memsQBfinal2016

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ANGEL

COLLEGE OF ENGINEERING

AND TECHNOLOGY

TIRUPUR 641 665

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

AS PER ANNA UNIVERSITY

REGULATION 2008

EE2033 MICRO ELECTRO MECHANICAL SYSTEMS

IV YEAR ELECTRICAL AND ELECTRONICS ENGINEERING

PREPARED BYAPPROVED BY

Mrs.C.K.Vijayalakshmi,AP/EEE

Dr.A.Pandian HOD/EEE



UNIT I- INTRODUCTION - MICRO ELECTRO MECHANICAL

SYSTEMS

PART - A

1. Define !n" #!$.

The statistically minimal energy needed to excite a covalently bonded electron to

become free charge carrier is called the band gap of the semiconductor material.

2. %&!' "( )(* +e!n ) in- ,i'* "($in#

The intentional introduction of impurities, called doping, would turn as intrinsic

material into an extrinsic semiconductor material. Impurities can be introduced into

number of ways, most notably through diffusion and ion implantation. They can also be incorporated into semiconductor lattice during the growth of material as well. This

process is called in-situ doping.

3. Define +e!n fee $!'&.

Mean free path is the average distance travelled by a moving particle (such as an

atom, a molecule, a photon) between successive impacts (collisions), which modify

its direction or energy or other particle properties.

/. Define ,&ee' e,i,'ii').

or a uniformly doped layer, the sheet resistivity is defined as!

The sheet resistivity is normally expressed as ohms"s#uare or $"%

or non-uniformly doped n-type layers, ie., if & is non-uniform!

The sheet resistivity of an emitter layer is typically measured with a four-point-probe.

. Define e!,'i +("**,.

'n elastic modulus, or modulus of elasticity, is the mathematical description of an

obect or substances tendency to be deformed elastically (i.e., non-permanently)



when a force is applied to it.

4. Define e!+.

' beam is structure member subected to lateral roads, that is, forces or moments having

their vectors perpendicular to the longitudinal axis.

5. %&!' "( )(* +e!n ) !n'iee*

' beam fixed at one end and free at another is conveniently referred to as fixed free

beam, commonly called a cantilever.

8. N!+e ,(+e (++(n) en(*n'ee" e!+ ,'*'*e, in MEMS.

+ouble - clamped suspension structures and single-clamped cantilevers.

6. %&!' !e '&e '&ee $e$!!'() ,'e$, e7*ie" '( !*!'e '&e *!'*e (f '&e

e!+.

Three preparatory steps!

. ind the moment of inertia with respect to the neutral axis

. ind the state of force and tor#ue along the length of beam

. Identify boundary conditions. Two boundary conditions are necessary to

deterministically find a solution.

10. %&) in'in,i ,'e,, i, i+$('!n' f( MEMS "eie,.

Intrinsic stress is important for M/M0 devices because it can cause deformation damages

in excessive cases, affect surface planarity, or change the stiffness of mechanical element.

11. N!+e '&e +!'ei! &!in# e( ,'e,,.

0ingle crystal bul1 silicon.

12. %&!' !e '&e ,'!'e#ie, f( +ini+iin# *n"e,i!e in'in,i en"in#

The strategies are!

. 2se materials that inherently have 3ero or very low intrinsic stress.

. or materials whose intrinsic stress depends on material processing parameter, fine

tune the stress by calibrating and controlling deposition conditions.

. 2se multiple layered structures to compensate stress-induced bending.

13. %&!' "( )(* +e!n ) 7*!i') f!'( 9:;

The sharpness of resonant pea1 is characteri3ed by a term called the #uality factor. The

sharper the resonance pea1, the higher the #uality factor.



1/. Define ,'e,, !n" e<$!in 'en,ie !n" (+$e,,ie ,'e,,.

0tress is defined as the external force applied per unit area. 4hen body is subected to

e#ual and opposite pulls, it elongates. The resistance offered to this elongation is tensile

stress. If body is subected to e#ual and opposite pushes, it contracts and the resistance

offered to this contraction is compressive stress.

1. Define ,'!in !n" e<$!in 'en,ie !n" (+$e,,ie ,'!in.

It is the ratio of change in dimension to the original dimension. The strain corresponding

to the tensile stress is called tensile strain and it is defined as the ratio of the increase in

the length to the original length. The strain corresponding to the compressive stress is

called as compressive strain. It is defined as the ratio of decrease in length to the original

length.

14. Define ,&e! ,'e,, !n" ,&e! ,'!in.

The two e#ual and opposite force act tangentially on any cross sectional plane of the

body tending to slide one part of the body over the other part. The stress induced is called

shear stress and the corresponding strain is 1nown as shear strain. 5r 0hear stress is the

resistance offered to the force applied. It is the ratio of shear force to shear area. The

corresponding strain is called as shear strain.

15. S'!'e H((=>, !? !n" e<$!in e!,'i i+i'.

It states that within elastic limit, the ratio of the stress and strain is a constant.

/lastic limit is a point on the stress strain diagram below which the body regains its

original shape when deformed, not necessarily obeying the hoo16s law.

18. %&!' )(* +e!n ) '&e+! ,'e,,e,

If the body is allowed to expand or contract freely, with the rise or fall of temperature no

stress is developed but if free expansion is prevented the stress developed is called

temperature or thermal stress and the corresponding strain is temperature strain.

Thermal stress 7 8. 9T. / @ Thermal strain 7 8. 9T

'7 the coefficient of thermal expansion of the material, 9T 7 change in temperature

16. %&!' i, en"in# +(+en'

The algebraic sum of the bending moment due to all the individual forces to the right or

to the right of the section.

20. %&!' !e '&e ')$e, (f '&e e!+



The different types of the beam are! a. ixed beam b. :antilever beam c. 0imply

supported beam. d. 5ver hanging beam e. :ontinuous beam.

PART -

. ;riefly explain about crystal planes and orientation in M/M0.

. In detail explain about the relation between tensile stress and strains also give the details

of mechanical properties of silicon.

. /xplain in detail about longitudinal strain under pure bending.

<. In brief explain about dynamic system, resonant fre#uency, and #uality factor.

=. In general discuss about intrinsic stress in M/M0.

>. +iscuss in detail about torsional deflections.

?. ' mechanical resonator has been demonstrated using 0i: thin film material. The length,

width and thic1ness of resonator are .@m, Anm, and ?=nm, respectively. Bnowing the

resonant fre#uency found experimentally was .A<CD3, and assuming a Eoung6s

modulus of ?AA CFa, find the density of the 0i: material used for resonator.

G. The intrinsic carrier concentration (ni) of silicon under room temperature is .=HAA

"cm. '

silicon piece is doped with phosphorous to a concentration of AG

cm-

.

The mobility of electrons and holes in the silicon are approximately =A cm"-s and

<GA cm"-s, respectively. ind the resistivity of the doped bul1 silicon.

J. Cive the relation between stress and strain in brief.

A. +iscuss in detail about photolithography process and also about :3ochrals1i (:K) method

for producing single crystal silicon.



UNIT II SENSORS AND ACTUATORS-I

PART B A

1. %&!' !e '&e +!( !"!n'!#e, (f ee'(,'!'i ,en,in# !n" !'*!'i(n

0implicity! The sensing and actuation principles are relatively easy to implement,

re#uiring only two conducting surfaces.

Low power! /lectrostatic actuation relies on differential voltage rather than current. The

method is generally considered energy efficient for low fre#uency applications. This is

especially true under static conditions, when no current is involved.

ast response! /lectrostatic sensing and actuation offers high dynamic response speed, as

the transition speed is governed by the charging and discharging time constants that are

typically small for good conductors.

2. Define ee'i! ,$in# (n,'!n'.

The spatial gradient of the electric force is defined as an electrical spring constant.

3. %&!' "( )(* +e!n ) $*-in ('!#e

't particular bias voltage, the two curves representing the mechanical restoring force and

the electrostatic force intercept at one point tangentially. 't the interception point, the

electrostatic and mechanical restoring forces balance each other. Moreover, themagnitude of the electric force constant e#uals the mechanical force constant. The

effective force constant of spring is 3ero. This is a special condition and should be dealt

with carefully in practice. The bias voltage that invo1es such a condition is called the pull

in voltage, or p.

/. %&!' "( )(* *n"e,'!n" !(*' (+ "ie "eie

Cenerally, one set of finger li1e electrode is fixed on chip while second set is suspended

and free to move in one or more axis. 0ince the interdigitated fingers are sharped li1e

tooth of combs, such configuration is commonly referred to as comb drive device.

. %&!' !e '&e '?( (nfi#*!'i(n, (f ee'(,'!'i '!n,"*e

Farallel plate and interdigitated comb drive.

4. %&!' i, '&e e!'ie "i,!"!n'!#e (f ee'(,'!'i !'*!'i(n

Digh voltage re#uired for static actuator operation is considered a drawbac1.



5. %&!' !e '&e '?( "iffeen' +(e+en', ) ?&i& $!!e $!'e !$!i'( i, +(e"

(i) Normal displacement. (ii) Farallel sliding displacement

8. %&i& f!'( "e'e+ine, '&e $e,,*e ,en,( ,en,i'ii')

The membrane thic1ness is a primary factor determining the pressure sensor sensitivity.

6. %&!' !e '&e !"!n'!#e, (f !$!i'ie $e,,*e ,en,(

Creater pressure sensitivity

Lower temperature sensitivity

Oeduced power consumption

10. %&i& ')$e (f $e,,*e ,en,( i, ,*i'e" f( $!!e !$!i'ie ,en,in#

Membrane based pressure sensor is ideally suited for parallel capacitive sensing.

11. %&!' i, '&e $ini$e (f !$!i'ie $e,,*e ,en,(

:apacitive pressure sensors are typically based upon a parallel plate arrangement

whereby one electrode is fixed and the other flexible. 's the flexible electrode deflects

under applied pressure, the gap between electrodes decreases and the capacitance

increases.

12. %&!' i, '&e +!in "!?!= !,,(i!'e" ?i'& !$!i'ie !$$(!& (f ,en,(

The main drawbac1s associated with the capacitive approach are the inherently nonlinear

output of the sensor and the complexity of electronics (compared with the resistive

bridge).

13. H(? n(nine!i') !n e !(i"e" in !$!i'ie $e,,*e ,en,(

The use of bossed diaphragms will mitigate this effect to some degree. 'nother

lineari3ing approach is to pattern the electrodes such that the sensing capacitance is

measured from a particular part of the diaphragm. Maximum deflection occurs at the

diaphragm center but this is also the location of maximum nonlinearity. ;y sensing the

capacitance at an annulus removed a short distance from the diaphragm center, non-

linearity is reduced but at the expense of sensitivity.

1/. H(? !n e '&e $!!,i'i !$!i'!ne !(i"e"

In order to reduce the effects of parasitic capacitance and achieve higher performance

devices, the pressure sensor should ideally be integrated with electronics. This is

achieved by combining a bul1-etched device with basic :M50 circuitry, but the more

common solution is to employ surface micromachining.



1. %&!' i, '&e ?i"e) $!'ie" +e'&(" f( "e$(,i'in# ,'*'*! !n" ,!ifii!

+!'ei!,

(:+) :hemical apour +eposition

14. %&!' !e '&e '?( ')$e, (f CVD

Low pressure chemical vapour deposition

Flasma enhanced chemical vapour deposition

15. %&!' !e '&e !i(*, !"!n'!#e, C(+-"ie ,'*'*e, e<&ii'

They have no sliding surfaces ma1ing them virtually showing no wear. The force of the

drives is independent of the position of the combs when one uses (the preferred) voltage

control.

18. %&!' !e '&e +!( $ef(+!ne (e'ie, in +i( +('( f!i!'i(n $(e,,

riction reduction and wear resistance.

16. H(? '&e ,!ifii! !)e, !e e+(e" in '&e $(e,, (f +i(-+('( f!i!'i(n

0acrificial layers are removed by immersing the wafer into D etch solutions.

20. H(? '( !(i" fi'i(n !n" ?e! $(e+ in +i(-f!i!'i(n $(e,,

The solution to the problem is to reduce the friction coefficient between rotor and hub by

ma1ing contact surfaces out of silicon nitride.



PART B

. /xplain in detail about the principle and wor1ing of electrostatic motor.

. +iscuss in brief about capacitance of parallel plates.

. 4hat do you understand by /#uilibrium position of /lectrostatic 'ctuator under bias*

<. 4hat is Full In effect of parallel plate actuators* /xplain in detail about it.

=. +iscuss in detail about parallel plate capacitive accelerometer.

>. 4hat do you understand by membrane parallel plate pressure sensor*

?. /xplain the fabrication process of condenser microphone.

G. /xplain in detail about the operation principle of scratch drive actuators.

J. 4hat are the applications of comb drive devices*

10.' parallel plate capacitor is suspended by two fixed guided cantilever beams, each with

length, width and thic1ness denoted l, w and t, respectively. The material is polysilicon

with Eoung6s modulus of A CFa.(l7<AA@m,w7A@m, and t7@m.) The gap Ho between

two plates is @m. The area of the plate is <AA@m by <AA@m. :alculate the amount of

vertical displacement when a voltage of A.< volts is applied. Oepeat the calculation of

displacement for the voltage of A. volts.



UNIT III SENSORS AND ACTUATORS-II

PART B A

1. Define '&e+! (n"*'i(n.

It is the transfer of heat through a solid media in the presence of a temperature gradient.

2. %&!' i, N!'*! '&e+! (ne'i(n

It is the transfer of heat from a surface into a stationary body of fluid. ' temperature

gradient in a fluid induces local flow movement through buoyancy. The movement of

fluid mass facilitates heat transfer.

3. %&!' "( )(* *n"e,'!n" ) '&e 'e+ f(e" '&e+! (ne'i(n

It is the transfer of heat to a body of moving fluid. The bul1 fluid movement provides

enhanced heat transfer compared with that of natural convection.

/. Define '&e 'e+ !"i!'i(n.

It represents the loss or gain of heat through electromagnetic radiation propagating in

vacuum or air.

. %&!' "( )(* +e!n ) ,$eifi &e!'

It is the amount of heat per unit mass re#uired to raise the temperature of an obect by one

degree :elsius or Belvin.4. Define TCE.

The volumetric thermal expansion coefficient is the ration between relative changes of

volume to the degree of temperature variation.

5. %&!' "( )(* *n"e,'!n" ) ine! e<$!n,i(n (effiien'

The linear expansion coefficient is the change of only one dimension of an obect due to

temperature variation.

8. %&!' i, '&e+! i+($& $ini$e

Two different materials, with different coefficients of thermal expansion, are oined

together in such a way, that a temperature change will cause the entire structure to deform

in a desired way.

6. %&!' !e '&e !"!n'!#e, (f '&e+! i+e'!i !'*!'i(n

Oelatively large range of movement can be achieved.



0mall actuator footprint for comparable displacement.

10. %&!' !e '&e "i,!"!n'!#e, (f '&e+! i+e'!i !'*!'i(n

Moderate to high power operation as current is used to generate ohmic heating.

Lower response speed as the time constant is governed by thermal heating and

dissipation.

11. %&!' !e '&e !"!n'!#e, (f Ee'(,'!'i !'*!'i(n

Low power operation at low fre#uencies.

Digh response speed.

12. %&!' !e '&e "i,!"!n'!#e, (f Ee'(,'!'i !'*!'i(n

Oelatively small range of motion.

Oe#uires large area and footprint in order to generate large force and

displacement.

13. %&!' !e '&e "iffeen' ?!), (f #ene!'in# &e!'

/lectromagnetic wave absorption

Oesistive heating

:onduction

:onvection

1/. %&!' i, +e!n' ) en' e!+ '&e+! !'*!'(,This structure will generate longer displacement than the thermal expansion of two arms

depending on the design angle.

1. %&!' i, +e!n' ) !'e! '&e+! !'*!'(,

Longer arm has higher electrical and thermal resistance hence is hotter hence expands

more causing lateral displacement. 4ider arm has lower electrical and thermal resistance,

hence is colder causing lateral displacement.

14. %&!' "( )(* +e!n ) '&e+((*$e

Two wires made of dissimilar materials oined at one point constitute a thermal couple. '

thermal couple is most commonly used to measure the temperature difference between

the oined sensing unction and a reference one. It is also used for generating electricity

from a temperature gradient between their two unctions.

15. %&!' i, ,ee!= (effiien'



The ratio between the developed open circuit voltage and the temperature difference is

the seebac1 coefficient.

18. %&!' i, '&e+! $ie

The output voltage from thermal couples will be increased when multiple thermal couples

are connected in an end to end fashion, with hot and cold unctions aligned. This

configuration is called a thermal pile.

16. %&!' i, '&e+! e,i,'(

' thermal resistor is an electrical resistor with appreciable temperature sensitivity.

20. %&!' i, '&e 'e+ '&e+i,'( efee" '(

The term thermistor is generally used to refer to semiconducting thermo-resistors.

' thermistor is a type of resistor whose resistance varies significantly with temperature,

more so than in standard resistors. The word is portmanteau of thermal and resistor.

Thermistors are widely used as inrush current limiters, temperature sensors, self-resetting

over current protectors, and self regulating heating elements.



PART B

. /xplain briefly about heat transfer processes associated with pot heating.

. 4ith neat diagram explain about thermal bimorph principle.

. +iscuss about bimetallic artificial cilia actuator in detail.

<. 4ith neat s1etch explain about bimetallic actuators for obect transport.

=. In detail explain about thermal couples.

>. +iscuss in detail about thermal resistors.

?. +iscuss in detail about accelerometer based on thermal transfer principle.

G. /xplain about fabrication process of surface micro-machined hot-wire anemometer.

J. In detail explain about thermal transfer shear stress sensor.

A. +iscuss about bimetallic structure for infrared sensing.



UNIT IV MICROMACHINING

PART - A

1. %&!' i, "iee'i effe' (f $ie(ee'ii')

It was observed that certain materials generate an electric charge when it

is under a mechanical stress. This is 1nown as dielectric effect of

pie3oelectricity.

2. %&!' i, ine,e effe' (f $ie(ee'ii')

The material would be able to produce a mechanical deformation when an

electric field is applied to it.

3. Define C*ie $(in'.

If a pie3oelectric element is heated to certain threshold temperature, the

crystal vibration may be so strong that domains become disordered and

the element becomes completely depolari3ed. This critical temperature is

called :urie point.

/. %&!' "( )(* +e!n ) ee'(+e&!ni! (*$in# (effiien'

/lectromechanical coupling coefficient 1 is a measure of how much

energy is transferred from electrical to mechanical or vice versa during the

actuation process.

. %&!' i, '&e +(,' f!+ii! !$$i!'i(n (f 7*!' ),'!The most familiar use of #uart3 crystal, a natural pie3oelectric material is

resonator in watches.

4. %&i& *ni7*e $($e') (f 7*!' en!e, i' '( e *,e" in 7*!'

),'! (,i!'(

The property of its oscillation fre#uency is #uite insensitive to

temperature changes ma1e it to be used in #uart3 crystal oscillator.

5. Define S$*''ein#.

0puttering is a form of Fhysical apor +eposition. It is used to deposit

thin metal films in the order of AA ' (' 7 A-A m) onto the substrate

surface. 0puttering process is carried out with plasmas under very low

pressure in high vacuum up to =xA-? torr and at room temperature. No

chemical reaction is involved in the deposition process.



8. %&!' i, '&e $i+!) !$$i!'i(n (f !(*,'i ?!e ,en,(

Frimary application of these sensors is to act li1e Pband filtersQ in mobile

telephones and base stations.

6. %&!' !e '&e ,e(n"!) !$$i!'i(n, (f !(*,'i ?!e ,en,(

0ensing of tor#ues and tire pressures.

0ensing biological and chemical substances.

0ensing vapors, humidity and temperature.

Monitor fluid flow in micro-fluidics.

10. %&!' !e '&e '?( (++(n ')$e, (f +i( $e,,*e ,en,(

• 0ensors using pie3o-resistors.

• 0ensors using capacitances.

11. %&!' !e '&e &!!'ei,'i, (f ,en,( *,in# $ie(-e,i,'(,

• 0mall in si3e R Linear I"5 relation R Temperature sensitive.

12. %&!' i, PVDF

The poly-vinylidenfluoride is a synthetic fluoropolymer with monomer

chains of (-:D-:-)n. It exhibits pie3oelectric, pyroelectric, and

ferroelectric properties, excellent stability to chemicals, mechanical

flexibility, and biocompatibility.

13. %&!' !e '&e !,,*+$'i(n, '( e +!"e f( !*!'in# *!'*e (f

en"in# (f ! (+$!' +("e

The induced stress and strain should be along axis or the

longitudinal axis of the :antilever. The beam maintains constant

curvature throughout the beam.

0hear effects are negligible.

;eam curvature due to intrinsic stress may be ignored .

Foisson6s ratio is isotropic for all films.

1/. %&!' "( )(* *n"e,'!n" ) PT

The lead 3irconatetitanate (FKT) system is widely used in polycrystalline

form with very high pie3oelectric coupling. The name FKT actually

represents a family of pie3oelectric materials. +epending on the formula

of preparation, FKT materials may have different forms and properties.



1. %&!' !e '&e "iffeen' +e'&(", (f $("*in# PT +!'ei!,

+ifferent methods of producing FKT materials are sputtering, laser

ablation, et molding and electrostatic spray deposition.

14. N!+e '&e +!'ei! *,e" !, (n"in# !#en' in $e$!in# PT

+!'ei!,

Lithium carbonate and bismuth oxide are used as bonding agent in

preparing FKT materials.

15. H(? !e nO +!'ei!, #(?n

Kn5 materials are grown using rf or dc sputtering, ion plating and

chemical vapor deposition.

18. %&!' !e '&e !$$i!'i(n, (f $ie(ee'i +!'ei!,

• :antilever pie3oelectric accelerometer membrane.

• Fie3oelectric accelerometer FKT.

• Fie3oelectric acoustic sensor FKT.

• Fie3oelectric microphone.

• Folymer pie3oelectric tactile sensor.

16. %&) nO i, *,e" in,'e!" (f PT

Kn5 is used instead of FKT, because, although the FKT material offers

greater pie3oelectric coefficient, it does so at the expense of greater

dielectric constant and hence larger capacitance.

20. H(? !e '&e ee'i! n(i,e !n" i+$e"!ne +i,+!'& effe', e"*e"

in $()+e $ie(ee'i '!'ie ,en,(

To reduce electrical noise and impedance mismatch effects, a two

dimensional matrix of high input impedance metal oxide semiconductor

field effect transistor amplifiers have been directly gate contact coupled to

the lower surface of a pie3oelectric F+ polymer film.



PART B

. +iscuss about mathematical description of pie3oelectric effects.

. ' =AA@m long cantilever type pie3oelectric actuator is made of two

layers, a Kn5 layer and a poly-silicon layer. The width, thic1ness and

material properties of these two layers are listed in table. ind the

amount of vertical displacement at the end of cantilever and the

transverse force at the end when the applied voltage is Av.

Kn5 Foly-silicon

4idth (@m) -A -A

Thic1ness (@m) , -

Eoung6s modulus ,>A ,>A

(CFa)

Fie3oelectric coefficient = N'(p:"N)

. In brief discuss about properties of representative FKT materials.

<. 4hat do you 1now about F+ and Kn5* /xplain in detail about it.

=. +iscuss about Kn5 pie3oelectric actuator.

>. 4ith neat s1etch explain about cantilever pie3oelectric accelerometer.

?. +iscuss about membrane pie3oelectric accelerometer with neat diagram.

G. +iscuss about FKT pie3oelectric acoustic sensor in detail.J. In detail explain about FKT pie3oelectric Microphone.

A. +iscuss about pie3oelectric flow rate sensor.

UNIT V - POLYMER AND OPTICAL MEMS



PART B A

1. Define +!#ne'i!'i(n.

' magnetic field may cause internal magnetic polari3ation of a piece of

magnetic material within the field. This phenomenon is called

magneti3ation.

2. Define +!#ne'i fie" in'en,i').

Magnetic field intensity (D) represents the driving magnetic influence

external to a magnetic material.

3. %&!' "( )(* +e!n ) +!#ne'i fie" "en,i')

Magnetic field density (;) represents the induced total magnetic field

inside a piece of magnetic material.

/. %&!' "( )(* *n"e,'!n" ) $!!+!#ne'i !n" "i!+!#ne'i +!'ei!

' magnetic material with a wea1 and positive magnetic susceptibility is

called paramagneticS one with a wea1 and negative magnetic

susceptibility is diamagnetic.

. %&!' i, ,!'*!'i(n +!#ne'i!'i(n

'fter the external induction field reaches a certain level magneti3ation

will reach a saturation point, called saturation magneti3ation.

4. Define e+!nene.

The fraction of the saturation magneti3ation which is retained after

Magnetic field intensity is removed is called remanence of the material.

5. %&!' !e '&e !,,e, (f fe(-+!#ne',

The two classes are hard magnets and soft magnets.

8. H(? !e '&e e<'en! +!#ne'i fie" !,,ifie"

The external magnetic field is classified as! uniform magnetic field and

non uniform magnetic field.

6. Define ,ee" !)e.

In many cases, the wafer is not conductive on its own. 2nder these

circumstances, the surface of a wafer is first coated with a thin film metal

layer for providing negative electric biasing. This thin film layer is called

the seed layer.



10. %&!' !e '&e !"!n'!#e, (f +!#ne'i !'*!'i(n

:apable of generating large angular displacement.

The possibility of using very strong magnetic as bias.

11. %&!' !e '&e "i,!"!n'!#e, (f +!#ne'i !'*!'i(n

Moderately complex processes.

+ifficulty to form on chip, high efficiency solenoids.

12. %&!' !e '&e +!( enefi', (f *,in# +i(-f*i" $!'f(+, '( e$!e

en& '($ &e+i,')

Oeduces dead volumes associated with a chemical assay system

with large scale chambers and connectors.

:an potentially reduce cost by saving the amount of expensive

chemicals and biological samples used for given analysis.

' microelectronic style bul1 fabrication will reduce cost of

sophisticated systems.

:an achieve high level of multiplicity and parallel operations to

increase the efficiency of chemical and biological discovery.

13. %&!' "( )(* *n"e,'!n" !(*' e,

:ells are basic functional units of life. The function of cell is determined

by the genetic se#uence it carries. ' basic human cell stores genetic codes,

reproduces such codes upon cell division, and manufactures protein

molecules based on such codes.

1/. %&!' !e '&e +(,' (++(n) e<$(i'e" i((#i! in"in# $('((,

;inding between antibody and antigens.

;inding between biotin and streptavidin molecules.

+N' complementary binding.

1. %&!' !e '&e ,ee! i+$('!n' f!'(, '( e (n,i"ee" ?&en

,ee'in# 'e&n((#ie, f( (n &i$ $*+$,



'chievable flow rate.

0implicity of fabrication.

:ost of fabrication.

0implicity of control.

Oobustness of the membrane.

;iocompatibility of membrane and channel materials.

14. %&!' "( )(* +e!n ) f(? e,i,'!ne (f ! &!nne

The ratio between the pressure difference and the volumetric flow rate is

called flow resistance of a channel.

15. %&!' i, ee'i "(*e !)e

The high capacitance charged region of ions at the interface of li#uid and

wall is referred to as the electric double layer.

18. %&!' !e '&e f!'(, '( e (n,i"ee" ?&en ,ee'in# ( "ee($in# !

+i(-+!&ine" !e

The reliability of valve operation.

The repeatability of valve operation.

The ability to withstand large pressure.

The simplicity of valve construction.

The simplicity of valve operation and control.

16. H(? !e '&e !e, !,,ifie" !("in# '( '&e +("e (f ($e!'i(n,

:yclic valves, 5ne-time valves and :onstant off valves.

20. H(? i, '&e !e ,'*'*e, !'e#(ie"

Dard-membrane valves.

0oft-membrane valves.

Flug valves.

Threshold valves.

PART -



. +escribe about design and fabrication of magnetic cell.

. /xplain about magnetic beam actuation in detail.

. +escribe about hybrid magnetic actuator with position holding.

<. +iscuss in detail about the method of pressure driven flow fluid movement.

=. +iscuss about electro-osmosis flow process in detail.

>. /xplain about integrated gas chromatography system with neat s1etch.

?. In detail explain about fabrication process of embedded micro channels.

G. In detail explain about fabrication process for a parylene channel.

J. +iscuss about pneumatic controlled F+M0 valve.

A. +iscuss about optical M/M0 and its applications.

memsQBfinal2016

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