applied to the fluid flow as Eq. (7) plays a vital role for the flow and to predict the movement for the particle according to the volumetric flow through the channel. For the different velocity magnitude at various streamlines for the particle in microchannel-1 is calculated on the basis of Eq. (7) precisely in COMSOL multiphysics 5.2a. By solving equation for specific conditions include inlets, outlets and walls predictions for the velocity and pressure in geometry can be observed and using sieves or grooves in a microchannel can be simulated.

<sup>3</sup> *<sup>μ</sup>*(∇⋅ *<sup>u</sup>*)*I*} <sup>+</sup> *<sup>F</sup>* (7)

<sup>∂</sup>*<sup>t</sup>* ) <sup>+</sup> *<sup>u</sup>* ⋅∇*u*)} <sup>=</sup> {−∇*p*} <sup>+</sup> {∇⋅ (*μ*(∇*<sup>u</sup>* <sup>+</sup> (∇*u*)*T*)) <sup>−</sup> \_\_<sup>2</sup>

{(*ρ*(

channel and separation channel.

82 MEMS Sensors - Design and Application

\_\_\_ ∂*u*

Depending on different modeling, analysis of microchannel and sieve type patterns the fabrication can be proceeded with reliable material which can withstand some parameters for a patterned chip and can be sued in different areas for sample analysis like separation of particle and detection of bacteria from the given sample like CTCs, DNA, Klebsiella bacteria like *E. coli*, *K. pneumoiea* and other types.

The main task which can be carried for separation are the size and mass of the bacteria ranging between 0.3 and 10 μm and mass weight can vary from 1 to 10−12 Kg depending on the sample in biological terms precisely. Similarly for Klebsiella species one of the bacteria cells are *K. pneumoniae* whose particle size varies around 0.5–2.5 μm. However the mass of the

**Figure 10.** Different shape for microchannel (grooves).

bacteria particle of *K. pneumoniae* changes with the size of the particle and remains in a range of 10−12 to 10<sup>8</sup> Kg. Depending on the volumetric flow rates in microfluidic system for a hydrodynamic filtration method the flow rates for the separation of *K. pneumoniae* bacteria from the sample can be precisely separated. Similarly the flow rates depending on the fluid viscosity and density can test at different flow rates in microliters (μl) numerous times for the inlets. According to model designed in (**Figure 7**) can be tested with two or multiple types of particles differing in size and shapes for the separation however it is possible for experimentation and simulation in software like COMSOL Multiphysics 5.2a, Intellisuite and other related tools. Whereas the clogging problem in the channel can be reduced using this structure which is a major issue for separation in micropatterned channels. Thus can achieve higher throughput sorting when a separation occurs at every intersections and robust against the problem of clogging in microchannel.

Sieve type microchannel network is designed with main channel and a separation channel where the cells with sample are continuously introduced through an inlet-1 and the other inlet-2(buffer) through which the sample is injected without cells to precede the sample in the flow to decrease the fluctuations in flow when moving through the chip. Overall outputs (Four outputs) through which bacteria particles can be counted at it rates and pressure by which separation can be easily identified. As per the experimental simulations shown in **Figures 11** and **12** (Graphs) it give a probable results by which the larger particles of different mass are been detected through output-4 and the smaller particles of same mass and size are relatively sorted through the other outputs depending of the fluid flow rates which are mostly detected from output-3 and output-2. However Smaller particles will reach the ceiling (upper region) of the primary channel But the larger particles cannot because of the hydrodynamic effect. Owing to the change in frequency of particles they gets shifted toward right direction according to the fluid rate and buffer effect by which paticles are individually identified

**Figure 12.** (a) Outputs for microchannel vs. Number of bioparticles seprated(%)(m/s) plot when water is passed through grooves at 50 μl/s for different angles, (b) Similarly, Outputs for microchannel vs. Number of bioparticles separated(%)

Micropatterning in BioMEMS for Separation of Cells/Bioparticles

http://dx.doi.org/10.5772/intechopen.76060

85

(m/s) plot when blood is passed through grooves at 3000 μl/s for different angles.

**Figure 11.** Shown in (a), (b), (c) and (d) Sieve type-shaped Microchannel at different angles with water solution at 50 μl/s of fluid flow rate in water. Similarly tested at different flow rate for different angles with measureable flowrates and simulated with blood sample properties also with the software COMSOL Multiphysics 5.2a.

bacteria particle of *K. pneumoniae* changes with the size of the particle and remains in a range

dynamic filtration method the flow rates for the separation of *K. pneumoniae* bacteria from the sample can be precisely separated. Similarly the flow rates depending on the fluid viscosity and density can test at different flow rates in microliters (μl) numerous times for the inlets. According to model designed in (**Figure 7**) can be tested with two or multiple types of particles differing in size and shapes for the separation however it is possible for experimentation and simulation in software like COMSOL Multiphysics 5.2a, Intellisuite and other related tools. Whereas the clogging problem in the channel can be reduced using this structure which is a major issue for separation in micropatterned channels. Thus can achieve higher throughput sorting when a separation occurs at every intersections and robust against the problem of

**Figure 11.** Shown in (a), (b), (c) and (d) Sieve type-shaped Microchannel at different angles with water solution at 50 μl/s of fluid flow rate in water. Similarly tested at different flow rate for different angles with measureable flowrates and

simulated with blood sample properties also with the software COMSOL Multiphysics 5.2a.

Kg. Depending on the volumetric flow rates in microfluidic system for a hydro-

of 10−12 to 10<sup>8</sup>

clogging in microchannel.

84 MEMS Sensors - Design and Application

**Figure 12.** (a) Outputs for microchannel vs. Number of bioparticles seprated(%)(m/s) plot when water is passed through grooves at 50 μl/s for different angles, (b) Similarly, Outputs for microchannel vs. Number of bioparticles separated(%) (m/s) plot when blood is passed through grooves at 3000 μl/s for different angles.

Sieve type microchannel network is designed with main channel and a separation channel where the cells with sample are continuously introduced through an inlet-1 and the other inlet-2(buffer) through which the sample is injected without cells to precede the sample in the flow to decrease the fluctuations in flow when moving through the chip. Overall outputs (Four outputs) through which bacteria particles can be counted at it rates and pressure by which separation can be easily identified. As per the experimental simulations shown in **Figures 11** and **12** (Graphs) it give a probable results by which the larger particles of different mass are been detected through output-4 and the smaller particles of same mass and size are relatively sorted through the other outputs depending of the fluid flow rates which are mostly detected from output-3 and output-2. However Smaller particles will reach the ceiling (upper region) of the primary channel But the larger particles cannot because of the hydrodynamic effect. Owing to the change in frequency of particles they gets shifted toward right direction according to the fluid rate and buffer effect by which paticles are individually identified through outputs. Similarly different shapes of particles like non-spherical or rod-type shape can be utilized and detected through microchannel network for sorting. By this system of sieve network it achieves a high throughput sorting while separation occurred at every intersection and is robust against the issue of clogging in microchannel network [6].

expected high throughput and clogging problem are the facts which has to be properly experimented for higher purpose of biological testings, their conditioning and patterning related fabrication techniques for developement with some characteristics and precise separation of cells should be one of the top priorities. Thus sieve-typed microchannel network can be a precise separation chip network which is efficient for hydrodynamic cell in microfluidic device of size and mass based separation. Effective for mucosal vaccine delivery systems, while flow can be related for immune protection against *K. pneumoniae* infection and suitable for group vaccination programs resulting in considerable health as well as economic benefits. Therefore to contribute to the different successful collaborations at this stage where the stability and the robustness of the microfluidic viability should be taken into care to steadily contribute to successful collaborations between different biomedical, clinicians, biologists, and other the

Micropatterning in BioMEMS for Separation of Cells/Bioparticles

http://dx.doi.org/10.5772/intechopen.76060

87

The authors would greatly acknowledge the support from National Institute of Technology Nagaland, Chumukedima, Dimapur, India and MEMs Design Centre from SRM university,

[1] Korsmeyer T, Zeng J, Greiner K. Design tools for BioMEMS. In: Proceedings of the IEEE International Conference on Design Automation; 7-11 July 2004. San Diego: IEEE; 2005.

[2] Arora A, Simone G, Salieb-Beugelaar GB, Tae Kim J, Manz A. Latest development in micro

[3] Gervais L, de Rooij N, Delamarche E. Microfluidic chips for point-of-care immunodiagnos-

[4] Tran NT, Aved I, Pallandre A, Taverna M. Recent innovations in protein separation by

microfluidic association.

**Acknowledgements**

**Author details**

**References**

Chennai, Tamil Nadu, India for their assistance.

Rajagopal Kumar and Fenil Chetankumar Panwala\*

Print ISSN: 0738-100X. pp. 866-870

tics. Advanced Materials. 2011;**23**:H151-H176

\*Address all correspondence to: fenilpanwala68@gmail.com

National Institute of Technology Nagaland Chumukedima, Nagaland, India

total analysis systems. Analytical Chemistry. 2010;**82**:4830-4847

electrophoretic methods : An update. Electrophoresis. 2010;**31**:147-173

Micro device having sieve-shaped micropatterned channel has been designed and simulated for a distinct slanted angles at 90, 15, 25 and 35° through which separation of mass and size-based particles from a sample was carried for *K. pneumoiae* beads (by using its properties). The model for the Sieve type microchannel has been done based on the equation for critical diameter, Navier-stokes equations analysis and accordingly depending on the mass and size of the particle it was separated through the main and separation channels of micropatterned chip of sieve type model. The fluid flow simulation was tested with blood sample and distilled water properties in simulation at different angles of channels by which a bigger particle as well as smaller particles were separately identified via outputs for the precise separation (**Figures 11** and **12**). The main channel and the separation channel were crossing at right angle and also the particles with the size of 3 and 8 μm (aspect ratio = 0.3) were separated through outputs at various flow rates in μl/s for blood and water mixed with properties of *K. pneumoniae* beads by micro channel network as the size of the *K. pneumoniae* varies from 0.5 to 2.5 μm shown in **Figure 11**.

We examined the model of separation at different input flow rates concerning about 13, 20, 25, 50, 66, 80 μl/s with water and 133, 666, 800, 1000, 3000, 5000 μl/s with blood by which the separation behavior of the particles using COMSOL Multiphysics 5.2a were simulated and calculation is done. Similarly, at various angles of the channels the samples through input were simulated for the quick and precise performance for the sorting of bacteria at different fluid flow rates mentioned shown in **Figure 12**.

Finally a discussion can be made for the *K. pneumoniae* particles that it can be examined with different size of the spherical or non-spherical shape cells for separation which has been a big issue in hospitals and routine lifestyle. Since infections *K. pneumoniae* are air borne type which is controlled by mucosal vaccination through pulmonary route and nasal can be an assured approach in order to resemble natural infection. Other than traditional vaccines new vaccines like subunit vaccines are safer but they have less immune response [30]. Therefore to enlarge their immunogenicity, dynamic and delivery systems and safe adjuvant are necessary to be developed. Thus by using micropatterning system the sorting of particle from samples can be easily invented [30]. Furthermore this microchannel network can be carried for different purposes for biological or industrial work and even for the separation of rod-type particles from the *K*. *pneumoniae* by improving separation efficiency and change or modification in design for the better cause.
