Micro Fluidics & Nano Patterning – Omkar Roy

November 27, 2021

Feedback by Omkar Roy, Graduated from the Department of Chemical Engineering in 2020, Graduate Engineer at Johnson Matthey

This micro specialization will allow the students to understand how the nature of fluid flow changes under severely confined conditions. The specialization will focus on how the effect of different forces changes/ get altered in the mesoscale, due to enhanced effect of surface tension, capillary forces as well as dispersion forces. The course will introduce to a student how scaling relations influence the transport properties at this length scale. Further, experimental investigation at this length scale also requires significant knowledge on micro and nanoscale fabrications. The specialization thus aims at covering the essential concepts of fluidics and microfabrication techniques, providing the students with advanced expertise and knowledge in this cutting edge area of research.

Source: Brief Description of the micro specialization curricula

Q.1 In your curriculum you had mandatory foundation courses Fluid Mechanics(ME60011) and Advanced Fluid Mechanics(CH61011) out of which you had to choose 1. Now ME60011 is quite disjunct from but a lot broader than any other UG depth course on fluid mechanics(MA40011, PH20101, CH20001 and ME21101) and so is CH61011 but apart from few introductory topics, the 2 courses diverge towards completely different regimes. Former focuses mostly on the physical characterization of various phenomena and systems while the latter focuses for a good part on turbulence modelling (major area of interest for larger length scales) and fluidization techniques.

What was your thought process of choosing one of them?

Response- So I did Advanced Fluid Mechanics(CH61011) which was my depth course in my final year and courses from component-2 before that. In most cases, the order matters unless permitted by Dean in special cases. One should check the prescribed guidelines for choosing subjects and enrolling as elective/ breadth/ additional subjects. For people from other departments, I would suggest the Fluid Mechanics(ME60011) course because CH61011 is an advanced level course and some fundamental understanding of fluid mechanics is required (at least a UG course on fluid mechanics). On the other side, ME60011 is self-complete and well-structured covering the basics very well.

Q.3 In Component-2 you had Microfluidics, Transport Phenomena(Depth), Intro to NanoTech and Microscale Energy Transport, out of which you had to choose 2. Which subjects did you choose?

Response- Apart from Transport Phenomena I chose all of them.

Q.4 So from the course content Microfluidics apparently covers a very broad range of applications and techniques starting from the very basics. What are your views on this course?

Response: It is a really good course. It was taught to me by Prof. Suman Chakraborty and he was brilliant. He covered a broad spectrum of the field- Theory and Experiments. For the experimental aspects which gives a boost to the overall understanding, we were given live demonstrations in the lab and were given assessment, prediction and analysis based questions as graded assignments based on those demonstrations. I did this course in Spring, 2019 and I have been informed that in Spring 2020, there were a few welcoming changes like use of Matlab for flow visualization.

Industrial Importance:

Response: In the well-flourished sectors, pharmaceutical R&D has extensive use of microfluidics and biomicrofluidics which is also extensively used in the development of novel medical technologies. And for these sectors, a person does not have to be confined into biology or medical science. From the fundamental research point of view, it is a very rigorous field and for applications, many cutting edge technologies are being developed on its grounds. For example, lab-on-a-chip technology or recent research by Prof. Chakraborty’s group on generating electricity from wet clothes. In the computational modelling and simulation subfield, many novel methods like the molecular dynamic model, multi-scale model etc. are being developed in the microfluidic regime since the already existing models like continuum model etc fail to predict various phenomena that occur at the micrometer scale. You may have heard of Theranos and Elizabeth Holmes. If you haven’t it’s worth knowing. Although, the startup could not deliver on its promises (some analysts describe them as scam/fraud) the ideas they conveyed were powerful.

NPTEL course on microfluidics by Prof. Suman ChakrabortyKGP’s invention of creating electricity from wet clothesSome latest works on BiomicrofluidicsSome Latest works on MicrofluidicsLab-on-a-chip TechnologyKrell Institute Course on Multi-Scale ModellingTheranos Corporation

Q.5 So this course on Intro to NanoTech follows a very unique structure. The pre-midsem syllabus is the same for all the students. But post-midsem syllabus is separately prepared into 4 modules for students from different groups of disciplines. 1. Physical, electrical and material science, 2. Chemistry and Biology, 3. MT, 4. Microfluidics and Nanopatterning. What do you think about this structure and course?

Response: Many techniques from Physics/Material/Electrical Science are also taught in the common module. My module curriculum comprised a broad range of experimental techniques like atomic force microscopy which lets you investigate topography of surfaces with a resolution of fractions of a nanometer and patterning techniques like lithography. This module was conducted by Prof. Rabibrata Mukherjee used to teach all the topics of fundamental relevance from real-life examples and experimental techniques brilliantly in a classroom environment.

Industrial Importance:

Response: Patterning techniques like photo-lithography etc are useful in semiconductor fabrication, and other areas but especially the semiconductor industry demands a higher level of skill set and knowledge base (preferably professionals with a physics/material science background pursue). This course is a good introductory course for further advancement.

Animation on how atomic force microscopy worksMicro and Nanopatterning

Q.6 Now from the course content of Microscale Energy Transport and the references suggested for this course(like some standard books on quantum mech, solid-state and semiconductor physics), it raises a doubt: Will it be quite hectic those undergrads who didn’t take any basic courses on QM like Physics-2 or Semiconductor Physics(EC21107)?

Response: No, QM and solid-state physics are not needed to handle this course. Actually the course content apparently hasn’t been updated for a long time. As a base, the course Transport Phenomena could be useful. Many engineering approaches to design and develop microchannels, heat pipes and the usage of various devices is taught. At the end of the course, students are supposed to prepare a term paper, basically a presentation on any topic of relevance (approved by the concerned faculty).

Industrial Importance:

Response: This is used in areas like electronic chip cooling and heat sinks etc but the field has quite stagnated now from the RnD aspect.Various fabrication methods taught in this course, may be helpful for students looking for a career in research related to experimental material science.

Q.7 In component-3 you had only one-course Instability and Patterning of Thin Polymer Films. What would you say about this course? And what things does patterning deal with?

Response: This course was also taught by Prof. Rabibrata Mukherjee and many techniques of research and industrial relevance were taught broadly. One may find similarity in the initial introductory lectures to the module-2 (that I chose) of Intro to Nano lectures. After the initial few classes, the spectrum gets much wider, vivid and enjoyable. Topics like AFM and photolithography are taught at much higher details. Hydrodynamics at interface and their analytical models are also a core component of the course. Patterning basically comprises creating very specifically designed patterns on surfaces of solids, required for very specific purposes. For example- Leaf of a lotus is superhydrophobic(water drops slip away) and a drop sticks on a rose petal but does not wet it. These phenomena occur due to specific and different micrometer or nanometer small patterns on the surface of the leaves. So what if we had to create materials that mimic lotus leaves (self cleaning surface for) or rose petals for applications such as self cleaning photovoltaic panels. This is where techniques of patterning enter which are taught in this course. Paint and coatings(used in anti-reflective coating on lenses, screens) heavily rely on the hydrodynamics at the interface. He also arranged a demonstration session on AFM at the Central Research Facility.

Industrial Importance:

Response: The applications of the techniques are in many sectors but from the RnD aspect they are not that vigorous as they used to be. But from the research perspective this field is among the frontier ones and the nanotechnology as a whole is very interdisciplinary. The technological advancements being done around the world are evolving rapidly but not all are industrialized yet.

Superhydrophobic coatingPhotoresist Lithography

Q.8 How is the entire micro curriculum benefiting you in your current work?

Response: I work in the area of catalysis and I occasionally require CFD. I haven’t experienced the application of the other techniques yet. Divisions of my organization focusing on active pharmaceutical ingredients (API) and process technologies actively use many of the components taught in this micro.

Q.9 How strongly would you recommend it to students from those branches other than CH, ME, PH, MT or CY?

Response: Apart from these I would strongly recommend students from Biotechnology to explore this area. Biomicrofluidics has immense use in industry as well as research and they would have a great chance in this area if they are trained in this Micro-Specialization.

NPTEL course on BiomicrofluidicsSome latest works on Biomicrofluidics