Mems-unit 5.doc

Regulations: BANNARI AMMAN INSTITUTE OF TECHNOLOGY (An Autonomous Institution Affiliated to Anna University) SATHYAMANGALAM – 638 401 Question Bank Department :Electronics and Instrumentation Engineering Branch & Semester : M.E-EIE & 02 Subject Code & Title : 14IE54 - Micro Electro Mechanical Systems Faculty Name

: Mrs. R. Rameswari

PART – A

Q. No.

1.

2.

3.

4.

5.

Question

The mobility of charge carriers in polymers is A) Less than silicon B)

More than silicon

C)

Equal to silicon

D)

Twice the silicon

The physical characteristics of a polymer material depends on A)

Molecular weight

B)

Material used

C)

Chain arrangement

D)

Molecular size

PMMA is A)

Poly methyl methacrylate

B)

Permanent Multipurpose Module

C)

Poly methanol methacrylate

D)

Poly methanol ethylacrylate

Synthetic polymers are derived from A)

Petroleum products

B)

Carbon material

C)

Plastic material

D)

Crystal

__________ can be remelted and reshaped repeatedly A)

Thermalplasts

B)

Thermalsets

Marks Thinking Skill (Blooms Taxono my) R

U

R

U

U

6.

7.

8.

9.

10.

11.

12.

13.

C)

Synthetic polymer

D)

Natural polymer

__________ have permanent shape after being melted once A)

Thermalplasts

B)

thermalsets

C)

Synthetic polymer

D)

Natural polymer

Polymer exhibits __________ behavior A)

Visco elastic

B)

Visco optic

C)

Opto elastic

D)

optoresistive

Polymeric materials are susceptible to time dependent deformation under constant stress called as A) Viscoelastic creep B)

Elastic deformation

C)

Strain

D)

Piezoelastic effect

Polyimide is widely used in microelectronics industry as A)

Insulating material

B)

Conducting material

C)

Semiconducting material

D)

Sacrificial layer

Cured polyimide films exhibit intrinsic stress on the order of A)

4x106 Pa

B)

6x106 Pa

C)

4x1012 Pa

D)

6x1012 Pa

____________ can serve as thick sacrificial layer for surface micromachining A)

SU-8

B)

LCP

C)

Polyimide

D)

Silicon

LCP is better than PMMA in A)

Stability & low moisture absorption

B)

High moisture

C)

Low power

D)

High density

PDMS is A)

An elastomer material

B)

Elastic material

C)

Plastic

U

R

U

R

R

R

R

U

D) 14.

15.

16.

17.

18.

19.

20.

21.

Metal

_____________ is a thermalset polymer and it is plastic material deposited using CVD A) Parylene B)

SU-8

C)

LCP

D)

Polyimide

___________ is a trademarked material by Asashi glass company of Japan A)

Cytop

B)

Teflon

C)

PMMA

D)

Parylene

_________provide excellent chemical inertness, thermal stability and nonflammability A) Fluorocarbon B)

LCP

C)

PDMS

D)

PMMA

Biodegradable polymers are A)

Thermalplasts

B)

Thermalsets

C)

Synthetic polymers

D)

Natural polymers

Piezoelectric polymers are A)

Electroactive polymers

B)

Biodegradable polymers

C)

Fluoropolymers

D)

Elastic polymers

In parylene pressure sensor, cost of development is reduced due to A)

Use of metal strain gauge and Surface micromachining

B)

Surface micromachining

C)

Use of metal strain gauge

D)

Bulk micromachining with silicon

Polymer MEMS flow sensor uses A)

NiCr on LCP cantilever

B)

NiCr on metal cantilever

C)

NiCr on silicon cantilever

D)

AlCr on LCP cantilever

Micro-optical systems presently have application in A)

Spectrometry

B)

Scanning and printing

C)

Large Space Inspection

R

R

An

U

U

An

R

U

D) 22.

23.

24.

25.

Heart surgery

____________can be used to create fiber optical alignment fixture systems A)

Bulk micromachining of silicon

B)

Surface micromachining of silicon

C)

Anisotropic etching

D)

Isotropic etching

Micro-mirrors are not used in

U

A)

Food processing

B)

Digital Light Projection systems

C)

Optical Switching

D)

Scanning

Variable-focus micro-lens using

R

A)

an ‘expandable’ polymer membrane

B)

Metal cantilever

C)

Silicon beam

D)

Plastic material

LCP is A)

Liquid Crystal Polymer

B)

Liquid Chemical Parylene

C)

Local Crystal Parylene

D)

Link Control Protocol

An

R

PART – B

1

What is meant by polymer?

2

Thinking Skill (Blooms Taxonom y) R

2

Why polymer is used in MEMS?

2

An

3

List any four applications of polymer MEMS

2

R

4

Classify polymers

2

U

5

What are the mechanical properties of polymers?

2

U

6

Name any four techniques for polymer processing

2

R

7

What is the barrier for using polymer in MEMS?

2

An

8

List the different polymers that are used in microfabrication

2

R

9

List the applications of polyimide

2

R

10

Write the chemical structure of SU-8

2

R

11

Identify the features of polyimide MEMS

2

An

12

Compare LCP and kapton

2

R

13

Identify the properties of liquid crystal polymer

2

U

14

Why PDMS is preferred in microfabrication?

2

U

15

What is PMMA? List any two applications of PMMA

2

U

16

Where the fluoropolymer is used?

2

U

17

List the merits of optical MEMS.

2

R

18

What is the purpose of micro lenses and mirror?

2

An

19

Name any four applications of optical MEMS

2

R

20

Compare polymer MEMS and optical MEMS

2

An

Q. No.

Question

PART – C

Marks

Compare and contrast the properties of three major classes of polymers List the different polymer used in MEMS and explain the mechanical and physical properties of polyimide and SU-8 polymer. What is meant by LCP? Discuss about the characteristics and applications of LCP in microfabrication. Draw the schematic diagram and explain the principle basic PDMS patterning process Write technical notes on (i) PMMA (ii) Parylene (iii) fluorocarbon Identify the different polymer used in MEMS and explain the mechanical and physical properties of parylene and LCP. Draw the schematic diagram of Parylene accelerometer an explain

12

Thinking Skill (Blooms Taxonomy) An

12

U

12

R

12

U

12

U

12

An

12

U

Identify the steps involved in fabrication of parylene accelerometer and explain with neat sketch Explain the working principle of Parylene surface micromachined pressure sensor with sketch Illustrate the major steps in the Parylene membrane fabrication process

12

U

12

U

12

U

Draw and explain the LCP piezoresistive flow sensor with its characteristic curve Explain the working principle of polymer based tactile sensor

12

U

12

U

12

U

14

Write technical notes on (i) Micro optical mirror (ii) Micro optical lenses Discuss any two applications of optical MEMS with neat sketch

12

U

15

Identify the different actuators for active optical MEMS and explain

12

U

Q. No. 1 2 3 4 5

6 7 8 9 10 11 12 13

Question

Marks

PART – D

1

Summarize the mechanical properties of polymers

6

Thinking Skill (Blooms Taxonomy) U

2

Draw and explain the actuators for active optical MEMS

6

U

3

Discuss about the properties of liquid crystal polymer

6

R

4

Explain the principle of operation of polymer MEMS pressure sensor.

6

U

5

Explain how the micro lenses are fabricated?

6

U

Q. No.

Question

Marks