Nano-Materials Science & Nano-Manufacturing
‘Nano-materials’ are a special genre of materials whose structural components are less than 100 nm* in size, at least in one dimension. Nano-material science is an interdisciplinary field concerned with the development of new nano-materials and improvement or enhancement of the existing nano-materials based on the structure-composition-synthesis-processing relationships between different materials. Based on the nanoscale dimension, nano-materials are classified as one-dimensional (e.g., thin films), two-dimensional (e.g., nanotubes) and three-dimensional (e.g., quantum dots). The two most prominent factors that differentiate the properties of nano-materials from the bulk materials are:
(a) Nano-materials have relatively larger surface area compared to the bulk material, resulting in high chemical reactivity, high mechanical strength and enhanced electrical properties.
(b) At nanoscale, quantum effects dominate the behavior of matter- affecting electrical, magnetic, optical and other properties of materials.
‘Nano-manufacturing’ is the science and engineering of the synthesis, fabrication and high precision manipulation of nanostructures and systems. Two different competing approaches are used in nanomanufacturing:
(a) Top down approach: Manufacturing starts on the macro scale and proceeds to create nanosized structures and features by processing the bulk material on a very fine scale.
(b) Bottom up approach: Manufacturing starts at the smallest possible scale (atomic and molecular level), and proceeds to create nanostructures by the process of self-assembly of atoms/molecules.
Some of the current application areas of nano materials are: cosmetics, composites, micro electronics, clays, coatings, tools, paints, displays, fuel cells, nano fibers, nanotube composites, lubricant, medical implants and many more. Scanning probe microscopy techniques such as, scanning tunneling microscope (STM) and atomic force microscope (AFM) have become the workhorses of nanotechnology and probe-based nanomanufacturing.
Here at the Materials and Manufacturing Research Laboratories (MMRL), we are continuously exploring novel nanomanufacturing methods to develop nanostructures and systems that are predictable in their performance, producible at a reasonable cost, and increase the productivity relative to existing technologies. Two prominent fields of nanotechnology research at MMRL are:
(a) Synthesis of hybrid nanoparticles for lubricant and thin film coatings
(b) Nanoscale probe-based machining- Nanoscale Electro-machining (nano-EM)
We have successfully developed a top down nanomanufacturing technique** for the synthesis of inorganic nanoparticles of hybrid composition with superior tribological properties. Various compositions of these inorganic nanoparticles have been used to develop oil-based and water-based nanolubricant formulations for use in boundary lubrication and minimum quantity lubrication (MQL) machining applications (abrasive grinding, deep-hole drilling and micromilling). The enhanced tribological properties of nanoparticles have been exploited to reduce detrimental frictional losses and material wear at the rubbing and sliding interfaces (steel-steel in boundary lubrication and tool-workpiece in machining). The use of nanoparticles based lubricants in MQL machining has not only proved to be highly production-efficient and economical as compared to conventional machining, but also a successful step towards green manufacturing.
In probe-based nanomanufacturing, Nanoscale Electro-machining (nano-EM) has emerged as one of the key manufacturing processes to sculpt, cut, pattern and allow in situ metrology at nanoscale for not only semi-conducting materials but also metallic substrates. Nano-EM is performed at the interface of a nanometrically sharp (< 50 nanometer (nm) probe diameter) cathode nano-tool and an atomically flat anode workpiece in the presence of n-decane (a linear polymeric alkane) dielectric molecular medium.
Under the guidance of Dr. Ajay P. Malshe, our research team which is comprised of highly determined and hard working students (undergraduate and graduate) along with our educational and industrial collaborators, are continuously working to develop novel and sustainable nanotechnology based solutions that would be beneficial to the human society.
1. A.P. Malshe, K.P. Rajurkar, K.R. Virwani, C.R. Taylor, D.L. Bourell , G. Levy, M.M. Sundaram, J.A. McGeough, V. Kalyanasundaram , and A.N. Samant, 2010, “Tip-based nanomanufacturing by electrical, chemical, mechanical and thermal processes”, CIRP- 599, In press.
2. Introduction to nanotechnology-