TEQIP Workshop on

Indian Institute of Technology, Hyderabad


Organizing Committee

Dr. Ashok Kumar Pandey, Assistant Professor, Dept. of Mechanical and Aerospace Engg., IIT Hyderabad

Dr. Chandra Shekhar Sharma, Assistant Professor, Dept. of Chemical Engg., IIT Hyderabad

Dr. Prem Pal, Associate Professor, Dept. of Physics, IIT Hyderabad

TEQIP Workshop on MEMS and NEMS (Design and Fabrication)

December 15-19, 2014

Summary Report



Venue

Day 1

Lecture Hall (LH)-3,

Second Floor,

Indian Institute of Technology, Hyderabad,

ODF Estate, Yeddumailaram-502205

Day 2-5

Lecture Hall (LH)-2,

First Floor,

Indian Institute of Technology, Hyderabad,

ODF Estate, Yeddumailaram-502205

For Experimental Hands-on session (Day 2, 3, 5)

Research Labs

IIT Hyderabad Permanent Campus,

Kandi, Sangareddy-502285



Schedule

Day 1 (December 15, Monday)

8:30-9:30 Registration LH-3

9:30-10:00 Inauguration LH-3

10:00-11:00

Keynote Lecture

Electromechanical Spinning (EMS): A

New Nanomanufacturing Option

Prof. Marc Madou,

University of California,

Irvine

LH-3

11:00-11:30 High Tea

11:30-12:30 Open Session with Participants

Prof. Marc Madou,

University of California,

Irvine

LH-3

12:30-14:00 Lunch Hostel Mess

14:00-15:30

Tutorial 1

Brief Overview of Micro-fabrication

Processes

Dr. Prem Pal, IITH LH-3

15:30-15:45 Tea Break

15:45-17:15 Tutorial 2

Silicon based MEMS/NEMS Dr. Prem Pal, IITH LH-3

Day 2 (December 16, Tuesday)

9:30-11:00

Tutorial 3

Polymer and Carbon based MEMS &

NEMS

Dr. Chandra S. Sharma,

IITH LH-2

11:00-11:15 Tea Break

11:15-12:45 Tutorial 4

Biomimetic Route for MEMS Design

Dr. Chandra Shekhar

Sharma, IITH LH-2


14:15-17:30 Experimental Hands on Session-1 Research

Labs

Day 3 (December 17, Wednesday)

9:30-11:00

Tutorial 5

Fundamentals of MEMS/NEMS: Design

Perspectives

Dr. Ashok K. Pandey,

IITH LH-2

11:00-11:15 Tea Break

11:15-12:45

Tutorial 6

Journey from Micro to Nano: Ultra-

Sensitive Biosensor

Dr. Siva R. K. Vanjari,

IITH LH-2


14:15-17:30 Experimental Hands on Session-2 Research

Labs



Day 4 (December 18, Thursday)

9:30-11:00

Tutorial 7

Micromachined Ultrasonics Transducers

- Generating waves with low power

Dr. Siva R. K. Vanjari,

IITH LH-2

11:00-11:15 Tea Break

11:15-12:45 Tutorial 8

3-D IC: Opportunities and challenges

Dr. Shiv Gobind Singh,

IITH LH-2


14:15-15:45 Tutorial 9

Modeling and Analysis of MEMS/NEMS


IITH LH-2

15:45-16:00 Tea Break

16:00-17:30

Tutorial 10

Modeling and Analysis of Graphene

based MEMS Structures


IITH LH-2

Day 5 (December 19, Friday)

9:30-12:30 Experimental Hands on Session -3 Research

Labs


14:15-15:45 Interactive Session and Participant’s Feedback LH-2

15:45-16:00 Concluding Remarks LH-2

16:00 High Tea



Short Description of Five Days Workshop

Indian Institute of Technology Hyderabad hosted the ‘5 Days TEQIP Workshop on MEMS and

NEMS (Design and Fabrication)’ from December 15th to 19th 2014. This workshop was second in

the series of workshops. The previous workshop was organized last year from December 16th to

20th 2013. The previous workshop has some unique simulation hands-on-session using Intellisuite

software apart from the theoretical details of design and fabrication of MEMS and NEMS.

The present workshop was aimed at giving a more practical study of MEMS and NEMS and their

application. Apart from the theoretical concepts, this workshop also included the experimental

hands-on-sessions where each participants underwent a 4 day training in various micro-nano labs

at IIT Hyderabad, where they learned various fabrication and characterization techniques. The

hands-on-sessions was aimed at designing of simple MEMS and NEMS structures, fabrication

using photoresists, transfer of patterns into polymer using soft lithography and wet etching to

develop the suspended structures and their characterization using laser vibrometer.



The workshop started with lighting of the lamp ceremony with the chief guest and key-note speaker

Prof. Marc Madou, Chancellor’s Professor, Department of Mechanical and Aerospace

Engineering, University of California at Irvine, lighting the lamp and inaugurating the workshop.

The opening remarks were given by Prof. N V Reddy, Dean (R&D), IIT Hyderabad.

The workshop commenced with Prof. Marc’s lecture on ‘Electromechanical Spinning (EMS): A

New Nanomanufacturing Option’. He talked about the Electromechanical spinning- a technology

which their group developed recently which is a key advancement in electrostatic fabrication of

functional nanofibres by lowering of the opening voltage by several order of magnitude and an

attendant increase in patterning control compared to FFES. The EMS technology uses a

superelastic polymer based carrier ink that can be utilized in conjunction with functional materials

to pattern a range of versatile nanofibers with desired properties.

He demonstrated various applications where they have successfully patterned the nanofibres across

a wide range of diameters ranging from a few micros to sub 20nm. After his talk, there was a

question and answer session and the participants were excited with his work and they asked

questions on various aspects of EMS from fabrication to applications.

The next session was aimed at one-to-one interaction with Prof. Marc. The participants some of

whom were faculty members at various colleges asked Prof. Marc’s suggestions on the

introduction of specific courses on nanoscience and nanotechnology. Talking about the essential

courses which are the backbone of MEMS and NEMS technology, he specifically stressed on the



implementation of courses on ‘Quantum Mechanics for Engineers’ and ‘Scaling Laws’ in the

existing curriculum. He suggested that with a strong fundamental on Quantum Mechanics and

Scaling Laws, students can contribute significantly in the MEMS and NEMS domain. He also

talked about the introduction of various design and simulation courses using software like

Intellisuite, Comsol etc. He also said that practical knowledge backed up with theoretical concepts

can lead to innovations in India, thus he stressed on the implementation of hands-on-sessions for

students. He said that Indian students should strive towards competing at the same level how their

international counterparts are doing. He said that the environment should be such that students do

the same things while staying in India what they intend to do by going to MIT and Howard.

Talking on another topic on the essential equipment for setting up a minimum MEMS center at

their own institutes, Prof. Marc suggested the installation of those equipment which allows us to

alter its specifications. He said that equipment particularly designed to serve only one specific

purpose is not desirable in today’s world. He said that innovations will happens when students

start playing with the machine and altering its specification to suit the need of their experiment.

He also stressed on building low-cost machines by themselves instead of outsourcing them. He

was of the opinion that faculty members should invest more on intelligent students and less on

equipment.



Talking on the graduate curriculum for MEMS and NEMS, Prof. Marc suggested the

implementation of many courses at various semesters. The faculty members from the participants

along with Prof. Marc and faculty members from IIT Hyderabad brainstormed on the need for

specific courses and came up with an optimum semester-wise curriculum for a graduate degree on

MEMS and NEMS. Some of the suggestions in the design of curriculum included courses on

design software, more courses and hands-on sessions on rapid prototyping, inclusion of more CAE

software courses, a specific course on ‘Scaling Laws’, introduction of 3D printing technique right

from first semester where the first half will be focused on Computer Aided Design (CAD) and the

later half will be focused on 3D printing. Other suggestions included linking of MEMS and NEMS

to manufacturing like linking of techniques like SEM, TEM FIB etc with courses. Prof. Marc also

suggested the brainstorming on advanced concepts like scaling laws on non-linear systems while

discussing basic concepts during the course.

The participants appreciated the initiative in form of TEQIP workshop because of which they could

work closely with IIT Hyderabad faculty and benefit from their expertise in both setting up of labs

and designing curriculum on MEMS and NEMS. The interactive session ended with a memento

to Prof. Marc.

The workshop resumed in the afternoon session with Technical Tutorial 1 by Dr. Prem Pal,

Associate Professor, Department of Physics, Indian institute of Technology Hyderabad. He taught

various concepts of Microfabrication along with the fundamentals of silicon based MEMS and

NEMS. He taught various types of micromachining like surface micromaching and bulk

micromaching. He also taught the concepts involved in the method of Deep Reactive Ion-based

Etching (DRIE) and wet bulk micromaching. He used various physical 3-Dimensional models to



explain critical concepts like undercutting, trench formation, exposing of different planes etc. to

make the participants understand the concept. He also talked about the various etchants used in

micro-fabrication and the problems associated with each of them focusing on the critical aspects

to be kept in mind while choosing an etchant. He talked about the fabrication process in details

including all the steps of wafer cleaning, spin coating, pre-baking, photolithography, post baking,

etching and other talking about the various intricacies to be kept in mind while doing the process.

He also talked briefly about advanced topics like corner compensation techniques, the wagon

wheel methods to determine the etch rate of many planes etc.

On Day 2 (16th December) the session started with Tutorial 2 by Dr. Chandra Shekhar Sharma,

Assistant Professor, Department of Chemical Engineering, Indian Institute of Technology

Hyderabad. He taught the concepts and the steps associated with soft lithography. He emphasized

the need for polymer and carbon based MEMS & NEMS as next generation manufacturing. In his

second tutorial, Dr. Sharma has interestingly elaborated the various concepts found in Nature to

design the MEMS, popularly known as Biomimitic. In Biomimitic and/or Bioinspiration approach

to MEMS design, he lucidly brought out the scientific observation in a number of Natural objects

and based on that discussed the novel design routes for MEMS.



The session resumed in the afternoon with the Day 1 (Workshop Day 2) of hands-on experimental

session. All the participants were divided in three groups of 18 people each. Each group visited

alternate labs on turn basis.

On 3rd day of the workshop, Dr. Ashok Kumar Pandey, Assistant Professor in the Department of

Mechanical and Aerospace Engineering at IIT Hyderabad talked about the design perspectives of

MEMS/NEMS. After emphasizing on various steps required for the commercialization of MEMS

devices, he focused on the performance characteristics of a resonant MEMS devices which is

captured by resonance frequency and quality factor. He mentioned during his talk that the

sensitivity of these devices can be increased by increasing the resonance frequency and reducing

the damping. Afterwards, he talked about frequency tuning by residual stress, geometric

nonlinearity, electrostatic softening. He also mentioned about pull-in effect which occurs under

the application of large dc biased voltage. To show the influence of damping on MEMS devices,

he also talked about intrinsic damping such as thermoelastic damping, etc., and extrinsic damping

like support loss, squeeze film damping. He mentioned that most of MEMS devices, operating

under the ambient condition, are influenced by squeeze film damping. After characterizing the

flow based on Knudsen number, he mentioned about macroscopic as well as microscopic

modeling. After discussing the fundamentals of electrostatic and mechanical phenomena, he

discussed few test cases to showcase application of these theories in the design of MEMS/NEMS

devices.



On the next day (4th day of workshop), he discussed about the importance of carbon nanotube

modeling. After presenting few applications of carbon nanotube in nanoelectronics, biomass

sensors, etc., he mentioned about the characterization of carbon nanotube based on chiral vectors.

He also mentioned that the carbon nanotube is classified into zig-zag, arm-chair, and chiral

configurations. He showed different configuration of carbon nanotube and graphene using

nanotube modeler. He also stressed that the mechanical and electrical properties are influenced by

the configuration of carbon nanotube. Subsequently, he stressed on the modeling of mechanical

properties based on molecular dynamic simulation, molecular mechanics approach, and continuum

based approach. Using molecular mechanics approach, he showed that by suitably computing the

bending stiffness, axial stretching, and torsional stiffness, one can replace carbon-carbon bond by

a beam element. Such beam element can be used to model graphene or carbon nanotube of different

configuration in continuum based finite element software, ANSYS/ABAQUS. Finally, he pointed

out that such semi-continuum approach to model carbon nanotube will be useful in modeling CNT

based devices.

In another tutorial by Dr. Siva Rama Krishna Vanjari, he started with historic journey from micro

to nano in the field of sensors. As a main application in MEMS, sensors and actuators play a key

role and his talk was aimed to bring the fundamental design and fabrication aspects for sensors.

He also discussed his latest results on carbon nanofibers based sensors.

Similar to past two days, afternoon sessions were demoted to lab hands on sessions.

On last day of the workshop, there were two tutorials in the morning. Dr. Siva Rama Krishna in

his second tutorial discussed energy harvesting using MEMS devices while Dr. Shiv Gobind Singh

touched upon an important aspects of 3-D integration on MEMS with CMOS platform.



Experimental Hands-on Session

Experimental hands on session were focused on three main activities:

a) Microfabrication on Silicon wafer (MEMS and Micro/Nano Systems Laboratory)

b) Nanofabrication of carbon fibers (Chemical Engineering Research Lab)

c) Electrical and mechanical characterization of MEMS devices (Sensors and Actuators Lab)

MEMS and Micro/Nano Systems laboratory.

Dr. Prem and his students divided the 18 students in groups of 6 and each group did fabricated

MEMS structures like differently shaped cantilever beams, diaphragms, trenches with various

opening shapes etc. using wet bulk micromaching. They did spin coating of photoresist on the spin

coater, pre-baked them in the oven, pattern transfer under UV rays, development, post bake and

then wet etching. The students then visualized the various released structures under microscope

and carried the sample with themselves. Dr. Prem and his students explained to the participant’s

different theoretical phenomenon of fabrication and visualized them under the microscope. He also

showed the undercut corners of arrays of cantilevers and explained to them how undercutting starts

at the convex corner and how the concave corner remains firmly defined in all etchants. He also

explained to them how devices can be fabricated using the basic techniques of micromachining.

Chemical Engineering Research Laboratory

Dr. Chandra Shekhar Sharma and his students guided the participants in the hands-on session on

two major areas first being soft lithography and the second being carbon-MEMS (C-MEMS).

In the C-MEMS fabrication laboratory, Dr. Chandra and his students supervised the participants

in understanding the various experimental steps in fabrication of Carbon MEMS structures and



then performing the experiments themselves getting well equipped with the sophisticated

instruments and techniques. They used Si{100} wafer and coated it with SU8 2015 polymer. It

was later developed using SU8 developer and isopropyl alcohol. Various equipment like maskless

lithography, spin coater, microscope and 3D profiler were demonstrated to the participants to make

them well aware of the techniques to handle these equipment.

In the presence of Dr. Chandra and his students, the participants performed the various steps like

Wafer cutting and its dehydration bake

Spin coating of SU-8 on silicon wafer at 3000 rpm to get 15 µm thick film

Soft baking to remove excess solvent at 95 0C for 3 min.

Drawing a mask in paint

Patterning the created drawing using Maskless lithography system (Intelligent Micro

Patterning)

Post Baking to enhance the crosslinking

Developing the pattern and rinsing with IPA

Taking 3D image of patterned sample using 3D Profiler.



Apart from these the participants were also demonstrated pyrolyzed C-MEMS structures and they

were each given one patterned sample to assist them in teaching the same at their respective

colleges.

The participants were exposed to other advanced characterization tools for surface morphology

(SEM, Microscope and Profiler), chemical composition analysis (Gas chromatography & UV

spectroscopy, FTIR), Mechanical properties (Nanoindenter) etc. Several characterization tolls like

Optical Microscope and 3D profile were operated during the hands on session to make the

participants well aware of other existing technologies available in labs at IIT Hyderabad.

In the soft-lithography laboratory Dr. Chandra and his students demonstrated the students how to

replicate the surface structures or patterns of desired materials of interest to PDMS (Poly dimethyl

siloxane) using Soft lithography technique. The materials of interests included Compact Disk

(CD), Digital Versatile Disk (DVD), SU-8 patterns on silicon wafer and Canna Indica flower petal

(using as a Master Templates). The participants were guided to perform various fabrication

techniques like

CD-DVD Pattern:

Preparation of PDMS:

PDMS: Sylgard 184 from Dow Corning (Part A: Pre polymer and Part B: Cross linker)

Clean the beaker and pour 20 ml of PDMS pre polymer Part A from bottle.

Add 10% of curing agent Part B i.e, 2ml of cross linker into the PDMS and stir it.

After stirring remove all bubbles from the solution, keep the solution into the vacuum

chamber.

Preparing Compact disk for Lithography:

Remove the aluminium foil layer from the CD using a cutter and a sticking tape carefully.

Make a border around the objective area using the sticking tape

Preparing PDMS film:

Pour the PDMS solution on the bounded objective area up to the brim.

Cure this into the hot oven at 80° Celsius for about 2 hours and after curing peel off the

PDMS mold from master template.



SU-8 patterns on silicon wafer and Canna

Indica flower petal replicas:

Take a glass petridish attach the flower

petal/SU-8 patterns to the glass dish using double

sided tape (one side will attached to the glass

petridish and other side will attach to material of

interest petal or SU-8 patterns).

Make a border around the master template with thick tape to avoid the lekages of polymer.

Add the polymer to the master template, cure it on hot oven at 80 Celsius for about 2 hours.

After curing peel off the PDMS mold from master template.

Observation:

CD-DVD: Like CD and DVD rainbow colors can be observed on PDMS replica due to

surface patterns. SU-8 patterns: Inverse patterns of SU-8 can be observed on PDMS with

naked eye, by keeping the PDMS replica at certain angle when it is exposed to normal

light.

Sensors and Actuators Laboratory

Dr. Ashok and his students demonstrated the working of various instruments like oscilloscope,

function generator, spectrum analyzer, vibrometer etc. The focus was to make the participants well

equipped with the instruments and techniques used for mechanical and electrical characterization

or micro-structures. The session was aimed at demonstrating methods to find the natural frequency,

damping, frequency response, time signal, FFT of various structures and input signals.

Dr. Ashok demonstrated the working of function generator which is used to generate the input

signal of various forms like sinusoidal waves, square waves, ramp etc. These generated time

signals are very rich in content as we can extract a lot of information from them. It gives us the

time history along with the transient and steady state signals. The function generator was used to

generate the desired function which was then fed as input to the oscilloscope of the FFT. The



limitation of the function generator is that we cannot apply DC voltage and to overcome this

limitation a DC-meter was used. Using the DC meter the participants were explained how they can

apply different DC voltages.

In practical use, the input from the function generator undergoes some losses due to losses in cable

wires or other factors. To quantitatively measure these losses, the function generator was

connected to oscilloscope which gave us the actual signal after the losses. The participants were

demonstrated the various functions of the oscilloscope which they can exploit to get a lot of

information.

Later, FFT was explained to the participants which is used to obtain the spectrum of all range of

frequency. Various functions of the FFT was explained to the participants and they actively got

engaged in discussing intricate details of the concepts.

The laser vibrometer was then explained to the participants. The sophisticated vibrometer at the

Sensors and Actuators laboratory combines the function generator, oscilloscope, FFT,

displacement decoder, velocity decoder and many other advanced features. Dr. Ashok and his



students demonstrated the working of the vibrometer to the participants by mounting a test device.

Various applications of topography measurement, in-plane motion measurement using the

stroboscopic phenomenon and the out-plane measurement were explained along with their theory.

The Polytec Scanning Vibrometer (PSV) software was used to analyze various micro structures

like single cantilever, arrays of cantilevers, diaphragms etc. Frequency response was obtained for

various structures and the effect of noise was also explained to the participants. Another vibrometer

to measure the frequency response of macro-objects was also demonstrated to the participants.

The workshop was ended on December 19 with feedback session. A summary of feedback is given

below which shows the successful execution of this workshop.

S.No. Question Response

Excellent Good Satisfactory Unsatisfactory

1(i) Registration Process 27 20

1(ii) General organization 21 26

2 What is your opinion on the

workshop website?

(i) Content 22 25

(ii) Layout and navigation 16 25 6

(iii) Regular updates 18 27 2

3 Tutorials:

(i) How would you rate the

tutorials?

28 19

(ii) How was your interaction with

the faculty during the tutorials at

IITH?

26 17 4

4 Hands on Session

(i) Did the Hands on training

session meet your requirements

/expectations?

47 (Yes)

(ii) Were the learning modules

during hands on session

interesting and informative?

47 (Yes)

(iii) How would you rate the hands-

on sessions overall?

26 21

5 What is your opinion on lab

facilities at IITH?

36 11

6 How did this workshop may be

useful in your present activity

(Ph.D./Research/Teaching/any

other job?

5 (Ph.D) 29(Research) 9(Teaching) 4(others)

7 Overall Rating for TEQIP

Workshop on MEMS & NEMS

at a scale of 1-5

29(4) 18(5)



Documents

TEQIP Workshop on