Past Research Projects
Atomic Force Microscopy Facility
Bio-Mechanics of Cell
The research work is focused on the development of contact models and experimental methods of AFM force spectroscopy technique in soft material characterization, mainly polymer gels and live biological cells. Two of the most common issues in the analysis of nano-indentation data of soft materials has been addressed.
Firstly the correction to bottom substrate effect arising during thin sample studies and second, the contact model for simultaneous evaluation of nonspecific adhesion property along with elasticity. The developed contact model has applications in the characterization of soft materials showing adhesive elastic nature. The effectiveness of improvements made in the contact models are experimentally validated by testing transversely isotropic polymer gels of different stiffness and live MCF-7 adenocarcinoma cancer cells. Further, the developed correction factor for finite thickness correction is incorporated into a dynamic contact model for the study of viscoelastic nature of live cells. The model is applied in the study of micro-rheology of Human Measenchymal stem cells and HCT-116 Colorectal cancer cells. The main advantage of the proposed model is its analytical closed form expression, making it easy to use for AFM force spectroscopic data analysis.
Relevent Publications
Aditi Bhattacharya, Sumedha Saluja, Vishwanath Managuli V, Sandeep Agrawal S, Devanjan Dey, Bhavuk Garg, Mohammed Tahir Ansari, Sitikantha Roy, Sudip Sen, "Comparing migratory and mechanical properties of human bone marrow derived mesenchymal stem cells with colon cancer cells in vitro" Accepted in Journal of Gastrointestinal Cancer, 2020.
Viswanath Managuli, Sitikantha Roy, A Substrate Corrected Dynamic Rheological Characterization of Thin Sample and Biological Cells, Experimental Techniques, 2018.
V. Managuli and S. Roy, Asymptotical Correction to Bottom Substrate Effect Arising in AFM Indentation of Thin Samples and Adherent Cells using Conical Tips, Experimental Mechanics, 2017.
Viswanath Sivappa Managuli, Sitikantha Roy, Simultaneous Analysis of Elastic and Non-Specific Adhesive Properties of Thin Sample and Biological Cell Considering Bottom Substrate Effect, ASME Journal of Biomechanical Engineering, 2017.
Viswanath Sivappa Managuli, Sitikantha Roy, Influencing Factors in Atomic Force Microscopy Based Mechanical Characterization of Biological Cells, Experimental Techniques, 2017.
MEMS Modeling and Dynamical simulation, Energy harvesting
Presently reduced power requirement for small electronic components have been the main motivation for developing vibration based energy harvesting. The ultimate objective in this research field is to provide an easy, sustainable and efficient technology to power such small electronic devices from the unused vibrational energy available in the environment. A comprehensive, reliable mathematical technique is thus in high demand which can model a piezoelectric energy harvester, predict its coupled dynamics (structural and electromechanical) accurately. The present work focuses on developing a model for a slender, piezoelectric energy harvester based on Variational Asymptotic Method (VAM), a dimensional reduction methodology. VAM approximates the 3D electromechanical enthalpy as an asymptotic series to formulate an equivalent 1D electromechanical enthalpy functional to perform a systematic dimensional reduction. For validation purpose, we have picked up experimental results for a bi-morph PZT harvester, available in the literature. We have studied the extension-bending structural coupling along with the parameter dependency of the voltage, power output from the harvester and validated with the experiments.
Symbiotic Bio-mechanics II: Soft Robotic Assistive Glove
Soft robotics is a nascent research field where embedded intelligence in soft material deformation is coupled with precision control algorithm to achieve targeted task. Examples from biology are a great source to mimic in developing this technology. How octopus move, how our hand responds to brain electrical signals are all examples of man-machine interface, and inherently soft robotic mechanism. In conventional robotics, we deal with finite degrees of freedom to solve a multi-body mechanism to achieve desired goal/movement. On the contrary soft robotic manipulators are continuous system (theoretically infinite D.O.F), here the desired kinematical objective is achieved by utilizing the inherent softness of the manipulator. A typical example is like elephant trunk, or octopus tentacle-they are, soft in nature but still can achieve desired functionality by controlling the special distribution of stiffness through integrated actuation.
Material, which has embedded intelligence, actuation and sensing capability is the fundamental building block for soft robotics. In this aspect dielectric polymer has gained attention as artificial mussel like actuator. The project plans to use dielectric polymer like soft material, and intelligent actuation system to develop soft 1D manipulators through controllable rigidity concept.