TEQIP Workshop on
Transcript of TEQIP Workshop on
Indian Institute of Technology, Hyderabad
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
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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
12:45-14:15 Lunch Hostel Mess
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
12:30-14:00 Lunch Hostel Mess
14:15-17:30 Experimental Hands on Session-2 Research
Labs
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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
12:30-14:00 Lunch Hostel Mess
14:15-15:45 Tutorial 9
Modeling and Analysis of MEMS/NEMS
Dr. Ashok K. Pandey,
IITH LH-2
15:45-16:00 Tea Break
16:00-17:30
Tutorial 10
Modeling and Analysis of Graphene
based MEMS Structures
Dr. Ashok K. Pandey,
IITH LH-2
Day 5 (December 19, Friday)
9:30-12:30 Experimental Hands on Session -3 Research
Labs
12:45-14:15 Lunch Hostel Mess
14:15-15:45 Interactive Session and Participant’s Feedback LH-2
15:45-16:00 Concluding Remarks LH-2
16:00 High Tea
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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.
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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.
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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.
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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.
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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.
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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.
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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.
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad
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)
Indian Institute of Technology, Hyderabad
Indian Institute of Technology, Hyderabad