Welcome to STEP Lab


PhD Amrinder Nain

Our Lab Founder

Professor Nain obtained his undergraduate engineering degree in mechanical engineering from Manipal Institute of Technology, India. He received his graduate degrees (MS in chemical engineering and Ph.D. in mechanical engineering) from Carnegie Mellon University, USA, working with Professors Metin Sitti and Cristina Amon. Before graduate school, Amrinder Nain worked in the industry (Larsen and Toubro, India in eutectic welding reclamation and Silicon Valley Group Lithography Systems (ASML, USA) in precision design, CAD, and robotics).


During his graduate studies, Amrinder invented the non-electrospinning Spinneret based Tunable Engineered Parameters (STEP) fiber manufacturing platform for precise control on diameter and spatial deposition of polymer fibers (US Patents 9029149 and 9902932). Subsequently, Amrinder joined the Institute of Complex Engineered Systems (Carnegie Mellon University) as a post-doctoral fellow to understand cell-fiber interactions. Amrinder moved to the Mechanical Engineering Department, Virginia Tech as an assistant professor in 2009 to expand his work in mechanobiology and established the STEP lab.


STEP lab focuses on the quantitative investigation of cell-fiber interactions with the goal of understanding disease development and progression. Of particular interest is linking sensing of suspended fiber curvature with mechanotransduction using Nanonet Force Microscopy (NFM, US Patent 9753023) for measuring single and multi-cellular forces.


In his spare time, Amrinder enjoys reading, cooking, and trying his hand at abstract art.

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Current Members

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Sharan Sharma

Role of Substrate Topology in Spheroid Formation

As a graduate student at the Mechanical Engineering department at Virginia Tech, I will be pursuing my Ph.D. through active research at the STEP Lab. My past experience with research includes developing an intracranial pressure sensor at Indian Institute of Science, and studying the erosion of a selective catalytic reducing material used in the exhausts of thermal power plants. I hope to help improve healthcare with its effectiveness and outreach in the near future. In my free time, I like to sketch, play soccer or badminton, or listen to music.


Daniel Zhang

Viscoelastic Effects on Cyclic Cytoskeletal Loading

I am a graduate student in UG/G program provided by the Mechanical Engineering Department in Virginia Tech. I started my researches and studies in STEP lab from fall 2019 semester and will keep working in STEP Lab as a graduate student. My primary research area is mototic cell dynamics. With the help of nano-fiber networks produced in STEP Lab, I am able to quantitatively measure the chromosome plane dynamics (rotations/vibrations) formed at metaphase of HeLa cells. I also worked on the interactions between pollen shells and hMSC cells seeding on the nano-fiber networks.
I received my B.S. in Mechanical Engineering from Virginia Tech and will keep learning in Virginia tech for my Master Degree.
I would like to spend my free time on making music, playing pc games, and cooking.


Christian Hernandez

Membrane Dynamics in Curvature Gradients

Mechanical Engineer, graduated from the University of Puerto Rico – Mayaguez (UPRM). He has engaged primarily in design for manufacturing (DFM). Christian worked with the foundation of the Center for Advance Aerospace Technologies (CAVE). As part of CAVE he focused on teaching GD&T, DFM, CNC, milling, 3D printing (both FDM and SLS) and injection molding to students. His prototypes at CAVE resulted in successful components for design teams such as: SAE Formula, SAE Baja, Solar Boat team and Honeywell UAV. Before working at CAVE, he worked in collaborative NSF REU between Virginia Tech and Technische Unversität Darmstadt where he researched calibration methodologies for cameras in autonomous cars. On his free time he works as a manufacturing engineer on a startup company called Agrobeads which is based in MIT. He is also an avid cyclist and reader of mostly fantasy/scifi books.


Atharva Agashe

MOMP Activation in Fibrous Substrates

 am a first-year PhD student in Mechanical Engineering Department. I am currently working on apoptosis where I am trying to capture the outward forces exerted by cells and correlate them to key apoptotic events like MOMP and Caspase activation. I am also working with Christin on FRET Lamin sensor to measure the forces on nuclear invaginations.

I did my undergrad in aerospace engineering from the University of Washington in Seattle and then came to Virginia Tech to start my Ph.D. In my free time, I love to cook, bake and enjoy outdoor activities such s hiking.


Previous Members


Apratim Mukherjee

Changes in Cellular Protrusions with Metastatic Potential

I am a 5th year PhD student working in both the STEP lab and the MicroN BASE lab at Virginia Tech. My research primarily focuses on investigating how cancer cells use protrusions (“cell arms”) to sense suspended nanofibers. As part of this investigation, I have found that cancer cells use a coiling mechanism at the tips of their protrusion to wrap around the fiber axis (similar to plants coiling around vertical structures in a garden!). Interestingly, metastatic cancer cells appear to show more pronounced coiling compared to their non-metastatic counterparts. I am also currently investigating key proteins that might underpin this new behavior with a focus on BAR proteins such as IRSp53 that is well known to regulate membrane curvature.
Prior to joining Virginia Tech for my PhD, I received my B.S. in Mechanical Engineering with a minor in Economics from Lafayette College in 2014. After graduating from Lafayette, I worked at Citibank as a Corporate Banker in the global healthcare space.
In my free time, I love reading books, listening to true crime podcasts, and watching soccer matches.


Aniket Jana

Invagination Mechanics of Nuclei in Fibrous Substrates

I am a 5th year PhD candidate in the Department of Mechanical Engineering at Virginia Tech. My research interests primarily lie in studying the nuclear mechanics in suspended fibrous environments. In particular, I am interested in elucidating the role of fiber network geometry in regulating the 3D nuclear shape and single cell gene expression. In a recent study, I demonstrated how using crosshatch network geometries of varying inter-fiber spacing, the plasticity of the migratory phenotype can be regulated, with highly elongated cells having thicker nuclei, moving faster and persistently in very dense fiber networks. My current research focuses on the force transmission from cell-fiber adhesions to the nucleus, which leads to nuclear compression and translocation of various transcription factors like YAP/TAZ. Before joining Virginia Tech, I have received my Bachelors in Mechanical Engineering at the Indian Institute of Technology, Kharagpur in 2015. Outside research, I am a huge fan of epic fantasy fiction and mystery thriller novels.


Abinash Padhi

Contractile Forces in Stem Cell Differentiation

I am a PhD candidate in the Mechanical Engineering Department. My primary research interests lie in deciphering the role of forces in facilitating stem cell differentiation. To this effect, I worked on developing a nanofiber-based force model, termed as Nanonet Force Microscopy, that accounts for biological cues of cells to determine cellular forces. In the process, we identified a unique behavior of anisotropically stretched cells that extend 3D Force-exerting Perpendicular Lateral Protrusions, thereby contributing to tumor expansion. Currently, I am also working in collaboration on developing another fiber-based force sensor which incorporates Machine Learning and mechanics principles to estimate forces exerted by cells in crosshatch geometry. From our studies in cellular migration, we concluded that mitochondrial activity is not the primary energy source for migration; instead, glycolytic pathways contribute heavily to facilitate cellular migration. I hail from Odisha, India. I completed my Bachelors in Mechanical Engineering from National Institute of Technology, Tiruchirappalli, India in 2015. I am an avid food enthusiast and love my tryst with amateur home cooking in my leisure time.


Aldwin Pagulayan

CIL Interactions and Predictions of Outcomes

I am currently a first-year Master's student in Mechanical Engineering working in the STEP Lab. My research area focuses on the cellular dynamics involved in contact inhibition of locomotion (CIL). CIL is a phenomena where cells collide, inhibit protrusions, repolarize, then migrate in different directions. I am interested in determining the rules of CIL in various suspended nanofiber designs and in various cell types (fibroblasts, cancer cells, etc.), along with the molecular mechanisms involved. I received my B.S. in Mechanical Engineering with a minor in Biomedical Engineering from Virginia Tech. In my free time, I like to run and make music with my guitar.

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