Dr. Nandini Bhandaru, from the department of Chemical Engineering at IIT Kharagpur, has developed a technique for creating nanostructure surfaces which have excellent self-cleaning properties along with finding its potential in cancer treatment. This technique enables possible alignment of the self assembled nano domains in a thin polymer blend film using topographically patterned substrates and templates. This has similar properties as surface of lotus leaves from which a water drop rolls off automatically and takes along with it any accumulated dust. Such multi component films find wide application in various areas such as optoelectronic devices, plastic solar cells, biological scaffolds etc.
This research work has been well appreciated in the scientific community and has earned Bhandaru the prestigious "Young Scientist Award" from "Indian Science Congress Association" in the Theme "Engineering Science" for the year 2017 for her "Outstanding contribution to fundamental research in Nano Patterning of Soft Polymeric Blends and their application". She has also been conferred with the European Materials Research Society's (E-MRS's) Young Scientist Award in 2016 for her contribution to materials science.
"To give an idea, a nano meter is about one-thousandth part of the width of human hair! So at such scale creating ordered and patterned surfaces is extremely challenging as hands do not work at such small length scale and even the conventional machines and instruments fail such as robotic arms. Gravity is absent at nanoscale as well. My work is mainly related to modulating these forces at nanoscale such that the things organize by themselves, a process called self-assembly. I have mainly worked with polymeric materials and created nanostructures utilizing the concept of self-assembly in thin polymer films" explained Dr. Bhandaru.
"This is a rare feat by a student to be recognized with such awards for her doctoral thesis in India. What makes Nandini's work so fascinating that she tries to organize things at the nanoscale despite zero gravity. That is the hallmark of her research wherein she creates orders in such a way that she can create structures over large areas. She has made those structures and now we are in a position to explore some of their applications" said Prof. Rabibrata Mukherjee, Nandini's research guide and faculty at the Dept. of Chemical Engineering at IIT Kharagpur.
The novelty in this work is the development of techniques and methodologies to create nanostructures and multifunctional surfaces from multi-material systems by modulating the forces at nanoscale without depending on any major instruments and devices. These nanostructures can be fabricated on a large scale for less than Rs 100 while machine-made patterns cost Rs 30,000 to Rs 1 lakh for the same area.
The nano patterns fabricated by Nandini have already found application in diverse fields of microfluidics and nano biotechnology. In collaboration with a group in School of Medical Science and Technology at IIT Kharagpur, Dr. Bhandaru has looked into development of polymer blend based nano structured therapeutic patches having dual behavior on cells isolated from different conditions (normal, pre-cancer and cancerous). Presence of the patterns confines the adhesion and propagation of the cancer associated cells, thereby limiting their growth post surgery. Further, in another collaboration with the Microfluidics lab at the Institute, Dr. Bhandaru has studied fluid flow in a micro channel with internal nano structures and were able to develop surfaces with gradient wettability which means one part of the surface is water-loving and another part of the surface is water-hating. Such surfaces have excellent self-cleaning properties. Such surfaces could be used as water and oil repellent surface which presents a potential low-cost self-cleaning solution for solar cell panel street lights and glass facades in high-rise buildings. Besides, the presence of nanostructures can alter the property of the solar street lights by making them antireflective.
The research group led by Prof. Mukherjee in the Instability and Soft Patterning Laboratory at the department, is also engaged in developing oleophobic or oil repellent anti-fingerprint surfaces, which can be used widely in touchscreen devices. Most of the products developed by the group have been patented and the group is now working to scale up the techniques for industrial collaborations and product manufacturing.
Watch Interview of Prof. Rabibrata Mukherjee and Dr. Nandini Bhandaru