Go to the top
Dr. Sid Pathak Research Group

Dr. Sid Pathak

ASSISTANT PROFESSOR OF CHEMICAL AND MATERIALS ENGINEERING

News



Manish Jain Presentation at TMS 2017

March, 2017

Mr. Manish Jain gave a presentation on the topic of "micro-mechanical testing of Mg/Nb multilayer nanocomposites for ultra high strength and ductility" at the TMS conference 2017 in San Diego, California.
Manish Jain
TMS


Young Leaders Professional Development Award from TMS 2017

March, 2017

Professor Pathak receives the Young Leaders Professional Development Award from The Minerals, Metals and Materials Society (TMS) at the 2017 annual meeting in San Diego. The award aims to enhance the professional development of young members of the TMS by involving them in the long-term planning of the TMS.
TMS 2017 Young Professional Award


Group Trip to Sana Cruz Island

March, 2017

Professor Pathak, Manish Jain, Souyma Varma, and Cayla Harvey visited Santa Cruz Island off the coast of Southern California after attending TMS 2017 in San Diego.
Santa Cruz Island 2017


Nevada Today News Article- MoonArk Project

February 3rd, 2017



TMS 2017 Student Travel Grant

December, 2016

Manish Jain has received the TMS student travel grant to attend the TMS 2017 Annual meeting and Exhibition. The grant is for $300. TMS will take place in San Diego, California on February 26 thru March 2.
Manish Jain
TMS


Prof Pathak awarded the 2017 TMS MPMD Young Leaders Professional Development Award

November, 2016

Prof Pathak is one of two recipients of the 2017 TMS MPMD (Materials Processing & Manufacturing Division) Young Leaders Professional Development Award. The TMS Young Leaders Professional Development Award was created to enhance the professional development of dynamic young people from TMS’s five technical divisions by helping them participate in Society activities, become better acquainted, make important contacts with TMS leaders, and network with prominent Society members.
Sid Pathak
Sid Pathak
Additionally, as a Young Leaders Professional Development Award recipient Prof Pathak receives the following:
  • TMS membership for the year of the award.
  • Sponsorship to attend the TMS Annual Meeting & Exhibition for the year of the award.
  • Complimentary registration to the TMS Annual Meeting & Exhibition.
  • Accommodations at a hotel within the TMS room block.
  • $500 travel allowance toward airfare and round-trip transportation from airport to hotel.
  • Tickets to conference social functions.
  • Admission to appropriate division luncheon and council meetings at the TMS Annual Meeting.
  • Admission to the Young Professionals Tutorial Luncheon.
  • Admission to technical and administrative committee meetings at the TMS Annual Meeting.
  • Invitation to attend the TMS board of directors meeting as an observer.



Invited seminar at Ohio State University

October, 2016

Professor Sid Pathak gave presentation on "Probing Nanoscale Damage Gradients in Irradiated Metals using Nano-mechanical Test Techniques" at Materials Science and Engineering colloquium, Ohio State University.
Sid Pathak
Sid Pathak


Carnegie Mellon’s MoonArk project

September, 2016

Research work on carbon nanotubes selected for the Carnegie Mellon’s MoonArk project. The work selected here is expected to travel to the Moon (!!) aboard a lunar lander. When the lunar mission is finished, it is intended that the MoonArk will remain on the Moon as an enduring time capsule depicting elements of Earth’s art, architecture, design, music, drama, ballet, poetry, sciences, humanities, and technologies. This work will also be incorporated into a duplicate MoonArk object, which is expected to be included in a Moon Arts exhibition in various cities. In addition, all or part of this work may be included on web sites and other electronic media and in exhibit catalogs, posters, displays, promotional materials and other similar materials in connection with the Moon Arts Project and related exhibitions.
Students involved: Ms. Cayla Harvey and Mr. Cordero Nuanez
Cayla Harvey
Cordero Nuanez
Carbon Nanotube Side View
Carbon Nanotube Top View


Mechanical Engineering (ME-UNR) Invited seminar

September, 2016

Professor Sid Pathak gave a seminar on Studying the Local Mechanical Response of Irradiated Metals using Nano-mechanical Test Techniques", at University of Nevada, Reno
Sid Pathak
UNR


Cayla Harvey- NSF EPSCoR UROP Scholarship

September, 2016

Ms. Cayla Harvey was awarded the Nevada National Science Foundation’s Experimental Program to Stimulate Competitive Research (NSF EPSCoR) 2016 Academic Year Undergraduate Research Opportunity Program (UROP) fellowship. As an award recipient, she receives $4,000 to support her research project from September 5, 2016 through May 31, 2017.

Cayla Harvey
Epscor Nevada


Cordero Nuanez- Berkley Presentation

August, 2016

Mr. Cordero Nuanez gave a presentation at the University of California, Berkley on August 4th as part of a symposium for the McNair Program. He presented on the Mechanical Response of Vertically Aligned Carbon Nanotubes Reinforced by Inter-tube Bridging to fellow scientists and professors at the symposium.
Cordero Nuanez
McNair


Soumya Varma- Differential Fee Graduate Research Assistantship

August, 2016


Ms. Soumya Varma was awarded the Differential Fee Graduate Research Assistantship from the Dean’s office for two semesters (Fall 2016 and Spring 2017). The assistantship was in the amount of $13,000 total including salary, tuition and fringe from the Dean’s Office, with another $13,000 total including salary, tuition and fringe in matching funds from the faculty advisor.
Soumya Varma
UNR


Manish Jain- Los Almos National Laboratory

Summer 2016

Mr. Manish Jain spent his 2016 summer (June-August 2016) at the Center for Integrated Nanotechnology (CINT) in Los Alamos National Laboratory (LANL). At CINT-LANL. Mr. Jain was involved in PVD synthesis of the Mg/Nb multilayer nanocomposites, as well as characterizing the deposited films using residual film stress measurement, nano-indentation, and XRD. Mr. Manish Jain’s trip was funded through the NAASIC 2016 Seed Funding.
Manish Jain
LANL


Cody Falconer- 2016 Summer Internship

Summer 2016

Mr. Cody Falconer did a ten-week internship at Lawrence Livermore National Laboratory working with the additive manufacturing group in the Materials Engineering division. He worked on determining the resolution of their projection -stereolithography printing system by developing his own test pieces and collecting resolution data. He also worked for a short period on creating acrylamide hydrogels for a heart model.

Cody Falconer
Lawrence Livermore National Laboratory


Cordero Nuanez- 2016 McNair Scholar

May, 2016

Mr. Cordero Nuanez was awarded the 2016 McNair Scholars Program assistantship. The McNair Program provides a 8 Week summer research program, a $3,500 Stipend, GRE preparation course and test fee waiver, Graduate school preparation, application assistance, application fee waivers, faculty mentoring, travel to academic conferences, and academic and personal support.
Cordero Nuanez
McNair


Manish Jain-OISS UNR International Student Award

May, 2016

Mr. Manish Jain was awarded International Graduate Student Award of $1000 in May 2016 from the Office of International Students and Scholars (OISS) at UNR. This award is given to international graduate students every spring based on their academic performance and research proposal.

Manish Jain
Manish Jain


NAASIC 2016 Seed Funding

May, 2016

Sid Pathak (PI) receives the NAASIC 2016 Seed Funding ($10k) for Interdisciplinary Research titled “Manufacturing interface dominated microstructures in bulk metal-metal composites for ultra-high strength and formability”
These funds were used for Mr. Manish Jain’s summer visit to Los Alamos National Laboratory.
Sid Pathak
NAASIC


Research


Nano-mechanics: quantitative measurement of material behavior at lower (micron to sub-micron to nanometer) length scales over a wide variety of material systems.
  • Mechanical behavior of irradiated materials for nuclear applications
  • Establishing processing-microstructure evolution linkages in polycrystalline metals
  • Manufacture of ultra-strong, ductile and thermally stable metal-metal and metal-ceramic composites using a bio-inspired nanolayered design
  • On biological materials my work focuses on more reliable assessment tools at the micro-scale for bone fragility conditions such as osteoporosis
Spherical Nanoindentation Stress-Strain Curves
Manufacturing ultra-strong, and ductile metal-ceramic nanolaminates multilayered composites
Mg-Nb Strength from In-Situ SEM Micro-Pillar Compression Testing
Open Cell Foams Indentation on VACNTs VACNT Micro-Pillar Compression
Irradiation on Au Nano-Foams

Spherical Nanoindentation Stress-Strain Curves

We have pioneered the development of novel data-analysis protocols for spherical nanoindentation which allow meaningful indentation stress-strain curves to be extracted from the raw datasets. See our review paper in Materials Science and Engineering: R for details.

Pathak S, Kalidindi SR. Spherical nanoindentation stress-strain curves. Materials Science and Engineering: R: Reports 2015;91:1-36

Applications


Indentation on anisotropic samples

Combining indentation measurements with the local lattice orientation(s) (measured using EBSD) to account for the effects of anisotropy at the indentation site in various anisotropic polycrystalline metal samples.
figure showing indentation results

Figure (a) Indentation yield in as-cast Fe-3%Si steel varies from one grain to another mainly due to the orientation differences between the grains, while Yind in deformed samples depends on both the orientation and the increased dislocation content at the indentation site. (b) and (c) show the measured load-displacement data and their corresponding indentation stress-strain responses respectively performed on near (111) grains in as-cast and 30% deformed Fe-3%Si steel.

S. Pathak and S. R. Kalidindi, Materials Science and Engineering: R: Reports, 2015, 91, 1-36.

Determining mechanical response of near grain boundary regions

figure showing mechanical response
Figure Using Yind to determine grain boundary character. The decrease in Yind close to the boundary on the side of grain D5 suggests a potential sink behavior for this boundary in 30% deformed Fe-3%Si steel. S. Pathak, J. Michler, K. Wasmer and S. R. Kalidindi, Journal of Materials Science, 2012, 47, 815-823.

Probing nanoscale damage gradients with spherical nanoindentation

figure showing nanoscale damage
Figure (a) Upon ion-irradiation, the metal surface is modified by a damaged layer, which causes a change in its mechanical response as compared to the bulk of the sample. (b) Map of the logarithmic strain component along the indentation direction (LE22) for a spherical indenter in the indentation zone (~2.4a, where a is the contact radius) close to the indentation yield. Both the contact radius a, and hence the volume probed by indentation, can be controlled with a proper choice of indenter radii. This approach is thus ideally suited for measuring any mechanical changes in the material surface layers, such as probing the (c) damage caused by He irradiation on a tungsten sample.
figure comparing indentation stress-strain responses
Figure. Comparing the indentation stress-strain responses between annealed (orange curve) and irradiated (black curve) W grains of near (001) orientation for three different indenter tip radii (a) 1 µm, (b) 10 µm and (c) 100 µm. (d) Illustration showing how changes in the indenter size (and the corresponding indentation zone) can be used to systematically probe different length scale effects in radiation damaged samples.
S. Pathak and S. R. Kalidindi, Materials Science and Engineering: R: Reports, 2015, 91, 1-36.

Mechanics and Materials Approach to Quantitative Assessment of Bone Quality

figure showing bone qualityUsing Raman spectroscopy and spherical nanoindentation to elucidate structure property correlations at the microscale in mouse femur bone. S. Pathak, J. Gregory Swadener, S. R. Kalidindi, H.-W. Courtland, K. J. Jepsen and H. M. Goldman, Journal of the Mechanical Behavior of Biomedical Materials, 2011, 4, 34-43. S. Pathak, S. J. Vachhani, K. J. Jepsen, H. M. Goldman and S. R. Kalidindi, Journal of the Mechanical Behavior of Biomedical Materials, 2012

Micro-to-nano mechanical testing strategies

Research in our group is focused on developing new approaches for nanomechanical test techniques. The mechanical testing can be performed both ex-situ as well as in-situ inside an SEM.

figure showing fabricated 3D test geometries for nano-mechanical testing
Figure. FIB fabricated 3D test geometries for nano-mechanical testing of (a) micro-compression cylinder, (b) microscale 3 point bend beam, (d) cantilever microbend beam.

This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is operated by Los Alamos National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract DE-AC52-06NA25396.

Applications

Manufacturing ultra-strong, and ductile metal-ceramic nanolaminates multilayered composites

Measuring strength using micro-compression testing Micro-pillars
Comparing the compressive response of Cu-TiN multilayers of 5 nm vs 50 nm layer thicknesses

Acknowledgment:
Dr. Nathan Mara, Center for Integrated Nanotechnologies, Los Alamos National Laboratory, NM

Measuring strength using in-situ SEM micro-pillar compression testing



figure showing indentation results

Figure FIB fabricated Mg-Nb 50nm-50nm micro-pillars with interfaces orientated normal, parallel and 45 degrees to compression axis.

This work explores the possibility of synthesizing a novel material system whose properties are dominated by a hitherto unstudied hexagonal close-packed (hcp) – body-centered cubic (bcc) interfaces. By refining the length scales to nanometer dimensions, and coupling orientations between the two phases, the final composite system is expected to have an enhanced strength as well as ductility, in spite of the inherent low ductility of the Mg phase. Such nano-Mg-X alloys are postulated to enable significant increases in its ductility from that of conventional hcp Mg and the nanostructure is expected to bring about an order of magnitude increase in strength, while retaining the lightweightness (high strength-to-weight ratio) of elemental Mg. We utilize a combination of indentation testing and in-situ SEM (scanning electron microscope) micro-pillar compression experiments to study the deformation.



Measuring ductility using micro-scale fracture toughness testing using a 3-point bend geometry
Comparing the fracture response of Al-TiN multilayers

Acknowledgment: Dr. Nathan Mara, Dr. William Mook. Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Sandia National Laboratory, NM


Open cell foams

Our techniques have also been successfully applied on softer open-cell foam materials such as vertically aligned carbon nanotube (VACNT) forests and metallic (Au) foams for measuring the mechanical performance and failure mechanisms under different loading (static vs. dynamic vs. cyclic), boundary (indentation vs. compression), thermal (from liquid nitrogen to 300 C), and irradiation conditions.
Indention movie
VACNT recovery under indentation. 100 nm/s displacement rate, shown at 30 times its original speed
Sudden instability under indentation in VACNT. Sample B, 100 nm/s displacement rate, shown at 25 times its original speed

Pathak, S., J.R. Raney, and C. Daraio, Effect of morphology on the strain recovery of vertically aligned carbon nanotube arrays: An in situ study. Carbon, 2013. 63: p. 303-316
Micro-pillar compression
The video illustrates the buckle formation of a VACNT micro-pillar compressed at a 100 nm/s displacement rate. The online video file, synchronized with its engineering stress-strain response, is shown at 35 times its original speed.

Pathak, S., N. Mohan, E. Decolvenaere, A. Needleman, M. Bedewy, A. J. Hart and J. R. Greer (2013). "Local Relative Density Modulates Failure and Strength in Vertically Aligned Carbon Nanotubes." ACS Nano 7(10): 8593-8604.
VACNT micro-pillar deformation at 1000 nm/s showing an almost 100% recovery

Pathak, S., E. J. Lim, P. Pour Shahid Saeed Abadi, S. Graham, B. A. Cola and J. R. Greer (2012). "Higher Recovery and Better Energy Dissipation at Faster Strain Rates in Carbon Nanotube Bundles: An in-Situ Study." ACS Nano 6(3): 2189-2197.
Effect of irradition on Au nano-forms
Microcompression of Ne ion irradiated gold nanofoam
Acknowledgment: Dr. Magdalena Serrano De Caro, Dr. Alfredo Caro. Los Alamos National Laboratory, NM
Radiation Induced Effects on the In-Situ Mechanical Properties Oof Nanoporous Gold Foams

Nanoporous metallic gold foams are characterized by a high surface-to-volume ratio and have become the focus of intensive research due to their attractive properties and potential innovative applications as actuators, in catalysis and in optical and biomedical applications. With pore size and ligaments in the nanometer range, gold nanofoams have the potential to become a new class of low density, high strength, and radiation resistant materials.

Radiation tolerance in gold nanofoams stem from the large amount of free surfaces in these structures that act as sinks providing opportunity for radiation-induced defects to annihilate through diffusion. In our current work we investigate the mechanical response of gold nanofoams before and after Ne-irradiation. Results from in-situ scanning electron microscopy (SEM) nanoindentation with a flat punch indenter are especially helpful in this respect, since they allow a one-to-one correlation between the applied indentation load and the deformation morphology of the gold nanofoam.


Lab Members

PI

Sid Pathak
Sid Pathak
Assistant Professor
Ph.D., Drexel University, 2009
LMR 466
Email: spathak@unr.edu

GRADUATE STUDENTS

Manish Jain
Manish Jain
Materials Science and Engineering Student
Email: jain.manish112@gmail.com
Curriculum Vitae

I grew up in India and received my Master’s degree in Materials Science and Engineering from Indian Institute of Technology Kanpur in 2015. I worked on the research topic “Porous alumina template by selective dissolution of Ni from sintered Al2O3-Ni composite” and published this research in a peer reviewed journal. I joined University of Nevada as a Graduate Research Assistant for my PhD in Materials Engineering in Spring 2016. My primary research interests include mechanical behavior of materials, in-situ microscopy, deformation characteristics of materials and powder metallurgy. Currently, I am working on the topic “Micro-Mechanical Testing of Mg-Nb Nano layered Composites for Ultra-High Strength and Formability” as a part of my PhD thesis in close collaboration of Los Alamos National Laboratory, New Mexico. With the intense need to reduce vehicle gas consumption and greenhouse emissions, lightweight Mg alloys are attractive replacements for the mild steels presently used in car bodies. Mg alloys have a high strength-to-weight ratio and low density, being 35% lighter than Al and 78% lighter than steel, and for every 10% decrease in vehicle weight fuel economy improves by an estimated 7%.

Apart from that I am an outdoor enthusiast like to play almost all sports, skiing, hiking and biking. Reno is a beautiful place with nice weather and I am pretty much involved in all these activities as well.
Souyma Varma


Soumya Varma
Materials Science and Engineering Student
Email: souyma@nevada.unr.edu

I have enjoyed science as far back as I can remember. Therefore, my interest in science and engineering drove me to pursue my undergraduate studies in Materials Science and Metallurgical Engineering at Maulana Azad National Institute of Technology, Bhopal, India and afterward filling in as a Research fellow at the Indian Institute of Technology-Kanpur India. It was my deep interest in the world of academia that drove me further to pursue a PhD.

I’m currently pursuing my PhD under the guidance of Professor Siddharth Pathak at the department of Materials Science and Engineering University of Nevada, Reno. My research interests include mechanical behaviour of materials, study of materials’ behaviour over lower length scales (micron to submicron levels), and spherical nano-indentation techniques.

Apart from my work I also enjoy reading books and inventing new recipes in my kitchen. I love dancing and would like to travel the whole world one day.

Undergraduate Students

Cordero Nuanez
Cordero Nuanez
Materials Science and Engineering Student
Email: corderonuanez@yahoo.com

I am Cordero Nuanez and I am a 28-year-old former sergeant in the United States Marine Corps. I have completed two tours of duty to Iraq and Afghanistan, but prior to leaving the USMC scientists came to one of my last mortar shoots to develop a new type of mortar. From this point on I wanted to become an engineer or a scientist. I was honorably discharged from the Marine’s in the summer and started at the University of Nevada, Reno that fall. I am currently enrolled at UNR and am seeking a bachelor’s degree in Materials Science and Engineering with a minor in Nanotechnology and am to graduate in the spring of 2017. I am currently working with Dr. Siddhartha Pathak on vertically aligned carbon nanotubes (VACNT) synthesized from Carbide Derived Carbon (CDC). The research project title is mechanical response of vertically aligned carbon nanotube (VACNT) brushes reinforced by intertube bridging. I have been analyzing all the data in the research project creating engineering stress vs strain graphs out of the data collected. Also, I have been creating multiple graphs and figures for all the data sets (i.e. 0.2% Yield, Moduli, Fracture Points, Summary File, etc.). My research interests are creating stronger lighter materials, Kevlar, how to improve Kevlar and anything that is dealing with taking or analyzing imagery of nanomaterials. I recently have been accepted to the McNair Scholars Post-bacculearate Program. I belong to the Wolfpack Veterans Club and AIChE professional society on campus.

I am very active when I am outside of school whether it be hiking, fishing, or going to the lake. I usually take part in the summer and winter basketball city league with my close friends. My wife and I like taking our animals to the park and for walks. If we were near a beach that had waves you wouldn’t be able to get me out of the water, since surfing is my all-time favorite thing to do. Otherwise I like watching movies, playing video games, and going to the gym.
Cayla Harvey


Cayla Harvey
Chemical Engineering Student
Email: caylaharvey@nevada.unr.edu

I am pursuing a bachelor’s degree in chemical engineering with an emphasis in materials science and am expected to graduate in Spring 2018. My interest in engineering led me to the program after I received a bachelor’s degree in business from the University of Nevada, Reno in Fall 2014. I started working with Dr. Pathak in January 2016 on vertically aligned carbon nanotubes (VACNT) reinforced by intertube bridging that was introduced by a Focused-Ion Beam (FIB). My current project is assisting in the analysis of stress and strain data from compression tests conducted on VACNT pillars of varying diameters. I received a scholarship from the Nevada National Science Foundation EPSCoR UROP program to continue this research.

Another one of my interests is everything culinary and food related. I enjoy cooking, experimenting in the kitchen, and researching food science. When I am not in the kitchen, I practice power yoga, hike, and spend time with my family.
Cody Falconer


Cody Falconer
Materials Science and Engineering Student
Email: codyfalconer@gmail.com

My name is Cody Falconer, and I am a senior pursuing my degree in material science and engineering. Outside of school I do not follow any one specific hobby. Instead I enjoy taking a break and doing any activity where I can find some fun. As an undergraduate I have had the chance to do some very exciting work. I have had the opportunity of being a discussion group leader where I taught a group of biology students more in depth details on some of the more general concepts they were learning in lecture. I have also had the incredible experience of being a summer intern working at Lawrence Livermore National Laboratory for two summers now. Currently I am working as an undergraduate research assistant with Dr. Pathak.

At Lawrence Livermore National Laboratory, I was working with a group doing projection micro-stereolithography. There I learned how to model test pieces using Autodesk Inventor software and how to adjust the projection parameters to optimize my printed pieces. I also collected data on the test pieces in order to create a limit on the resolution of one of the projection systems. Working with Dr. Pathak, I have analyzed data collected from nanoindentation on gold foam. The objective of this work was to measure how the mechanical properties of the gold foam, like the loading and unloading modulus, change once the gold foam has been treated with neon radiation.
Ethan Skemp


Ethan Skemp
Chemical and Computer Science Engineering Student
Email: ethanskemp@nevada.unr.edu

I was born and raised in California by my mother and grandparents. After graduating high school, I moved to Brazil for one year to learn Portuguese and delay adulthood for another year. After one semester at a junior college in California I moved to Reno where I started studying chemical engineering. As a chemical engineering student the areas that I find most interesting are process optimization and materials science. I started researching with Dr. Pathak in February of 2016 where my work has been focused on the utilization of mathematical software to facilitate data analysis. My efforts have been mostly focused in MatLab for video processing and data organization for vertically aligned carbon nanotubes, nano-lamellar metal-metal composites, and nano-lamellar metal-ceramic composites. Upon completion of my bachelor’s degree, I intend to enter industry and begin my career.

Publications

Mechanical Properties of Metallic MaterialsCeramic MaterialsNano-Mechanical Testing of Carbon Nanotube Arrays Materials for Biological ApplicationsBooks and Book Chapters

Mechanical Properties of Metallic Materials

# Title Journal Year
1 Investigations of orientation and length scale effects on micromechanical responses in polycrystalline Zirconium using spherical nanoindentation S Pathak, SR Kalidindi, N.A. Mara 2015
2 Probing nanoscale damage gradients with spherical nanoindentation Nanoscale
S Pathak, SR Kalidindi, Y Wang, R Doerner, N Mara
2015
3 On the Origins of Hardness of Cu-TiN Nanolayered Composites Scripta Materialia 109, pg 48–51
S. Pathak, N. Li, X. Maeder, R. G. Hoagland, J. K. Baldwin, J. Michler, A. Misra, J. Wang, N. A. Mara
2015
4 Spherical Nanoindentation Stress Strain Curves Materials Science and Engineering: R: Reports
Volume 91, pg 1–36
S Pathak, SR Kalidindi
http://dx.doi.org/10.1016/j.mser.2015.02.001
2015
5 Understanding pop-ins in spherical nanoindentation Applied Physics Letters 105, pg 161913
S Pathak, J Riesterer, SR Kalidindi, J Michler
2014
6 Caught in the Act – Grain-Switching and Quadrijunction formation in Annealed Aluminum Scripta Materialia 69, 37–40
S Pathak, RD Doherty, J Michler, K Wasmer
2013
7 Studying Grain Boundary Regions in Polycrystalline Materials Using Spherical Nano-Indentation and Orientation Imaging Microscopy
Nominated as finalist for the Journal of Materials Science Robert W. Cahn Best Paper Prize for 2012 (the “Cahn Prize”)
J. Materials Science Volume 47, Issue 2, pg 815-823
S Pathak, J Michler, K Wasmer and SR Kalidindi
2012
8 Size effects in Al nanopillars: single crystalline versus bicrystalline Acta Materialia 59(11), pg 4416-4424
A. Kunz , S Pathak, J. R. Greer
2011
9 Influence of lower current densities on the residual stress and structure of thick nickel electrodeposits Surface & Coatings Technology 205, pg 3651–3657
S Pathak, M Guinard, MGC Vernooij, B Cousin, Z Wang, J Michler, L Philippe
2011
10 Measurement of the Local Mechanical Properties in Polycrystalline Samples Using Spherical Nano-Indentation and Orientation Imaging Microscopy Acta Materialia v 57, n 10, pg 3020-3028
S Pathak, M Guinard, MGC Vernooij, B Cousin, Z Wang, J Michler, L Philippe
2009
11 Determination of an effective zero-point and extraction of indentation stress-strain curves without the Continuous Stiffness Measurement signal Scripta Materialia 60, pg 439-442
S Pathak, J Shaffer and SR Kalidindi
2009
12 Importance of Surface Preparation on the Nano-Indentation Stress-Strain Curves Measured in Metals Journal of Materials Research, Focus Issue on Nanoindentation 6v 24, n 3, pg 1142-1155
S Pathak, D Stojakovic, R Doherty, SR Kalidindi
2009
13 Determination of the effective zero-point and the extraction of spherical nanoindentation stressstrain curves Acta Materialia 56, pg 3533-3542
S R. Kalidindi, S Pathak
2008
14 Analyzing Indentation Stress-Strain Response of LaGaO3 Single Crystals using Spherical Indenters Journal of the European Ceramic Society 28, pg 2213-2220
S R. Kalidindi, S Pathak
2008
15 Analyzing Indentation Behavior of LaGaO3 Single Crystals using Sharp Indenters Journal of the European Ceramic Society 28, pg 2039–2047
S Pathak, SR Kalidindi, B Moser, C Klemenz, N Orlovskaya
2008



On Ceramic Materials

# Title Journal Year
16 Plasticity and fracture of sapphire at room temperature: Load-controlled microcompression of four different orientations Ceramics International 40 (1), pg 2083-2090
S Pathak, A Montagne, X Maeder, J Michler
2014
17 Mechanical behavior and electrical conductivity of La1-xCaxCoO3 (x = 0, 0.2, 0.4, 0.55) perovskites Journal of Power Sources 195, pg 3612
S Pathak, J Kuebler, EA Payzant, N Orlovskaya
2010
18 Mechanical behavior of La0.8Sr0.2Ga0.8Mg0.2O3 perovskites Ceramics International 35, pg 1235-1241
S Pathak, D Steinmetz, J Kuebler, EA Payzant, N Orlovskaya
2009
19 On Thermal and Vibrational Properties of LaGaO3 Single Crystals Acta Materialia 57, 10, pg 2984-2992
N Orlovskaya, M Lugovy, C Carpenter, S Pathak, D Steinmetz, E Lara-Curzio, C Klemenz, M Radovic
2009
20 Thermal and mechanical properties of LaCoO3 and La0.8Ca0.2CoO3 perovskites Journal of Power Sources v 182, n 1, pg 230-239
N Orlovskaya, M Lugovy, S Pathak, D Steinmetz, J Lloyd, L Fegely, M Radovic, A Payzant, E Lara-Curzio, L Allard, J Kuebler
2008
21 A TEM study on the doping behavior of calcium in LaCoO3 Microscopy and Microanalysis 12:728
M Chi, S Pathak, N Browning, N Orlovskaya
2006



Nano-Mechanical Testing of Carbon Nanotube Arrays

# Title Journal Year
22 Local Relative Density Modulates Failure and Strength in Vertically Aligned Carbon Nanotubes ACS Nano Vol 7, No 10, pg 8593-8604
S Pathak, N Mohan, E Decolvenaere, A Needleman, M Bedewy, AJ Hart, JR. Greer
http://dx.doi.org/10.1021/nn402710j
2013
23 Effect of morphology on the strain recovery of vertically aligned carbon nanotube arrays: an in situ study Carbon Vol 63, pg 303–316
S Pathak, J R Raney, C Daraio
DOI: 10.1016/j.carbon.2013.06.083
2013
24 Compressive response of vertically aligned carbon nanotube films gleaned from in situ flat-punch indentations Journal of Materials Research, focus issue DeNovo Carbon Nanomaterials 28 (7)
S Pathak, N Mohan, P PSS Abadi, S Graham, B A Cola, JR Greer
DOI: 10.1557/jmr.2012.366
2013
25 Higher Recovery and Better Energy Dissipation at Faster Strain Rates in Carbon Nanotube Bundles: an in-situ Study ACS Nano 6(3), pg 2189-97
S Pathak, N Mohan, P PSS Abadi, S Graham, B A Cola, JR Greer
DOI: 10.1557/jmr.2012.366
2012
26 Nanoshearingy Materials Today Vol 15, Issue 3, pg 127
SB Hutchens, E Decolvenaere, S Pathak, JR Greer
2012
27 Viscoelasticity and high buckling stress of dense carbon nanotube brushes Carbon Vol 47, pg 1969-76
S Pathak, ZG Cambaz, SR Kalidindi, JG Swadener, Y Gogotsi
2012



Materials for Biological Applications

# Title Journal Year
28 Lamellar level correlations between mechanical behavior and composition in mouse bone Submitted
S Vachhani, S Pathak, T Burr, K Jepsen, SR Kalidindi, H Goldman
2014
29 Assessment of lamellar level properties in mouse bone utilizing a novel spherical indentation data analysis method Journal of Mechanical Behavior of Biological Materials Vol 13, pg 102-17
S Vachhani, S Pathak, T Burr, K Jepsen, SR Kalidindi, H Goldman
2012
30 Measuring the dynamic mechanical response of hydrated mouse bone by nanoindentation Journal of Mechanical Behavior of Biological Materials Vol 4, pg 34-43
S Pathak, JG Swadener, SR Kalidindi, H-W Courtland, KJ Jepsen and HM Goldman
2011



Books and Book Chapters

# Chapter Title Book Year
31 - Indentation Stress-Strain Curves
Elsevier
In preparation
SR Kalidindi and S Pathak
2015
32 Mechanical Behavior of Carbon Nanotubes: from a Single Tube towards Complex Networks Structure and Multiscale Mechanics of Carbon Nanomaterials
Publisher: International Center for Mechanical Sciences (CISM), Udine, Italy
S Pathak
2015
33 Vertically Aligned Carbon Nanotubes, Collective Mechanical Behavior Encyclopedia of Nanotechnology (Springer)
Part 22, 2809-2818, DOI: 10.1007/978-90-481- 9751-4_387 (2nd edition in preparation)
S Pathak, S Hutchens
2012
34 - A Novel Data Analysis Procedure for Spherical Nanoindentation
Publisher: LAP Lambert Academic Publishing
S Pathak
2010



Teaching

Spring 2017

Biomaterials (MSE 457/657)

Phase Transformation and Kinetics (MSE 430/630)

Fall 2016

Materials Characterization (MSE 415/615)

Spring 2016

Phase Transformation and Kinetics (MSE 430/630)

Electron Microscopy. (MSE 710) Guest lecturer- ‘In-situ SEM mechanical testing’

Fundamentals of Nanotechnology. (MSE 495/695) Guest lecturer- ‘Nanomechanics’