The area of Micro Nano Bio-Fluidics (MNBF) occupies a unique and prominent position in fundamental and applied research due to its coverage of the significant challenges being faced by mankind on energy, healthcare, and water. Our group primarily aims at focusing on cutting-edge research in MNBF and developing disruptive technologies by exploiting the material and energy transport through micro and nanoscale physics.
Our research spans the areas of Interfacial Microfluidics, Lab on Chip Technology, and Nanofluidics. Our interests lie in the fundamental understanding of the dynamics of fluid streams, interfaces, droplets, particles, and cells and energy transport at the micro/nanoscale. We are equally committed to utilizing the fundamental principles and techniques for the development of Lab on Chip technology for applications related to healthcare, energy, and water.
Seminar Title: Study of some soft matter systems using optical tweezers
Speaker: Rahul Vaippully
Optical tweezers is a very useful tool in physics, chemistry and biology. Although translational motion of trapped particles have been extensively studied, rotations are also being studied more recently. Of the rotations, in-plane or yaw motion has been developed over the last couple of decades. In this presentation, we explore yaw motion first and then move on to explore the first out-of-plane rotation which we call pitch motion in the nomenclature of the airlines.
We discuss our new method to generate yaw rotations with low ellipticity beams. Then, we use the yaw rotation to study adhesively of surfaces. We move on to detect pitch motion at high resolution and explore cell biological applications. Lastly, we explore strategies for calibration of optical tweezers inside the cell.
Seminar Topic: Open surface passive droplet manipulation
Speaker: Imdad Chowdhury
Passive droplet manipulation on open surfaces such as mixing, transport, and splitting has a broad range of applications, including condensation, electronic chip cooling, Lab-On-a-Chip (LOC) systems, and Point-Of-Care (POC) diagnostics. We have performed the numerical modeling of a few passive droplet manipulation techniques such as a) wettability patterning, b) texture gradient, and c) shape gradient of surfaces. We have focused on the wettability patterning and demonstrated a standalone power-free technique for transporting and splitting a droplet on an open surface using continuous wettability-gradients. A Y-shaped wettability-gradient track – laid on a superhydrophobic background – is used to investigate the dynamics of the splitting process. A 3D phase-field Cahn-Hilliard model for interfaces and Navier-Stokes equations for transport are employed and solved numerically using the finite element method (FEM). Numerical results are used to decipher the motion and splitting of the droplet at the Y-junction using the principle of energy conservation. The droplet splitting ratio (ratio of the sizes of daughter droplets) can be controlled by manipulating the widths of the Y-branches. The physics of the droplet transport, flow pattern inside the droplet, and the splitting mechanisms have been explained through detailed numerical studies and scaling analysis. We also studied the effect of wettability confinement on droplet transport. The study provides the required theoretical underpinnings to achieve autonomous transport and splitting of droplets on open surfaces, which has clear potential for applications in surface fluidic devices.
Title: 2D Membrane for Renewable Energy
Speaker: DR. Prahalad K. Barman
The blue energy (salinity gradient energy) identified as a promising non-intermittent renewable energy source. However, this membrane-based technology is facing major limitation for large-scale viability, primarily due to the poor membrane performance. The atomically thin 2D nano porous material with high surface charge density resolving the bottle neck and leading to a new class of membrane material for the salinity gradient energy.
Although the 2D nano porous membrane are showing extremely high performance in terms of energy generation through single pore, but the fabrication and technical challenge (like ion concentration polarization) making the nano porous membrane a non-viable solution. On the other hand, the meso and macro porous structures in 2D membrane are showing improved energy generation capacity. The laser assisted(femtosecond and ultrafast laser) technique making the fabrication of these pores is quick, low complex and hence making the membrane technology viable. In this talk, the details fabrication of these 2D membranes along with creation of macro pores in these membranes for blue energy generation will be discussed.
Seminar Topic: Molecular and supramolecular structure design for applications in Biomedical arena.
Speaker: Prof. Muraleedharan K. M
Dept. of Chemistry, IITM.
Abstract: Design of organic systems with pre-defined properties requires proper control at electronic-, conformational- or supramolecular levels. As part of our interest in this area, we are working on different types of compounds, which include both rigid three-dimensional frameworks as well as relatively flexible ones. Electronic control of redox stability in di hydroquinolines to identify new anticancer leads, folding preferences & controlled conformational transitions in synthetic peptides, modular design of drug delivery systems, and design of chemical probes for selective detection & quantification of gaso transmitters are some areas we are focusing at the moment. This presentation is intended to share the latest results with MNBF team so that areas of overlapping interest can be identified for collaborative research.
Particle migration under combined acoustic relocation and acoustophoretic force
Speaker: Amal Nath
PhD Scholar, Fluid Systems Laboratory
Bulk transport of fluid streams is observed when a co-flow of heterogeneous fluids is subjected to a standing bulk acoustic wave inside a microchannel. For most applications like particle sorting or cell washing, this bulk transport (‘acoustic fluid relocation‘) is prevented by ensuring that the co-flowing fluid streams have a negligible difference in density or compressibility. Here we demonstrate the behavior of dilute suspensions under acoustic relocation, by flowing a suspension of relatively lower acoustic impedance through the channel center flanked by side streams of high acoustic impedance. Under acoustic actuation, the low-impedance suspension stream gets transported (or relocated) to the sides. The particles may remain within the original suspending stream at the sides or enter the central stream and their dynamics is governed by the combined effect of relocation-induced drag and acoustic primary radiation force. Depending on the final configuration of the suspended particles, we characterize the different regimes in terms of the relevant timescales of advection, relocation and acoustophoretic migration. The operational parameters are non-dimensionalized and a general phase diagram is developed which provides some guidelines in developing relocation-based cell sorters and medium exchange devices. Numerical model predicting the complete/partial migration or non-migration of particles from the suspension to the relocated side stream is developed, in agreement with the experimental observations. Using the combined technique, we also experimentally demonstrate the medium exchange and size-based sorting of biological cells, which shows the potential application of the study in biochemical assays
Computational modelling of red blood cell mechanics
Speaker: SAINATH. H.
PhD Scholar, Micro and Nanoscale Transport Laboratory.
Hematological diseases affect millions of people annually. They include genetic disorders like hereditary spherocytosis, G6PD deficiency, and conditions related to HIV, sickle cell disease, in addition to blood cell cancers. Explicit modeling of blood has enormous importance in studying different cell sorting techniques, phenomena such as aggregation, hemostasis and hemolysis. Fundamental understanding of the intricate dynamics showcased by the cells would help us in disease detection and even provide vital information regarding the pathophysiology of the disease. Recently, there has been a tremendous interest in identifying biomarkers for cell-based diseases. Furthermore, microfluidic platforms and miniaturized lab-on-a-chip devices have made a considerable impact on point-of-care blood analysis, leading to effective diagnosis. Here, we focus on the numerical modeling of red blood cells (RBCs) in health and disease. A three dimensional, high fidelity in-silico RBC model capable of capturing hemodynamics has been developed. Dissipative particle dynamics ( DPD) and the theories of statistical mechanics are implemented to analyze the cell behaviour and morphology in microcirculation. After the completion of the rigorous model validation process, an in-depth comparison of cell mechanics in different pathological states are examined.