DB Profile

Education:

Ph.D. Indian Institute of Technology Kanpur, 2009

M.Tech. Indian Institute of Technology Kanpur, 2001

B.Tech. Calcutta University, Kolkata, 1998

B.Sc. Calcutta University, Kolkata, 1995

Research Interests:

· Colloid and Interfacial Phenomena

· Computational Fluid Dynamics

· Micro and Nano Fluidics

· Complex Flow and Fluids

· Clean Energy - Fuel and Solar Cells

Brief Overview of Research:

Stability and dynamics of thin (<100 nm) viscoelastic films are have been studied extensively in recent times because of their importance in various products and processes such as coatings, adhesives, microfluidic devices and membranes. They also appear as the lining of mammalian lungs, as the tear film of the cornea and in the contact region of the cell-cell or cell-substrate adhesion. Recent studies on thin films have shown a richer variety of instability and dewetting pathways that are of potential use in mesoscale patterning of polymers for optoelectronic, micro-electromechanical systems, and sensor applications. Stability of polymer films is essential in various conventional nanolithography techniques like electron beam lithography. Experiments involving the instabilities of thin films on patterned substrate are found to be extremely useful in generating large area patte! rns and its ‘positive’ or ‘negative’ replication. Polymer films also serve as simple hydrodynamic models for the adhesion of biological membranes.

Based on continuum hydrodynamic models for the thin films we study the behavior of these systems under the influnce of various forces. We employ the constitutive relations for the simple viscoelastic models to describe the materials. The instability in these systems is engendered by: (i) weak van der Waals forces or (ii) externally applied electric field force. With the help of linear stability analysis and nonlinear simulations, we explore many interesting aspects of the instabilities, which can be useful in the study of the deformations of nano-membranes (e.g. cell membrane), fabrication of self-organized meso-patterns and microfluidic devices.

As a part of our future research we wish to explore the roles of the microstructural properties on the behavior of these films. It is now well understood that the finer behaviors of these systems cannot be described through all macroscopic properties and to predict the behavior of these systems with higher precision, presently, we are studying these tiny systems from the multi-scale physics point of view. In parallel with theoretical modeling we are also in the process of setting up of a state of the art experimental facility to explore newer behaviors of these interesting systems.

We are also planning to study the effect of combined solar and fuel cells to improve the energy efficiency. It is most commonly known from the biological systems such as trees that they employ both solar and elctro-chemical energies combinedly to serve their purpose on a daily basis. Based on similar principals we are planning to build prototypes that can locally fulfill the energy needs. This perticular research is dedicated to the large demand of power in our country and the available chemical/solar energy at our disposal..

Overall we are exploring the instabilities that are inherent in the soft materials and finding out the possible applications employing these systems.