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“There’s plenty of room at the bottom”— the revolutionary talk by noted physicist and Nobel laureate Richard Feynman, in 1959, can be considered as to what laid the foundations for the field of nanotechnology. Recent years have seen a multitude of new emerging applications in this field. Commercial applications such as microfluidic devices that can manipulate tiny amounts of fluids, ‘lab-on-chip’ sensors used for drug delivery, accelerometers used for automobile air bag deployment and digital micromirror devices (DMDs) used in hi-definition TVs and video projectors in homes and theatres are merely the tip of the iceberg. In fact these micro/nano-electromechanical systems (MEMS/NEMS) are now believed to be the next logical step in the “silicon revolution”. It is estimated that the annual global impact of products where nanotechnology will play a key role will exceed US$ 1 trillion by 2015 and would require about 2 million nanotechnology workers. Promising as they may seem though, currently many potential applications for these devices have not really been practical. Several studies have shown that the tribology and mechanics of these devices are the limiting factors to the imminent broad based impact of nanotechnology on our everyday lives. For efficient and reliable MEMS/NEMS operation the most common potential failure mechanisms that need to be addressed are friction, adhesion, wear, fracture, fatigue, and contamination.

As part of the proposed research work, nanotribological studies will be performed to investigate properties that are critical to the design of reliable micro/nanoscale components. The primary concern while making these investigations is to be able to achieve sliding velocities that are close to those that most MEMS/NEMS, such as gear trains, micromotors, and microgas turbines that operate at  sliding velocities from several tens of mm/s to few m/s. The commercial atomic force microscope (AFM) setup does not provide the capability of emulating these operating speeds and hence a fundamentally new approach to measuring tribological properties has been devised and successfully implemented. Nanotribological investigations during the proposed research are expected to provide not only a fundamental understanding for behavior of materials as individual entities but also give a bigger picture that is necessary for developing newer, better and longer lasting solutions for the next generation nanodevices that are more reliable and efficient.

        Doctoral committee: Prof. Bharat Bhushan (Graduate Adviser), Prof. J. William Rich, Prof. Anthony Luscher &  Prof. Mark Walter

Publications

	Tambe, N. S. and Bhushan, B., "Nanoscale friction mapping", (submitted for publication)
	Tambe, N. S. and Bhushan, B., "Nanowear mapping: A novel atomic force microscopy based approach for mapping nanoscale wear at high sliding velocities", (submitted for publication)
	Tambe, N. S. and Bhushan, B., "Nanotribological characterization of self assembled monolayers deposited on silicon and aluminum substrates", (submitted for publication)
	Tambe, N. S. and Bhushan, B., "Friction model for velocity dependence of friction force", (submitted for publication)
	Tambe, N. S. and Bhushan, B., "Micro/nanotribological characterization of PDMS and PMMA used for BioMEMS/NEMS applications", Ultramicroscopy (in press)
	Tambe, N. S. and Bhushan, B., "Durability studies of micro/nanoelectromechanical systems materials, coatings and lubricants at high sliding velocities (up to 10 mm/s) using a modified atomic force microscope", Journal of Vacuum Science and Technology A (in press)
	Tambe, N. S. and Bhushan, B., "Identifying materials with low friction and adhesion for nanotechnology applications", Applied Physics Letters (in press)
	Tambe, N. S. and Bhushan, B., "Nanoscale friction induced phase transformation of diamondlike carbon", Scripta Materialia 52 (2005) 751-755
	Tambe, N. S. and Bhushan, B., "A new atomic force microscopy based technique for studying nanoscale friction at high sliding velocities", Journal of Physics D: Applied Physics (in press)
	Tambe, N. S. and Bhushan, B., "Scale dependence of micro/nano-friction and -adhesion of  MEMS/NEMS materials, coatings and lubricants", Nanotechnology, 15 (2004) 1561-1570 Abstract
	Tambe, N. S. and Bhushan, B., "In situ study of nano-cracking in multilayered magnetic tapes under monotonic and fatigue loading using an AFM", Ultramicroscopy, 100 (2004) 359-373  Abstract
	Tambe, N. S. and Bhushan, B., "Durability studies of head-disk interface using padded and load/unload picosliders for magnetic rigid disk drives", Wear, 255 (2003) 1334-1343  Abstract
	Bhushan, B., Wu, Y. and Tambe, N. S., "Sliding contact energy measurement using calibrated acoustic emission transducer", IEEE Transactions on Magnetics, 39 (2003) 881-887  Abstract
	Bhushan, B. and Tambe, N. S., "Role of particulate contamination on friction and wear and durability of load/unload and padded picosliders", IEEE Transactions on Magnetics, 39 (2003) 857-863  Abstract
	Tambe, N. S. and Bhushan, B., "Effect of load/unload process on friction/stiction and durability of head disk interface", Microsystem Technologies, 8 (2002) 409-418  Abstract

Book Chapter

Tambe, N. S. and Bhushan, B., "Investigations of the Velocity Dependent Nature of Nanoscale Friction, Adhesion and Wear ", in Springer Handbook of Nanotechnology, ed. Bhushan, B., 2nd edition, Springer-Verlag, Heidelberg, Germany (in preparation).

Assisted research work and related publications

	Friction and adhesion characterization of thin films used in a Digital Micromirror Device (DMD®)
	Bharat and Bhushan and Huiwen Liu, "Characterization of nanomechanical and nanotribological properties of digital micromirror devices", Nanotechnology, 15  (2004) 1785-1791
	Mechanical analysis of torsional spring members in a Digital Micromirror Device (DMD®)
	Huiwen Liu and Bhushan, B., "Nanotribological characterization of digital micromirror devices using an atomic force microscope", Ultramicroscopy, 100 (2004) 391-412.

Accepted abstracts

Tambe, N. S. and Bhushan, B., "Nanowear mapping: A novel atomic force microscopy based approach for mapping wear at high sliding velocities", World Tribology Congress III, Sept 2005.

Conferences and invited presentations

	American Vacuum Society, 51st International Symposium, Los Angeles, USA (2004)
	Scanning Probe Microscopy, Sensors and Nanostructures, Beijing-TEDA, China (2004)
	Scanning Probe Microscopy, Sensors and Nanostructures, Oxford, UK (2003)
	Wear of Materials, 14th International Conference, Washington DC, USA (2003)
	IEEE - Asia Pacific Magnetic Recording Conference (APMRC), Singapore (2002)
	ASME-Information Storage and Processing Systems (ISPS), 13th Annual Symposium, Santa Clara, CA, USA (2002)

 

Master's Thesis

Friction/stiction and durability of load/unload picosliders and padded picosliders in rigid disk drives (Abstract | PDF version)