We are interested in continuum scale modeling of various physical systems responsive to different physical inputs such as mechanical forces, magnetic/electric fields, chemical concentration gradient, etc. A large number of engineering applications involve strong multiphysics coupling in their operations. Some of my potential interests on these applications are (i) active navigation of magneto-active robots inside human body, (ii) pH and ion sensitive hydrogels for biomedical and agricultural applications, (iii) composite liquid crystal layers for biomedical applications and display technology, etc. Besides multiphysics modeling, I am also interested in dynamics of curious toys like the Rattleback, Tippe top, etc. Key results from the previous research works are summarized below.
We are actively looking for Ph.D. and M.Tech. students to work with on the above mentioned (or related) fields. Write to me at dipayanm@iitk.ac.in or stop by my office if you want to join me as a Ph.D. or M.Tech. student.
1. Dissipative continuum modelling framework for permanently magnetizable, soft elastomers:
We propose a fully dissipative continuum modelling in both F–H and F–B variable spaces for hard (permanently magnetizable) and soft (having no remnant magnetization) magnetorheological elastomers (MREs). Full-field finite element (FE) computations are carried out to model shape morphing of uniformly and non-uniformly pre-magnetized hard MREs. Figure (a) shown different shape morphing of non-uniformly pre-magentized MREs under the same remotely-applied periodic magnetic field. Figure (b) shows extreme deformation of magneto-architectured materials where both magnetized and non-magnetic members are present. The first arrangement shows extreme negative swelling whereas the second arrangement shows positive swelling of the material. Read more details about the model here in JMPS and here in IJSS.
2. Numerical homogenization estimates for the effective response of soft and hard magnetic elastomers:
Fetching the effective magneto-mechanical response of the representative volume elements (RVEs) comprising soft elastomeric matrix and magneto-active particles as fillers becomes crucial for two reasons. Firstly, it helps understanding the microstructural interplay in the composites that gives rise to magnetostriction (magnetization-induced strain in the materials) and secondly, it aids macroscopic phenomenological models for the soft and hard MREs. We propose an augmented variational principle for the numerical estimate for effective magnetostrictions in the RVEs. This is followed by a microstructurally-guided effective continuum modelling of the MREs at the macroscale. Details of the modelling and computations can be found here in IJNLM and here in JMPS.
3. Li ingress kinetics in the solid electrolytes of all-solid-state Li-ion batteries:
We investigate the Li filled and unfilled crack propagation in solid electrolytes of symmetric Li/SE/Li cells. We propose a full-field continuum model for the solid electrolytes in terms of energetic and dissipation potentials. The governing equations for the bulk SE and the electrode/SE interfaces comes readily from the proposed variational principle. Our simulation results explain the reason behind observing partially-filled cracks in the Garnet-type LLZO electrolytes and completely dry cracks in the Argyrodyte-type LPS electrodes. A detailed account on this investigation can be found here in a recent publication in Small Structures.
4. Instabilities in liquid crystal bilayers
Liquid crystals (LCs) are elongated macromolecules that can order themselves in nematic, twisted, chiral, etc. configurations. This work investigates the bifurcation of LC bilayers and their bifurcated patterns under applied electric fields. We start from a full-field continuum modeling of bulk LC layers via using the Frank-Oseen energy function. Subsequently, we perform a Bloch-Floquet stability analysis of the LC bilayers system to find critical electric fields for the Fréedericksz transition. The images below shows the bifurcated configurations of a 1:1 LC bilayer having 5CB (top) and 7E (bottom) layers. A detailed account on the model can be found here in our JMPS paper.
5. Active catheter propagation in blood vessels
We propose a physics-based computational model for active catheter propagation in blood vessels. A catheter with a magneto-active tip can be navigated remotely through manipulating the externally applied magnetic field. We propose a reduced-order continuum model for magneto-active catheter propagation. We model the extending/retracting flexible catheter shaft as a geometrically-exact beam, whose contact with the vessel walls are modelled via imposing node-based KKT-type no-penetration constraint considering a smooth vessel wall. Work is ongoing in this project.